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Hitachi Vantara Knowledge

Maintenance of global-active device

You can perform maintenance on external storage while keeping GAD pairs.

Replacing the external storage system while keeping GAD pairs

You can replace the current external storage system with a new one while keeping GAD pairs.

CautionIf a GAD pair is not specified for the same quorum disk ID, delete the quorum disk first, and then re-create a quorum disk. When a GAD pair is not specified for the same quorum disk ID, if you replace the the quorum disk with a new one, the replacement might fail. When you re-create a quorum disk, create GAD pairs if necessary.

Procedure

  1. Check the pair operation mode for the blocked quorum disk.

    Depending on the check results, you might have to split the GAD pair.
    1. If the QM column output with pairdisplay -fcxe command is AA, the GAD pair is split.

      Go to step 2 if this is the case.

      If the QM column is other than AA, the GAD pair is not split in most cases. Go to step b.

      # pairdisplay -g oraHA -fcxe -d dev0
      Group PairVol(L/R) (Port#,TID, LU),Seq#,LDEV#.P/S,Status,Fence,%,
      P-LDEV# M CTG JID AP EM E-Seq# E-LDEV# R/W QM
      oraHA dev0(L) (CL1-C-0, 0, 0) 511111 400.P-VOL PAIR NEVER,100
      500 - - 0 1 - - - L/M AA
      oraHA dev0(R) (CL7-C-0,28, 0) 522222 500.S-VOL PAIR NEVER,100
      400 - - 0 1 - - - L/M AA
      
    2. Split the GAD pair if it is not already split.

      pairsplit -g oraHA -IH0
  2. If you split the GAD pair in step 1, resynchronize the GAD pair.

    pairresync -g oraHA -IH0
  3. Disconnect the GAD pair from the quorum disk.

    1. Disconnect the primary storage system from the quorum disk.

      raidcom disconnect external_grp -ldev_id 0x2045 -IH0
    2. Disconnect the secondary storage system from the quorum disk.

      raidcom disconnect external_grp -ldev_id 0x2045 -IH1
  4. Confirm that the GAD pair is disconnected from the quorum disk.

    1. Check if the primary storage system is disconnected from the quorum disk.

      (VSP 5000 series)

      raidcom get path -path_grp 1 -IH0
      PHG GROUP STS CM IF MP# PORT WWN PR LUN PHS
      Serial# PRODUCT_ID LB PM
      1 1-1 NML E D 0 CL5-A 50060e8008000140 1 0 NML 55555 VSP 5000 series N M D
      

      (VSP Gx00 models and VSP Fx00 models)

      raidcom get path -path_grp 1 -IH0
      PHG GROUP STS CM IF MP# PORT WWN PR LUN PHS
      Serial# PRODUCT_ID LB PM
      1 1-1 DSC E D 0 CL5-A 50060e8007823520 1 0 NML
      433333 VSP Gx00 N M
      
    2. Check if the secondary storage system is disconnected from the quorum disk.

      (VSP 5000 series)

      raidcom get path -path_grp 1 -IH1
      PHG GROUP STS CM IF MP# PORT WWN PR LUN PHS
      Serial# PRODUCT_ID LB PM
      1 1-1 NML E D 0 CL5-C 50060e8008000160 1 0 NML
      55555 VSP 5000 series N M D
      
      

      (VSP Gx00 models and VSP Fx00 models)

      raidcom get path -path_grp 1 -IH1
      PHG GROUP STS CM IF MP# PORT WWN PR LUN PHS
      Serial# PRODUCT_ID LB PM
      1 1-2 DSC E D 0 CL5-C 50060e8007823521 1 0 NML
      433333 VSP Gx00 N M
      
      
  5. Prepare a new quorum disk.

    1. Format the disk of a new external storage system.

    2. Map the formatted disk to the primary and secondary storage systems.

      Use the same procedure you use for creating a quorum disk. However, you do not need to set an external volume for the quorum disk.
  6. Check the status of the quorum disk.

    1. On the primary storage system, confirm that the status of the quorum disk is BLOCKED.

      (VSP 5000 series)

      raidcom get quorum -quorum_id 1 -IH0
      QRDID : 1
      LDEV : 2045
      QRP_Serial# : 511111
      QRP_ID : R9
      Timeout(s) : 30
      STS : BLOCKED
      
      

      (VSP Gx00 models and VSP Fx00 models)

      raidcom get quorum -quorum_id 1 -IH0
      QRDID : 1
      LDEV : 2045
      QRP_Serial# : 411111
      QRP_ID : M8
      Timeout(s) : 30
      STS : BLOCKED
      
      
    2. On the secondary storage system, confirm that the status of the quorum disk is BLOCKED.

      (VSP 5000 series)

      raidcom get quorum -quorum_id 1 -IH1
      QRDID : 1
      LDEV : 2045
      QRP_Serial# : 522222
      QRP_ID : R9
      Timeout(s) : 30
      STS : BLOCKED
      
      

      (VSP Gx00 models and VSP Fx00 models)

      raidcom get quorum -quorum_id 1 -IH1
      QRDID : 1
      LDEV : 2045
      QRP_Serial# : 422222
      QRP_ID : M8
      Timeout(s) : 30
      STS : BLOCKED
      
      
  7. Replace the old LDEV with a new one.

    1. On the primary storage system, replace the current external volume for the quorum disk with a new one.

      raidcom replace quorum -quorum_id 1 -ldev_id 1234 -IH0
    2. On the primary storage system, confirm that the status of the quorum disk is REPLACING.

      (VSP 5000 series)

      raidcom get quorum -quorum_id 1 -IH0
      QRDID : 1
      LDEV : 1234
      QRP_Serial# : 511111
      QRP_ID : R9
      Timeout(s) : 30
      STS : REPLACING
      
      

      (VSP Gx00 models and VSP Fx00 models)

      raidcom get quorum -quorum_id 1 -IH0
      QRDID : 1
      LDEV : 1234
      QRP_Serial# : 411111
      QRP_ID : M8
      Timeout(s) : 30
      STS : REPLACING
      
      
    3. On the secondary storage system, replace the current external volume for the quorum disk with a new one.

      raidcom replace quorum -quorum_id 1 -ldev_id 1234 -IH1
    4. On the secondary storage system, confirm that the status of the quorum disk is REPLACING.

