• Managing quotas

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    Managing quotas

    About file system quotas

    You can track and limit drive space consumption by configuring quotas for file systems at the file system or directory level. You can enable or disable quotas at any time, but it is recommended that you enable or disable them during non-peak production hours to avoid impacting file system operations.

    Note:  You cannot create quotas for read-only file systems.
    Quota configurations

    The storage system supports three types of quota configurations:

    Quota configuration
    Description
    User quota on a file system
    Limits the amount of storage consumed by an individual user storing data on the file system.
    Quota on a directory (called a quota tree once a quota is applied)
    Limits the total amount of storage consumed on the directory. You can use quota trees to:
    • Set storage limits on a project basis. For example, you can establish quota trees for a project directory that has multiple users sharing and creating files in it.
    • Track directory usage by setting the tree quota's hard and soft limits to 0 (zero).
    Note:  If you change the limits for a quota tree, the changes take effect immediately, without disrupting file system operations.
    User quota on a quota tree
    Limits the amount of storage consumed by an individual user storing data on the quota tree.
    Soft and hard limits

    A quota can have a soft limit, hard limit, or both.

    • A soft limit is a preferred limit on storage usage. The system issues a warning when a soft limit is reached.

      You can set a grace period for a file system or a quota tree, which counts down time once the soft limit is met. If the grace period expires, users cannot write to the file system or quota tree until more space becomes available, even if the hard limit has not been met.

      Note:  If you update the grace period value, the new value affects only the quota or quotas which will exceed the soft limit after the update is performed. Any existing quotas which have been counting down using the older grace period value will not be affected.
    • A hard limit is an absolute limit on storage usage.

      If a hard limit is reached for a user quota on a file system or quota tree, the user will not be able to write data to the file system or tree until more space becomes available. If a hard limit is reached for a quota tree, no user will be able to write data to the tree until more space becomes available.

    Recommended approach for configuring quotas

    It is recommended that you configure quotas before the storage system becomes active in a production environment, and that you follow this basic procedure:

    1. Create a file system.
    2. Determine which quota policy best suits the file system's environment, and select that policy. The default policy is File Size, which calculates drive usage in terms of logical file sizes, and ignores the size of directories and symbolic links.
    3. Enable the enforcement of user quotas at the file system level, and define default limits for those quotas. If default limits are not specified, the system sets no drive usage limits for users, unless explicit user limits are defined for each individual user. Set default quotas in an environment where you want the same set of limits applied to many users.
    4. Specify the grace period for which users of the file system can remain over the soft limit before it becomes the hard limit.
      Note:  If you update the grace period value, the new value affects only the quota or quotas which will exceed the soft limit after the update is performed. Any existing quotas which have been counting down using the older grace period value will not be affected.
    5. Define explicit quotas for individual users at the file-system level, if the environment requires this type of usage-control granularity. The explicit quotas you define supersede the default quota definitions.
    6. Create quota trees for each directory or subdirectory for which you want to have quotas.
    7. For each quota tree, optionally change the default limits for users at the quota tree level. These limits are inherited from file system settings when a quota trees is created. If default limits are not set, the quotas feature sets no drive usage limits for quota tree users, unless explicit user limits are defined for each individual user. Set default limits in an environment where you want the same set of limits applied to many users.
    8. For each quota tree, define explicit quotas for users if the environment requires this type of individual-usage-control granularity.

    Quota policies

    Before enabling and defining quotas, ensure that the file system is configured to use the quota policy that best suits the client environment:

    • File Size policy (default): Calculates drive usage in terms of logical file sizes, and ignores the size of directories and symbolic links. Use this policy where file sizes are critical to quotas, such as where user usage is based on the size of the files created, and exceeding the size limit is unacceptable.
      Note:  It is recommended that you use this policy for SMB file systems.
    • Blocks policy: Calculates drive usage in terms of file system blocks (8 KB units), and includes drive usage by directories and symbolic links in the calculations. With this policy, any operation resulting in allocating or removing blocks, such as creating, expanding, or deleting a directory; writing or deleting files; or creating or deleting symbolic links changes block usage. Block usage depends solely on the number of bytes added to or removed from the file.
      Note:  When using the Blocks policy, a user can create a sparse file whose size is larger than the file size, but that uses fewer blocks on the drive.
    If the grace period is set to 0, warnings will be generated when soft quotas are reached, the client will not get quota exceeded errors until the hard limit is exceeded. If the use of default soft quotas is required, set the specific grace periods you desire, or keep the default grace period of one week.
    Note:  If you update a grace period value, the new value affects only the quota or quotas which will exceed the soft limit after the update is performed. Any existing quotas which have been counting down using the older grace period value will not be affected.

    Enable or disable the enforcement of user quotas on a quota tree

    Enabling or disabling the enforcement of user quotas on a quota tree impacts system performance, but does not disrupt file system operations. It is recommended that you perform these operations only during non-peak production hours. Once user quota enforcement is enabled, you can change quota settings without impacting performance.

    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the file system, and then select the Edit icon.
    3. On the Quota tab, select the Quota Tree sub-tab.
    4. Do either of the following:
      • To enforce user quotas, locate the quota tree, and select the No link in the Enforce User Quotas column. Then select Enforce User Quotas.
      • To disable the enforcement of user quotas, locate the quota tree, and select the Yes link in the Enforce User Quotas column. Then clear Enforce User Quotas.

