Host modes and host mode options

In the following conditions, Good Status is expected.

When this HMO is enabled, the storage system will switch Test Unit Ready response to Good Status from Reservation Conflict.

Use this HMO when any of the following conditions is met:

• Windows Server Failover Clustering (WSFC) is used.
• Microsoft Failover Cluster (MSFC) is used.
• Linux with cluster configuration is used.
• Symantec Cluster Server (previously known as Veritas Cluster Server (VCS)) is used.
• The response for SPC-3 (Good Status) is required.

• An Emulex host bus adapter is used in a Windows environment.
• The mini-port driver is used.
• TPRLO=2 is specified for the mini-port driver parameter of the host bus adapter.

However, in some cases, the host may expect Unit Attention.

When this HMO is enabled, the storage system will return the Unit Attention response.

Use this HMO when you want the Unit Attention (UA) response to be returned at SCSI path change (sense code: REPORTED LUNS DATA HAS CHANGED).

Note: If the UA response occurs frequently and the load on the host becomes high, the data transfer cannot be started on the host side and timeout might occur.

Note: Enable HMO 13 only when requested to do so.

* HACMP 4.5 version 4.5.0.13 or later, HACMP 5.1 version 5.1.0.4 or later, or HACMP 5.2 or later.

Oracle Solaris Cluster (Sun Cluster)

In the following condition, Normal Response is expected when a reserved volume receives the Mode Sense command from a node that is not reserving this volume.

When this HMO is enabled, the storage system will switch the Mode Sense command response to Good status from Reservation Conflict.

Use this HMO when Veritas Cluster Server is used, or an OS or middleware that supports SPC-4 is used.

Notes:

1. By applying HMO 22, the volume status (reserved / non-reserved) will be checked more frequently.
2. By applying HMO 22, the host OS will not be receiving warning messages when the Mode Select command is being issued to a reserved volume.

In the following conditions, Good Status (SPC-3 response) is expected.

When this HMO is enabled, the storage system will switch this command response to Good Status from Reservation Conflict.

Use this HMO when one of these conditions is satisfied:

• Windows Server Failover Clustering (WSFC) is used.
• Microsoft Failover Cluster (MSFC) is used.
• Symantec Cluster Server (previously known as Veritas Cluster Server (VCS)) is used.
• There is no registered key to be deleted when running the PERSISTENT RESERVE OUT command.

Note: Host types other than above listed in Special Direction expect the response when the option is set to OFF.

• You want to enable commands to assign nicknames to the devices.
• You want to set UUIDs to identify logical volumes from the host.

Note: When host mode 05 [OpenVMS] is used and HMO 13 is enabled, you must set the UUID to all LUs.

• Range of job resetting.
• Range of UAs (Unit Attentions) defined.

Use this HMO when you want to automate recognition of the DP-VOL capacity after increasing the DP-VOL capacity.

Note: This option is applied when UA returning to the host is required after the DP-VOL capacity is expanded.

Use this HMO when the VAAI (vStorage API for Array Integration) function of VMware ESX/ESXi 4.1 or later is used.

Notes:

1. The HMO is set to ON only when a VMware server of ESX/ESXi 4.1 or later using the VAAI (vStorage API for Array Integration) function is connected.
2. If the HMO is not applied, the VMWare support function, Cloning file blocks, cannot be used.
3. When the ESX 4.x server is connected, set HMO 54 to ON. HMO 63 is not necessary.
4. When the ESXi 5.x or ESXi 6.x server is connected, set both HMO 54 and HMO 63 to ON.
5. After setting HMO 54 to ON, perform an operation (such as a server reboot) leading to reissuing the Inquiry command from the host.

Use this HMO when you connect the storage system to VMware ESXi 5.0 or later and use the VAAI function for iSCSI T10.

Notes:

1. After setting this HMO, perform the operation, such as the server reboot that reissues the Inquiry command on the host side.
2. When ESXi 5.x or later is connected, set both HMO 54 and HMO 63 to ON.

Use this HMO when using the Page Reclamation function with a Linux host.

Notes:

1. The option is applied when Dynamic Provisioning is used by Linux 2.6.33 or higher.
2. After setting HMO 68 to ON, perform the operation (such as a server reboot) that reissues the Inquiry command from the host.

Use this HMO when a device file is blocked while a DP pool is blocked.