      (VSP 5000 series)

      raidcom get quorum -quorum_id 1 -IH1
      QRDID : 1
      LDEV : 1234
      QRP_Serial# : 522222
      QRP_ID : R9
      Timeout(s) : 30
      STS : REPLACING
      
      

      (VSP Gx00 models and VSP Fx00 models)

      raidcom get quorum -quorum_id 1 -IH1
      QRDID : 1
      LDEV : 1234
      QRP_Serial# : 422222
      QRP_ID : M8
      Timeout(s) : 30
      STS : REPLACING
      
      
      Note

      If the raidcom replace quorum command is executed normally, the status of the quorum disk changes from BLOCKED to REPLACING in a few seconds. If the status does not change in a few minutes, contact customer support.

  8. Confirm that the status of the quorum disk is NORMAL.

    1. On the primary storage system, confirm that the status of the quorum disk is NORMAL.

      (VSP 5000 series)

      raidcom get quorum -quorum_id 1 -IH0
      QRDID : 1
      LDEV : 1234
      QRP_Serial# : 511111
      QRP_ID : R9
      Timeout(s) : 30
      STS : NORMAL
      
      

      (VSP Gx00 models and VSP Fx00 models)

      raidcom get quorum -quorum_id 1 -IH0
      QRDID : 1
      LDEV : 1234
      QRP_Serial# : 411111
      QRP_ID : M8
      Timeout(s) : 30
      STS : NORMAL
      
      
    2. On the secondary storage system, confirm that the status of the quorum disk is NORMAL.

      (VSP 5000 series)

      raidcom get quorum -quorum_id 1 -IH1
      QRDID : 1
      LDEV : 1234
      QRP_Serial# : 522222
      QRP_ID : R9
      Timeout(s) : 30
      STS : NORMAL
      
      

      (VSP Gx00 models and VSP Fx00 models)

      raidcom get quorum -quorum_id 1 -IH1
      QRDID : 1
      LDEV : 1234
      QRP_Serial# : 422222
      QRP_ID : M8
      Timeout(s) : 30
      STS : NORMAL
      
      

      If the raidcom replace quorum command is executed normally, the status of the quorum disk changes from REPLACING to NORMAL in a minute.

  9. If the status does not change in five minutes, check whether remote paths between the storage systems are in normal state.

  10. Confirm that the GAD pair you resynchronized is synchronized normally.

    Note

    When the quorum disk status changes from REPLACING to NORMAL due to a storage system failure, the quorum disk status of a storage system without a failure might not change from REPLACING in five minutes. When this happens, resynchronize the GAD pair after the failure is resolved. By this method, the status changes to NORMAL.

    Also, if you do not assign a quorum disk ID to a GAD pair after replacing a quorum disk, the quorum disk status does not change from REPLACING. In this case, we recommend deleting the quorum disk and then creating a new quorum disk before creating a GAD pair. If you want to create a GAD pair without deleting the quorum disk, perform step 8 again after creating a GAD pair.

    If the status of the quorum disk does not change after performing these methods, contact customer support.

    Note If the status of the quorum disk is FAILED, the primary storage system and the secondary storage system might be connected to different quorum disks. Specify the external volume so that the primary storage system and the secondary storage system are connected to the same quorum disk. After specifying the correct external volume, perform steps 8 through 10.

Expansion of DP-VOL capacity while keeping pair status

You can expand the capacity of a DP-VOL used in the GAD, TrueCopy, Universal Replicator, ShadowImage, or Thin Image pair created between or on the following storage systems while keeping the pair status in each software product.

  • VSP 5000 series: Microcode version 90-04-04-00/00 or later
  • VSP G/F350, G/F370, G/F700, G/F900: Microcode version 88-06-02-x0/00 or later
  • VSP E990: Microcode version 93-02-03-x0/00 or later
NoteThe expansion of DP-VOL capacity on the storage systems shown cannot be used with the expansion of DP-VOL capacity, which was supported for VSP G1x00, VSP F1500 with microcode version 80-06-74-xx/xx or later, while keeping a GAD pair status.

Expanding DP-VOL capacity used in GAD pair

When deciding to expand the capacity of a DP-VOL used as a volume in a GAD pair, understand that there are two different procedures, each depending on whether the GAD pair shares the same volumes with other software or does not share the same volumes. This procedure describes expanding DP-VOL capacity when the GAD pair does not share the volume (a GAD pair alone).

NoteOnly the assigned page capacity out of the DP-VOL capacity is counted as the GAD license capacity.

Before you begin

Ensure that the following conditions are met:
  • A V-VOL to be expanded is not an external volume
  • The LDEV format is being performed on a V-VOL to be expanded
  • A pool containing a V-VOL to be expanded meets any of the following conditions:
    • Normal condition
    • The used capacity of the pool exceeds the depletion threshold
    • The pool is being shrunk
  • A V-VOL to be expanded is a volume created on the storage systems described in Expansion of DP-VOL capacity while keeping pair status
  • Make sure that there is enough GAD license capacity for the page capacity assigned to the expanded volume capacity before the expansion

