Thin Reclamation

Veritas File System (VxFS) supports reclamation of free storage on a Thin Storage LUN.

You reclaim free storage using the fsadm command or the vxfs_ts_reclaim API. You can perform the default reclamation or aggressive reclamation. If you used a file system for a long time and must perform reclamation on the file system, Symantec recommends that you run aggressive reclamation. Aggressive reclamation compacts the allocated blocks, which creates larger free blocks that can potentially be reclaimed.

You can specify the following thin reclamation options with the fsadm command:

-o aggressive

Initiates Thin Storage aggressive reclamation.

-o analyse|analyze

Initiates the analyze reclaim option.

-o auto

Initiates the auto reclaim option.

-P

Performs multi-threaded Thin Storage Reclamation. By default, the fsadm command performs single-threaded Thin Storage Reclamation. To use multi-threaded Thin Storage Reclamation, the array must support multiple concurrent reclaim operations.

-R

Performs reclamation of free storage to the Thin Storage LUN on a VxFS file system .

See the fsadm_vxfs(1M) and vxfs_ts_reclaim(3) manual pages.

Thin Reclamation is only supported on file systems mounted on a VxVM volume.

The following example performs default reclamation of free storage to the Thin Storage LUN on a VxFS file system mounted at /mnt1:

  # fsadm -R /mnt1

The following example performs aggressive reclamation of free storage to the Thin Storage LUN on a VxFS file system mounted at /mnt1:

  # fsadm -R -o aggressive /mnt1

After performing the reclaim operation, you can verify that the storage was reclaimed using the vxdisk -o thin list command.

Veritas File System also supports reclamation of a portion of the file system using the vxfs_ts_reclaim() API.

See the Veritas File System Programmer's Reference Guide.

Note:

Thin Reclamation is a slow process and may take several hours to complete, depending on the file system size. Thin Reclamation is not guaranteed to reclaim 100% of the free space.

You can track the progress of the Thin Reclamation process by using the vxtask list command when using the Veritas Volume Manager (VxVM) command vxdisk reclaim.

See the vxtask(1M) and vxdisk(1M) manual pages.

You can administer Thin Reclamation using VxVM commands.

See Thin Reclamation of a disk, a disk group, or an enclosure.