Note:

This option is applied if switching sense key/sense code returned as a response to Check Condition when a read/write I/O is received while a DP pool is blocked can prevent a device file from being blocked, and therefore the extent of impact can be reduced on host side.

Use this HMO if all of the following functions provided by Windows Server 2012 (WS2012) or later are used:

• Dynamic Provisioning function
• ODX function

Notes:

1. This option is applied when Dynamic Provisioning and ODX are used with Windows Server 2012.
2. After setting HMO 73 to ON, perform an operation (such as a server reboot) that reissues the Inquiry command on the host side.

Use this HMO if the following conditions are met:

• Global-active device is used in the configuration with the data centers (Metro configuration).
• HDLM is used as the alternative path software.

Notes:

1. The option is applied when GAD is used in HDLM environment built between long distance data centers. The option is only set to host groups of cross paths.
2. If the option setting is wrong, load balance of the path with the option set works incorrectly, which may cause a performance issue.

For instance, use this HMO:

• When connecting the storage system and the Open Enterprise Server of Novell Co., Ltd.
• When connecting the storage system and winBoot/i of emBoot Co., Ltd..

For instance: When the CHAP authentication is performed at the time of the discovery login in the iSCSI environment of the VMware host and storage system

• Configuring alternate paths between the VMware host and storage system.
• Waiting for replying of the target information from the ports other than ports of discovery login.

• Enabled: LUN path definition is enabled.
• Disabled: LUN path definition is disabled.

This HMO setting is not supported when the HDLM or VxVM DMP multipath software is used.

Notes:

1. Apply this HMO when all the following conditions are met:

   - You are using the NDM or GAD function to migrate volumes in multiple migration source storage systems that use the same server.

   - You need to converge target ports used on the migration target storage system.

   - Host mode 00, 01 03, 09, 0C, 0F, 21, or 2C is used.

2. Do not apply this HMO to host groups without the specified host modes enabled. Applying this HMO to host groups with other host modes can cause the following problems:

   - Path addition from the server to the migration target storage system might fail.

   - Display of devices that the server recognizes might be invalid.

3. When using VMware NMP, use the same LUN# for the migration source and migration target.
4. If a LUN path is defined from the host group to an LDEV defined in a virtual storage machine different from the one to which the host group belongs, this HMO cannot be set to OFF.

• Range of job resetting.
• Range of UAs (Unit Attentions) defined.

Proprietary ANCHOR command support

Note: This HMO was intended to be used only for NAS but was never implemented in NAS software, and therefore it is currently not supported by NAS and should not be used.

Use this HMO when ODX provided by Windows Server 2012 or later is used, in the environment with which the WS2012 or later host connects.

Notes:

1. After setting HMO 110 to ON, perform an operation (such as a server reboot) leading to reissuing the Inquiry command from the host.
2. When VMware and Linux servers, or VMware and Windows servers are added to the same host group, select VMware Extension for the host mode and then set the option to ON.
3. This HMO is related to HMO 73. For behaviors when both of the two options are set to ON, contact customer support.

   When both options are set to ON, the setting of HMO 73 is prioritized over that of HMO 110.

Note: The setting of this HMO applies to all iSCSI targets on the port. Therefore, set this HMO only in iSCSI target 00 of the port.

Use this HMO when connecting to VMware ESXi 6.5 or later, and when using the zero data page reclamation function which is performed automatically if files on the VMFS (Virtual Machine File System) are deleted.

Notes:

1. The option is applied to use Auto UNMAP with ESXi6.5 or later.
2. To enable the function, HMO 63 must be set to ON.
3. After setting HMO 114 to ON, perform an operation (such as a server reboot) leading to reissuing the Inquiry command from the host.

Note: If this option is set for a host other than a Windows/Linux/VMWare host, an I/O might not be issued from the host.

Use this HMO when an I/O performance problem occurs while Oracle ASM is used in Linux environment.

Notes:

1. The option is applied when an I/O performance issue occurs while Oracle ASM is used in a Linux environment. In other environments than Linux, the behavior when the option is used is not guaranteed.
2. This option is related to system option mode (SOM) 779.
3. After setting this HMO to ON, perform an operation (such as server reboot) by which the Inquiry command is run again on the host side.
4. With the support for this HMO, only the outside I/F is changed, but there is no change in cache used internally in the storage system. (because the cache in the storage system is equal to non-volatile memory by battery).