Procedure

  1. Verify that both the P-VOL and S-VOL of a GAD pair meet the prerequisites.

  2. Display the detailed information about the GAD pair on CCI.

    Verify whether the current differential data management method is the Shared memory (SM) difference management or the hierarchical difference management by a drive. The DM column displayed by the pairdisplay command shows whether the shared memory (S) difference management is applied or the hierarchical (D) difference management is applied.
    # pairdisplay -g oradb -fe
    Group PairVol(L/R) (Port#,TID, LU),Seq#, LDEV#.P/S,Status,Fence,Seq#, P-LDEV# M CTG JID AP EM E-Seq# E-LDEV# R/W QM DM P
    oradb dev1(L) (CL5-A-0,30, 0) 64568 301.P-VOL PAIR ASYNC,64568 303 - 0 2 1 - - - -/- AA S N
    oradb dev1(R) (CL5-A-0,30, 2) 64568 303.S-VOL PAIR ASYNC,----- 301 - 0 4 1 - - - -/- AA S N
    oradb dev2(L) (CL5-A-0,30, 1) 64568 302.P-VOL PAIR ASYNC,64568 304 - 0 3 1 - - - -/- AA D N
    oradb dev2(R) (CL1-A-0,30, 3) 64568 304.S-VOL PAIR ASYNC,----- 302 - 0 5 1 - - - -/- AA D N
    
    • If the SM difference management is applied, go to Step 3 to temporarily change to hierarchical difference management.
    • If the hierarchical difference management is applied, go to Step 4.
    • If using HDvM - SN, verify the advanced system settings No.5 and No.6.
      • If both the advanced system settings No.5 and No. 6 are set to Disable, the SM difference management is applied. Go to Step 3.
      • If either or both the advanced system settings No.5 and No.6 are set to Enable, the hierarchical difference management is applied. Go to Step 4.
  3. Change the differential data management method to the hierarchical difference management.

    1. Change system settings for hierarchical difference management.

      • If using CCI, set the system option mode (SOM) 1198 to ON and 1199 to OFF by using the raidcom modify system_opt command.

        Command example:

        raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode enable
        raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable
      • If using HDvM - SN, set the advanced system settings No. 5 to Enable and No.6 to Disable in the Edit Advanced System Settings window.
    2. Suspend the GAD pair.

    3. Resynchronize the GAD pair.

    4. Display the detailed information about the GAD pair on CCI.

      Verify that the current differential data management method is the hierarchical difference management.
  4. Suspend the GAD pair.

  5. Expand the S-VOL capacity in the GAD pair.

    • If using CCI, add -request_id auto option to the raidcom extend ldev command to specify the asynchronous command processing.

      Command example

      The following command expands the capacity of LDEV#44:44 by 10 GB.

      raidcom extend ldev -ldev_id 0x4444 -capacity 10G –request_id auto -IH1
    • If using HDvM - SN, expand the capacity in the Expand V-VOLs window.
  6. Verify that expanding the S-VOL capacity in the GAD pair is finished.

    • If using CCI, raidcom get command_status command to verify that the raidcom extend ldev command is finished processing.

      Command example

      raidcom get command_status -IH1raidcom get ldev -ldev_id 0x4444 -fx -IH1

      Verify the expanded LDEV capacity using the raidcom get ldev command.

    • If using HDvM - SN, select Logical devices from the Storage Systems tree, and then display the LDEV tab. Verify that the capacity with the target LDEV number is correct.
  7. Expand the P-VOL capacity in the GAD pair in the same way as the S-VOL capacity.

    If the P-VOL capacity in the GAD pair cannot be expanded, see Recovering from failure if one volume capacity in GAD pair cannot be expanded.
  8. Verify that expanding the P-VOL capacity in the GAD pair is complete in the same way as the S-VOL capacity.

  9. Resynchronize the GAD pair.

    If the resync operation in the GAD pair cannot be performed, see Recovering from failure if one volume capacity in GAD pair cannot be expanded.
  10. Verify that the pair statuses of both the P-VOL and S-VOL in the GAD pair have changed to PAIR (Mirror(RL)), and that the volume capacity is not being expanded.

    • If using CCI, check that the P column of the pairdisplay command displays N.
      # pairdisplay -g oradb -fe
      Group PairVol(L/R) (Port#,TID, LU),Seq#, LDEV#.P/S,Status,Fence,Seq#, P-LDEV# M CTG JID AP EM E-Seq# E-LDEV# R/W QM DM P
      oradb dev1(L) (CL5-A-0,30, 0) 64568 301.P-VOL PAIR ASYNC,64568 303 - 0 2 1 - - - L/M AA S N
      oradb dev1(R) (CL5-A-0,30, 2) 64568 303.S-VOL PAIR ASYNC,----- 301 - 0 4 1 - - - L/M AA S N
      oradb dev2(L) (CL5-A-0,30, 1) 64568 302.P-VOL PAIR ASYNC,64568 304 - 0 3 1 - - - L/M AA D N
      oradb dev2(R) (CL1-A-0,30, 3) 64568 304.S-VOL PAIR ASYNC,----- 302 - 0 5 1 - - - L/M AA D N
      

      The P column in the pairdisplay command displays the status that the volume capacity is being expanded. An N indicates that the volume capacity is not being expanded, an E indicates that the volume capacity is being expanded.

      The E status is displayed after expanding the P-VOL or S-VOL capacity in the GAD pair, and before performing the pair resync operation. This status changes to N after the resync operation completes.

    • If using HDvM - SN, check if the Processing Status field in the Remote Replication window is blank.

      Expanding is displayed if the volume capacity is being expanded.

  11. If you temporarily changed the differential data management method from SM difference to hierarchical difference (Step 2), restore to the SM difference management.

    1. To restore to the SM difference management:

      • If using CCI, set the system option mode (SOM) 1198 to OFF and 1199 to ON by using the raidcom modify system_opt command.

        Command example:

        raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
        raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode enable
      • If using HDvM - SN, set the advanced system settings No. 5 to Disable and No.6 to Disable in the Edit Advanced System Settings window.
    2. Suspend the GAD pair.

    3. Resynchronize the GAD pair.

    4. Display the detailed information about the GAD pair on CCI, and then verify that the current differential data management method is the SM difference management.

    5. If using CCI, and the settings of SOMs 1198 and 1199 have been changed, set SOM 1198 to OFF and 1199 to OFF by using the raidcom modify system_opt command.

