The rquotad protocol has been implemented as a service on the storage server. It functions as a read-only protocol and is only responsible for reporting information about user and group quotas. Quotas can be created, deleted, or modified through the Storage Management section of NAS Manager.
A UNIX/Linux NFS client can issue the quota command to retrieve information regarding quota usage of a user or group, based on their ID. The retrieved report contains block count, file count, quota limits on both, and other information (based on options invoked with the command). For accurate syntax, refer to the client's man pages, as implementation varies between client operating systems.
The server reports only Hard Limit quota information through rquotad. Three different quota limitations can be defined:
- User and group quotas to limit space and file quantity for individuals and groups within a virtual volume.
- User and group quotas to limit space and file quantity for individuals and groups within an entire file system.
- Virtual volume quotas to limit space and file quantity by a virtual volume as a whole.
The rquotad service can be configured to report quota information using one of two modes:
- Restrictive mode. For the user or group specified in the client-side quota command, the rquotad service reports the quota information for the quota with the most constraints.
- Matching mode. For the user or group specified in the client-side quota command, the rquotad service reports the quota information for the first quota that meets the parameters defined by the client-side quota command.
Restrictive mode operation
When in Restrictive mode, the rquotad service picks the first applicable quota threshold crossed. It enables the user to determine the amount of data that can be safely recorded against this quota before reaching its Hard Limit. This is the default configuration option for rquotad on the server.
If the user quota allowed 10 K of data and 100 files to be added, and the virtual volume quota allowed 100 K of data and 10 files to be added, rquota would return information stating that 10 K of data and 10 files could be added. Similarly, if the user quota is 10 K of data of which 5 K is used, and the virtual volume quota is 100 K of data of which 99 K is used, rquota would return information stating that 1 K of data could be added.
The console command rquota is provided to change between the two options, and also to disable access to quota information. For information on how to configure rquota, refer to the Command Line Reference.
Matching mode operation
When in Matching mode, the rquotad service follows a specific order to find a match for relevant quota information:
- If rquotad returns quota information for a user, it returns the user's quota within the virtual volume if it exists;
- Otherwise, it moves to the user's file system quota if that exists;
- If no file system quota exists for the user, then it will move to the virtual volume quota.
In this manner, rquotad keeps checking until a quota is found for the specified user or group. Once the first matching quota is found, rquotad stops searching and returns the quota information.
If a user does not have a specifically defined quota in a virtual volume, or in a file system, and the virtual volume quota allows all users 100 K of data and 10 files, rquotad would return information stating that user's quota is 100 K of data and 10 files. Similarly, if the user has a specified virtual volume quota that is 200 K of data and 20 files, and a file system quota that is 400 K of data and 40 files, rquotad would return information about only the first quota, stating that 200 K of data and 20 files could be added.