    Enable or disable the enforcement of user quotas on a file system

    Enabling or disabling the enforcement of user quotas on a file system impacts system performance, but does not disrupt file system operations. It is recommended that you perform these operations only during non-peak production hours. Once user quota enforcement is enabled, you can change quota settings without impacting performance.

    Note:  When you enable user quotas, you can also set default user quota limits and a default grace period. Explicit user quotas will override these defaults.
    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the file system, and then select the Edit icon.
    3. On the Quota tab, select the File System sub-tab.
    4. Select Manage Quota Settings.
    5. Select or clear Enforce User Quotas.
    6. If you are enabling user quotas, optionally do the following:
      • Change the quota policy for the file system.
      • Change the default quota limits and grace period. These limits apply to all file system users who do not have explicit user quotas defined. A value of 0 indicates no limit.

    Create a user quota on a file system

    Create a user quota on a file system to limit or track the amount of storage space that individual users consume on that file system. When you create or modify user quotas, you have the option to use default hard and soft limits that are set at the file-system level.
    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the file system, and then select the Edit icon.
    3. On the Quota tab, select the File System sub-tab.
    4. Select the Add icon.
    5. In the Create User Quota wizard, select the Add icon, and then provide the requested information. To track space consumption without setting limits, set Soft Limit and Hard Limit to 0, which indicates no limit.

    Create a quota tree on a file system

    Create a quota tree at the directory level of a file system to limit or track the total storage space consumed for that directory.
    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the file system, and then select the Edit icon.
    3. On the Quota tab, select the Quota Tree sub-tab.
    4. Select the Add icon.
    5. Follow the steps in the wizard. To track space consumption without setting limits, set the Soft Limit and Hard Limit fields to 0, which indicates no limit.

    Create a user quota on a quota tree

    Create a user quota on a quota tree to limit or track the amount of storage space that individual users consume on that tree. When you create user quotas, you have the option to use the default hard and soft limits that are set at the quota-tree level.
    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the file system, and then select the Edit icon.
    3. On the Quota tab, select the Quota Tree sub-tab.
    4. Select the quota tree, and then select the Edit icon.
    5. On the User Quotas tab, be sure that Enforce User Quotas is selected, and provide the limits information. To track space consumption without setting limits, set the Soft Limit and Hard Limit fields to 0, which indicates no limit.

    View file system storage space usage by user

    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the file system, and then click the Edit icon.
    3. Select the Quota tab to view the User Quota Report.

    View quota tree storage space usage

    You can view total quota tree storage space usage or quota tree space usage by user.
    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the file system, and then click the Edit icon.
    3. On the Quota tab, select the Quota Tree sub-tab.
      The system displays the total storage space usage by quota tree.
    4. To view quota tree storage space usage by user, select the quota tree, select the Edit icon, and then select the User Quotas tab.

    Change quota properties for a file system

    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the relevant file system, and then select the Edit icon.
    3. On the Quota tab, select the File System sub-tab.
    4. Change the limit settings for a user quota by selecting the quota and then selecting the Edit icon.
    5. Select Manage Quota Settings, and do any of the following:
      • Change the quota policy for the file system.
      • Enforce user quotas on the file system.
      • Change the default soft limit, hard limit, and grace period for new user quotas on the file system. You can change these values for individual user quotas when you create them or when you modify their properties.
        Note:  If you update the grace period value, the new value affects only the quota or quotas which will exceed the soft limit after the update is performed. Any existing quotas which have been counting down using the older grace period value will not be affected.

    Change properties for a quota tree

    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the relevant file system, and then select the Edit icon.
    3. On the Quota tab, select the Quota Tree sub-tab.
    4. Select the relevant quota tree, and then select the Edit icon.
    5. On the General tab, do any of the following:
      • Select Use Default Limits to keep the file system's default limits and grace period on the quota tree.
      • Clear Use Default Limits to override the file system's default limits and grace period.
      • Change the hard limit, soft limit, and grace period settings for the quota tree.
        Note:  If you update the grace period value, the new value affects only the quota or quotas which will exceed the soft limit after the update is performed. Any existing quotas which have been counting down using the older grace period value will not be affected.
    6. On the User Quotas tab, do any of the following:
      • Select or clear Enforce User Quotas to enable or disable the enforcement of user quotas on the quota tree.

        These actions impact system performance, but do not disrupt file system operations. It is recommended that you perform these operations only during non-peak production hours. You can change other quota settings without impacting performance.

      • If you enable the enforcement of user quotas on the quota tree, you can specify the soft and hard limits for those quotas. (You can override these values when you create individual quotas.)
      • Create a new user quota on the quota tree.
      • Edit properties for existing user quotas.

    Change the quota policy for a file system

    Changing the quota policy for a file system can impact system performance, because it causes a system rescan. Therefore, it is recommended that you perform this action during off-peak hours.
    Procedure
    1. Under Storage, select File > File Systems.
    2. Select the file system, and then select the Edit icon.
    3. On the Quota tab, select Manage Quota Settings.
    4. Change the quota policy, as desired.