      Command example:

      raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
      raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable

Expansion order policy when GAD pair shares the same volumes with other software

You can expand the capacity of DP-VOLs used in a GAD pair and each software pair when a GAD pair shares the same volumes with Universal Replicator (UR), ShadowImage (SI), and Thin Image (HTI).

When a GAD pair shares the same volumes with other software, the order in which you expand the DP-VOL capacity consists of the following two expansion orders:

  • Expansion order in a point to point configuration of the GAD pair
  • Expansion order in a point to point configuration of each software product
GUID-BBB27B75-3A82-4217-B5FD-79A0BD6426FC-low.png
  • When a remote replication (TC/UR/GAD) is included, first expand the S-VOL capacity on the end of the remote replication, and then expand the P-VOL capacity. For more information about the specific expansion procedure, see Expanding DP-VOL capacity when GAD pair is used with Universal Replicator
  • When a remote replication (TC/UR/GAD) shares the same volumes with a local replication (SI/HTI), first expand the capacity of the S-VOL group in the remote replication. The S-VOL group consists of the S-VOL in the remote replication and all volumes in the local replication with which the S-VOL shares the same volume. After expanding the capacity of the S-VOL group in the remote replication, expand the capacity of the P-VOL group in the remote replication. The P-VOL group consists of the P-VOL in the remote replication and all volumes in the local replication with which the P-VOL shares the same volume.

    The expansion order in each group follows the expansion order in the local replication. For more information about the specific expansion procedures, see Expanding DP-VOL capacity when GAD pair is used with ShadowImage and Expanding DP-VOL capacity when GAD pair is used with Thin Image.

  • In the local replication (SI/HTI), expand the capacity in the order from the highest layer to the lowest. The expansion order is not specified for the volumes in the same layer.

Expanding DP-VOL capacity when GAD pair is used with Universal Replicator

You can expand the capacity of DP-VOLs when pairs are created in a 3DC delta resync configuration with GAD and UR. For the detailed procedures for verifying the differential data management method, expanding the capacity, and verifying the expansion during the following procedure, see Expanding DP-VOL capacity used in GAD pair.

Before you begin

  • A V-VOL to be expanded is not an external volume.
  • The LDEV format is being performed on a V-VOL to be expanded.
  • A pool containing a V-VOL to be expanded meets any of the following conditions:
    • Normal condition
    • The used capacity of the pool exceeds the depletion threshold
    • The pool is being shrunk
  • When using GAD, TC, or DP-VOL, make sure that there is enough software license capacity for the page capacity assigned to the expanded volume capacity before the expansion.
  • A V-VOL to be expanded is created on a valid storage system. See Expanding DP-VOL capacity while keeping pair status.

Procedure

  1. Verify that each volume of the P-VOLs and S-VOLs in a GAD pair and DP-VOL pairs with which the GAD pair shares the same volumes meets the prerequisites.

  2. Display the detailed information about the GAD pair, UR pair, and UR delta resync pair on CCI.

    Verify whether the current differential data management method is the SM difference management or the hierarchical difference management by a drive.
    • If the SM difference management is applied, proceed to step 3.
    • If the hierarchical difference management is applied, proceed to step 4.
    • If using HDvM - SN, verify the advanced system settings No.5 and No.6.
      • If both the advanced system settings No.5 and No. 6 are set to Disable, the SM difference management is applied. Go to Step 3.
      • If either or both the advanced system settings No.5 and No.6 are set to Enable, the hierarchical difference management is applied. Go to Step 4.
  3. Change the differential data management method to the hierarchical difference management.

    1. Change system settings for hierarchical difference management.

      • If using CCI, set the system option mode (SOM) 1198 to ON and 1199 to OFF by using the raidcom modify system_opt command.

        Command example:

        raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode enable
        raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable
      • If using HDvM - SN, set the advanced system settings No. 5 to Enable and No.6 to Disable in the Edit Advanced System Settings window.
    2. Swap suspend the GAD pair.

      The delta resync operation can be performed automatically.
    3. Verify the pair statuses of the GAD pair, UR pair, and UR delta resync pair, and that the delta resync operation is complete correctly.

    4. Swap suspend the GAD pair again.

      The delta resync operation can be performed automatically.
    5. Verify the pair statuses of the GAD pair, UR pair, and UR delta resync pair, and that the delta resync operation is complete correctly.

    6. Display the detailed information about the GAD pair, UR pair, and UR delta resync pair on CCI, and then verify that the current differential data management method is the hierarchical difference management.

  4. Suspend the GAD pair and UR pairs.

  5. Expand each volume capacity, and then verify that the expansion is complete in the following expansion order:

    1. Expand S-VOL in the UR pair (S-VOL in the UR delta resync pair).

      If you cannot expanding the S-VOL capacity in the UR pair, expanding the P-VOL capacity in the GAD pair, or resynchronizing the GAD pair or UR pair, make sure to perform the recovery procedure described in Recovering from failure if one volume capacity in GAD pair cannot be expanded.
    2. Expand S-VOL in the GAD pair.

    3. Expand P-VOL in the GAD pair.

  6. Resynchronize the GAD pair and UR pair.

  7. Verify that both the pair statuses of the P-VOL and S-VOL in each pair of the GAD pair have changed to PAIR(Mirror(RL)) and in each pair of the UR pair have changed to PAIR.

    In addition, verify that each volume capacity in the GAD pair, UR pair, and UR delta resync pair is not being expanded.

    The following table shows how the expansion process is displayed.

    Expansion statusCCIHDvM - SN
    P column in the pairdisplay commandProcessing Status field in the Remote Replication window
    Not being expandedNBlank
    Being expandedE*Expanding*
    * These statuses have been displayed after expanding the P-VOL or S-VOL capacity in the GAD pair or the UR pair, and before performing the pair resync operation. After the resync operation is complete, the status is migrated to the Not being expanded status. In the UR delta resync pair, the Being expanded status will not be displayed on CCI or HDvM - SN because the expansion in the UR delta resync pair is complete concurrently with the GAD pair and the UR pair.
  8. In step 2, if the differential data management method is the SM difference management, restore to the SM difference management using the following procedure:

    1. To restore to the SM difference management:

      • If using CCI, set the system option mode (SOM) 1198 to OFF and 1199 to ON by using the raidcom modify system_opt command.

        Command example:

        raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
        raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode enable
      • If using HDvM - SN, set the advanced system settings No. 5 to Disable and No.6 to Disable in the Edit Advanced System Settings window.
    2. Swap suspend the GAD pair.

      The delta resync operation can be performed automatically.
    3. Verify the pair statuses of the GAD pair, UR pair, and UR delta resync pair, and that the delta resync operation is complete correctly.

    4. Swap suspend the GAD pair again.

      The delta resync operation can be performed automatically.
    5. Verify the pair statuses of the GAD pair, UR pair, and UR delta resync pair, and that the delta resync operation is complete correctly.

    6. Display the detailed information about the GAD pair, UR pair, and UR delta resync pair on CCI, and then verify that the current differential data management method is the SM difference management.

    7. If using CCI, and the settings of SOMs 1198 and 1199 have been changed, set SOM 1198 to OFF and 1199 to OFF by using the raidcom modify system_opt command.

      Command example:

      raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
      raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable

Expanding DP-VOL capacity when GAD pair is used with ShadowImage

You can expand the capacity of DP-VOLs used as pair volumes when a GAD pair is used with SI. This procedure provides an example for expanding the DP-VOL capacity in a configuration where the SI L1 pair and L2 pair are created for each volume of the P-VOL and S-VOL in the GAD pair. For the detailed procedures for verifying the differential data management method, expanding the capacity, and verifying the expansion during the following procedure, see Expanding DP-VOL capacity used in GAD pair.

Before you begin

  • A V-VOL to be expanded is not an external volume.
  • The LDEV format is being performed on a V-VOL to be expanded.
  • A pool containing a V-VOL to be expanded meets any of the following conditions:
    • Normal condition
    • The used capacity of the pool exceeds the depletion threshold
    • The pool is being shrunk
  • When using GAD, TC, or DP-VOL, make sure that there is enough software license capacity for the page capacity assigned to the expanded volume capacity before the expansion.
  • A V-VOL to be expanded is created on a valid storage system. See Expanding DP-VOL capacity while keeping pair status.
  • Ensure that the numbers of differential tables and pair tables required after the expansion do not exceed the maximum number allowed on the storage system. For information about calculating the number of tables, see Calculating the numbers of differential and pair tables for each pair.
.

Procedure

  1. Verify that each volume of the P-VOLs and S-VOLs in a GAD pair and SI pairs with which the GAD pair shares the same volumes meets the prerequisites.

  2. Display the detailed information about the GAD pair on CCI.

    Verify whether the current differential data management method is the SM difference management or the hierarchical difference management by a drive.
    • If the SM difference management is applied, proceed to step 3.
    • If the hierarchical difference management is applied, proceed to step 4.
    • If using HDvM - SN, verify the advanced system settings No.5 and No.6.
      • If both the advanced system settings No.5 and No. 6 are set to Disable, the SM difference management is applied. Go to Step 3.
      • If either or both the advanced system settings No.5 and No.6 are set to Enable, the hierarchical difference management is applied. Go to Step 4.
  3. Change the differential data management method to the hierarchical difference management.

    1. Change system settings for hierarchical difference management.

      • If using CCI, set the system option mode (SOM) 1198 to ON and 1199 to OFF by using the raidcom modify system_opt command.

        Command example:

        raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode enable
        raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable
      • If using HDvM - SN, set the advanced system settings No. 5 to Enable and No.6 to Disable in the Edit Advanced System Settings window.
    2. Suspend the GAD pair.

    3. Resynchronize the GAD pair.

    4. Display the detailed information about the GAD pair on CCI, and then verify that the current differential data management method is the hierarchical difference management.

  4. Suspend the GAD pair and all SI pairs.

  5. Verify the pair statuses of the SI pairs.

    The SI pair volume capacity can be expanded when the SI pairs are in the PSUS or PSUE status. Verify the current pair statuses of the SI pairs.
    1. If the pair statuses are not PSUS or PSUE, perform the pair operations.

    2. Ensure that the pair statuses are migrated to PSUS or PSUE.

  6. Expand each volume capacity, and then verify that the expansion is complete in the expansion order shown in the following figure.

    GUID-6C6032E1-DB59-4DE5-8B30-EB17D5741549-low.png After expanding the first volume capacity (S-VOL in the GAD pair), if you cannot expand the DP-VOL capacity in the SI pair, you cannot expand the P-VOL capacity in the GAD pair, or resynchronizing the GAD pair, make sure to perform the recovery procedure described in Recovering from failure if one volume capacity in GAD pair cannot be expanded.
  7. Resynchronize the GAD pair.

  8. Verify that both the pair statuses of the P-VOL and S-VOL in each pair of the GAD pair have changed to PAIR(Mirror(RL)).

    In addition, verify that each volume capacity in the GAD pair and SI pair is not being expanded.

    The following table shows how the expansion process is displayed.

    Expansion statusCCIHDvM - SN
    P column in the pairdisplay commandProcessing Status field in the Remote Replication or Local Replication window
    Not being expandedNBlank
    Being expandedE*Expanding*
    * These statuses have been displayed after expanding the P-VOL or S-VOL capacity in the GAD pair, and before performing the pair resync operation. After the resync operation is complete, the status is migrated to the Not being expanded status. In the SI pair, the Being expanded status is displayed for a while (30 seconds or so) after the expansion of the P-VOL and S-VOL capacity is complete. After that, the status is migrated to the Not being expanded status.
  9. In step 2, if the differential data management method is the SM difference management, restore to the SM difference management using the following procedure:

    1. To restore to the SM difference management:

      • If using CCI, set the system option mode (SOM) 1198 to OFF and 1199 to ON by using the raidcom modify system_opt command.

        Command example:

        raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
        raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode enable
      • If using HDvM - SN, set the advanced system settings No. 5 to Disable and No.6 to Disable in the Edit Advanced System Settings window.
    2. Suspend the GAD pair.

    3. Resynchronize the GAD pair.

    4. Display the detailed information about the GAD pair on CCI, and then verify that the current differential data management method is the SM difference management.

    5. If using CCI, and the settings of SOMs 1198 and 1199 have been changed, set SOM 1198 to OFF and 1199 to OFF by using the raidcom modify system_opt command.

      Command example:

      raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
      raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable
Calculating the numbers of differential and pair tables for each pair

If a DP-VOL exceeds 4 TB, the differential tables are placed in the hierarchy memory instead of the shared memory, and the differential tables in the shared memory are not used. Therefore, it is not necessary to calculate the number of differential tables for DP-VOLs over 4 TB.

Procedure

  1. Calculate how many differential tables are required for each pair.

    Use the following formulas:
    number-of-differential-tables-for-expansion = number-of-differential-tables-after-expansion - number-of-differential-tables-before-expansion
    number-of-differential-tables-per-pair = ceiling ((volume-capacity [KB] / 256) / 20,448)

    Ensure that the ceiling value enclosed in the parenthesis () is rounded up to the next integer.

  2. Calculate how many pair tables are required for each pair.

    Use the following formulas:
    number-of-pair-tables-for-expansion = number-of-pair-tables-after-expansion - number-of-pair-tables-before-expansion
    number-of-pair-tables-per-pair = ceiling ((number-of-pair-tables-per-pair / 36)

    Ensure that the ceiling value enclosed in the parenthesis () is rounded up to the next integer.

  3. Verify that the following numbers do not exceed the maximum number allowed on the storage system.

    • The total numbers of current pair tables and pair tables required for expanding the capacity
    • The total numbers of current differential tables and differential tables required for expanding the capacity

    You can check the numbers of differential and pair tables in the Local Replication window.

Expanding DP-VOL capacity when GAD pair is used with Thin Image

You can expand the capacity of DP-VOLs used as pair volumes when a GAD pair is used with HTI. This procedure provides an example for expanding the DP-VOL capacity in a configuration where the HTI L1 pair and L2 pair are created for each volume of the P-VOL and S-VOL in the GAD pair. For the detailed procedures for verifying the differential data management method, expanding the capacity, and verifying the expansion during the following procedure, see Expanding DP-VOL capacity used in GAD pair.

Before you begin

  • A V-VOL to be expanded is not an external volume.
  • The LDEV format is being performed on a V-VOL to be expanded.
  • A pool containing a V-VOL to be expanded meets any of the following conditions:
    • Normal condition
    • The used capacity of the pool exceeds the depletion threshold
    • The pool is being shrunk
  • When using GAD, TC, or DP-VOL, make sure that there is enough software license capacity for the page capacity assigned to the expanded volume capacity before the expansion.
  • A V-VOL to be expanded is created on a valid storage system. See Expanding DP-VOL capacity while keeping pair status.
  • A V-VOL to be expanded is not used in a pair with the clone attribute.
  • Ensure that the following numbers required after the expansion do not exceed the maximum number allowed on the storage system:
    • The snapshot estimated manageable capacity
    • The number of cache management devices
    • The subscription limit of the V-VOL capacity

    For information about calculating these numbers, see Calculating the snapshot estimated manageable capacity, the numbers of cache management devices, and the subscription limit of the V-VOL capacity.

Procedure

  1. Verify that each volume of the P-VOLs and S-VOLs in a GAD pair and HTI pairs with which the GAD pair shares the same volumes meets the prerequisites.

  2. Display the detailed information about the GAD pair on CCI.

    Verify whether the current differential data management method is the SM difference management or the hierarchical difference management by a drive.
    • If the SM difference management is applied, proceed to step 3.
    • If the hierarchical difference management is applied, proceed to step 4.
    • If using HDvM - SN, verify the advanced system settings No.5 and No.6.
      • If both the advanced system settings No.5 and No. 6 are set to Disable, the SM difference management is applied. Go to Step 3.
      • If either or both the advanced system settings No.5 and No.6 are set to Enable, the hierarchical difference management is applied. Go to Step 4.
  3. Change the differential data management method to the hierarchical difference management.

    1. Change system settings for hierarchical difference management.

      • If using CCI, set the system option mode (SOM) 1198 to ON and 1199 to OFF by using the raidcom modify system_opt command.

        Command example:

        raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode enable
        raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable
      • If using HDvM - SN, set the advanced system settings No. 5 to Enable and No.6 to Disable in the Edit Advanced System Settings window.
    2. Suspend the GAD pair.

    3. Resynchronize the GAD pair.

    4. Display the detailed information about the GAD pair on CCI, and then verify that the current differential data management method is the hierarchical difference management.

  4. Suspend the GAD pair.

  5. Verify the pair statuses of the HTI pairs.

    The HTI pair volume capacity can be expanded when the HTI pairs are in the PAIR, PSUS or PSUE status. Verify the current pair statuses of the HTI pairs.
    1. If the pair statuses are not PAIR, PSUS or PSUE, perform the pair operations.

    2. Ensure that the pair statuses are migrated to PAIR or PSUS.

  6. Expand each volume capacity, and then verify that the expansion is complete in the expansion order shown in the following figure.

    GUID-28BA7E68-A6F6-4959-92E8-5E19CE32FF09-low.png After expanding the first volume capacity (S-VOL in the GAD pair), if you cannot expand the DP-VOL capacity in the HTI pair, you cannot expand the P-VOL capacity in the GAD pair, or resynchronizing the GAD pair, make sure to perform the recovery procedure described in Recovering from failure if one volume capacity in GAD pair cannot be expanded.
  7. Resynchronize the GAD pair.

  8. Verify that both the pair statuses of the P-VOL and S-VOL in each pair of the GAD pair have changed to PAIR(Mirror(RL)).

    In addition, verify that each volume capacity in the GAD pair and HTI pair is not being expanded.

    The following table shows how the expansion process is displayed.

    Expansion statusCCIHDvM - SN
    P column in the pairdisplay or raidcom get snapshot commandProcessing Status field in the Remote Replication or HTI pairs window
    Not being expandedNBlank
    Being expandedE*Expanding*
    * These statuses have been displayed after expanding the P-VOL or S-VOL capacity in the GAD pair, and before performing the pair resync operation. After the resync operation is complete, the status is migrated to the Not being expanded status. In the HTI pair, the Being expanded status is displayed for a while (30 seconds or so) after the expansion of the P-VOL and S-VOL capacity is complete. After that, the status is migrated to the Not being expanded status.
  9. In step 2, if the differential data management method is the SM difference management, restore to the SM difference management using the following procedure:

    1. To restore to the SM difference management:

      • If using CCI, set the system option mode (SOM) 1198 to OFF and 1199 to ON by using the raidcom modify system_opt command.

        Command example:

        raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
        raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode enable
      • If using HDvM - SN, set the advanced system settings No. 5 to Disable and No.6 to Disable in the Edit Advanced System Settings window.
    2. Suspend the GAD pair.

    3. Resynchronize the GAD pair.

    4. Display the detailed information about the GAD pair on CCI, and then verify that the current differential data management method is the SM difference management.

    5. If using CCI, and the settings of SOMs 1198 and 1199 have been changed, set SOM 1198 to OFF and 1199 to OFF by using the raidcom modify system_opt command.

      Command example:

      raidcom modify system_opt -system_option_mode system -mode_id 1198 -mode disable
      raidcom modify system_opt -system_option_mode system -mode_id 1199 -mode disable
Calculating the snapshot estimated manageable capacity, the numbers of cache management devices, and the subscription limit of the V-VOL capacity

Procedure

  1. Calculate the snapshot estimated manageable capacity required for expanding the capacity of a Thin Image root volume.

    To expand the capacity of a Thin Image root volume, verify that the snapshot estimated manageable capacity is available. Use the following formulas:
    Snapshot-estimated-manageable-capacity-for-root-volume-expansion = Snapshot-estimated-manageable-capacity-after-root-volume-expansion - Snapshot-estimated-manageable-capacity-before-root-volume-expansion
    Snapshot-estimated-manageable-capacity = (Root-volume-capacity [TB] / 2.6 [TB]) x 3,024 [GB] + (168 [GB] x 2 (consumed-shared-memory [GB]))

    Expanding the volumes other than a root volume does not consume the snapshot estimated manageable capacity. You can check the snapshot estimated manageable capacity in the Local Replication window.

  2. Calculate the maximum number of cache management devices required for expanding the capacity of a Thin Image root volume.

    To expand the capacity of a Thin Image root volume, verify that the cache management devices are available.

    Use the following formula:

    number-of-cache-management-devices-for-root-volume-expansion = ceiling ((Root-volume-capacity-after-expansion [TB] / 2.6 [TB])) - ceiling ((Root-volume-capacity-before-expansion [TB] / 2.6 [TB]))

    Ensure that the ceiling value enclosed in the parenthesis () is rounded up to the next integer.

    Expanding the volumes other than a root volume does not consume the cache management devices.

  3. Calculate the V-VOL capacity to be added by expanding the capacity of a Thin Image root volume.

    To expand the capacity of a Thin Image root volume, verify that the capacity after the expansion does not exceed the subscription limit of the V-VOL capacity contained in a DP pool.

    Use the following formula:

    V-VOL-capacity-added-by-root-volume-expansion = Thin Image-pair-capacity-calculated-based-on- root-volume-capacity-after-expansion - Thin Image-pair-capacity-calculated-based-on-root-volume-capacity-before-expansion
    Thin Image-pair-capacity = Σ ceiling ((Root-volume-capacity [MB] × number-of-pairs* × 2  / 42 [MB])) × 42 [MB]+ Σ ceiling ((Root-volume-capacity [MB] × number-of-pairs* × 2 / 2,921,688 [MB])) × 175,434 [MB]

    * Use the maximum number of HTI pairs to be created in the applicable snapshot tree as number-of-pairs instead of the number of pairs currently created in the applicable snapshot tree because the allocated pages are not released if you delete some pairs.

    Ensure that the ceiling value enclosed in the parenthesis () is rounded up to the next integer.

    Expanding the volumes other than a root volume does not add the V-VOL capacity contained in a DP pool in Thin Image.

Expansion order policy in configuration where P-VOL in remote replication shares the same volume with S-VOL in local replication

  1. Expand the volume capacity in the group that includes the S-VOL in the remote replication in the order shown as 1, 2, 3 in the preceding figure.

  2. Expand the volume capacity in the group that includes the P-VOL in the remote replication in the order shown as 4, 5, 6 in the preceding figure.

    Expand the volume capacity in the order from the highest layer to the lowest because the expansion order in the local replication is prioritized. Expand the P-VOL capacity in the local replication first, and then the S-VOL capacity in the local replication that shares the same volume with the P-VOL in the remote replication.

    For example, when an S-VOL in SI shares the same volume with a P-VOL in TC or UR as shown in the preceding figure, expand the volume capacity in the following order:

    1. P-VOL in the SI pair shown as 4 in the figure.
    2. S-VOL in the SI pair (P-VOL in the TC or UR pair) shown as 5 in the figure.
    3. Volumes in the same layer as the S-VOL in the SI pair.
    4. Volumes in the lower layer than the S-VOL in the SI pair.

Expansion order policy in 3DC cascade, 3DC multi-target, or 3DC delta resync configuration with remote replications

When a 3DC cascade, 3DC multi-target, or 3DC delta resync configuration using remote replications is created, first expand the S-VOL capacity on the end of the remote replication, and then expand the P-VOL capacity as shown in the following figures.

  • 3DC cascade configuration

    GUID-E1F91536-351D-4BE8-8782-DF58E5483EE2-low.png

  • 3DC multi-target configuration

    GUID-C5016543-C8F9-4ED9-8CA7-77384707CFAB-low.png

  • 3DC delta resyc configuration

    GUID-A0B28F5B-C749-429B-B086-B61D6A174B1F-low.png

Expansion order when remote replications in a 3DC cascade configuration share the same volumes with local replications (ShadowImage/Thin Image)

When the remote replications in a 3DC configuration share the same volumes with the local replications (SI/HTI), expand the volume capacity in each following group in the order as shown in the figure.

GUID-0F26984D-4589-428E-B97E-A546C507B91D-low.png

The expansion order in each group follows the expansion order in the local replication. In a 3DC multi-target or 3DC delta resync configuration, expand the volume capacity in the same way.

Procedure

  1. Expand the S-VOL group that consists of the S-VOL in the remote replication and all volumes in the local replication with which the S-VOL shares the same volume.

  2. Expand the P-VOL group that consists of the P-VOL in the remote replication and all volumes in the local replication with which the P-VOL shares the same volume.

Recovering from failure if one volume capacity in GAD pair cannot be expanded

If only one volume capacity in a GAD pair can be expanded while the other cannot be expanded, the resync operation in the GAD pair cannot be performed after the expansion because the capacity of both of the volumes is not the same.

If a GAD pair is used with Universal Replicator, ShadowImage, or Thin Image and the capacity of the P-VOL and S-VOL in one of the software products fails to expand, it causes the invalid state in which the expansion of the entire volume capacity is not complete. Perform the following operation to recover from the invalid state.

For more information about the I/O operations of the P-VOL and S-VOL in a GAD pair if the resync operation in a GAD pair cannot be performed, see I/O Modes.

Procedure

  1. Verify that all of the prerequisites are met.

    If the prerequisites are not met, proceed to step 4.
    1. Verify that both the P-VOL and S-VOL in a GAD pair meet the prerequisites for expanding the DP-VOL capacity.

      See the prerequisites for Expanding DP-VOL capacity used in GAD pair.

    2. Verify that all of the volumes meet the prerequisites for expanding the capacity in each of the software products.

      If a GAD pair is used with UR, SI, or HTI, the capacity of the P-VOLs and S-VOLs in all of the used software products must be expanded.
  2. When the prerequisites for expanding the DP-VOL capacity are met, retry the expansion and make sure that the capacity of the P-VOL and S-VOL in the GAD pair is the same.

    1. If there is not enough free space, increase the free space, and then expand the DP-VOL capacity.

    2. If a GAD pair is used with UR, SI, or HTI, retry the expansion and make sure that the capacity of the P-VOL and S-VOL in each of the software products is the same.

    • If you can expand the capacity, go to Step 3.
    • If you cannot expand the capacity, go to Step 4.
  3. Resynchronize the GAD pair.

    When a GAD pair is used with UR, resynchronize the UR pair. As a result, the recovery procedure from the failure is complete.
  4. Delete the GAD pair, expand the volume capacity in the SMPL status, and then re-create the GAD pair.

    • If you want to restore to the conditions before the expansion due to a capacity input error and others, delete the GAD pair, and then recreate the LDEV with the correct capacity. After that, recreate the GAD pair.
    • If a GAD pair is used with UR, Delete all pairs, expand the volume capacity in the SMPL status, and then restore the configurations by following the procedure for creating the configurations.

      If you want to restore to the conditions before the expansion due to a capacity input error and others, delete all pairs, and then recreate the LDEV with the correct capacity. After that, restore the configurations by following the procedure for creating the configurations.

    • If a GAD pair is used with SI or HTI, and the capacity of the P-VOL and S-VOL in a SI pair or HTI pair is not the same, you can only delete the SI pair or HTI pair. You can read the S-VOL data in the SI pair or HTI pair before the expansion. If you want to use the data before the expansion, delete all pairs after the data reading is complete. Expand the volume capacity in the SMPL status, and then restore the configurations by following the procedure for creating the configurations.

      If you want to restore to the conditions before the expansion due to a capacity input error and others, delete all pairs, and then recreate the LDEV with the correct capacity. After that, restore the configurations.

Recovering from failure if one volume capacity in GAD pair has been expanded

You can recover from a failure if only one volume capacity in a GAD pair can be expanded, while a failure occurs on the other volume before the expansion.

Procedure

  1. Start to recover from the failure using one of the global-active device disaster recovery procedures.

    Depending on the operations during the recovery procedure, one or more of the following actions are required:
    • If the operation is resynchronizing a GAD pair

      The resynch operation cannot be performed because the capacity of the P-VOL and S-VOL in the GAD pair is not the same.

      Complete Steps 2 and 3 before the GAD pair resynch operation.

    • If the operation is,
      • Deleting a GAD pair
      • Recovering from a volume failure
      • Re-creating a GAD pair

      The GAD pair cannot be created because the capacity of the target P-VOL and S-VOL is not the same when re-creating the GAD pair.

      Complete Steps 2 and 3 before the GAD pair resynch operation.

    • If the operation is,
      • Deleting a GAD pair
      • Deleting a volume
      • Creating a volume
      • Re-creating a GAD pair

      The GAD pair cannot be created because the capacity of the target P-VOL and S-VOL is not the same when re-creating the GAD pair. Make sure that the capacity of the P-VOL and S-VOL is the same when creating the volumes.

      Skip Steps 2 and 3.

  2. Expand the capacity of volumes whose capacity is not expanded, and then make sure that the capacity of the P-VOL and S-VOL in the GAD pair is the same.

    When a GAD pair is used with other software, the capacity of the P-VOLs and S-VOLs in all of the used software products must be expanded. For more information about the order in which the volume capacity is expanded, see Expansion order policy when GAD pair shares the same volumes with other software
  3. Restart the resync operation and the creation of the GAD pair by following one of the global-active device disaster recovery procedures.