VERITAS File SystemÖ 3.5 (HP OnlineJFS/JFS3.5) AdministratorÆs Guide (December 2002)

Chapter 5
Storage Checkpoints
Storage Checkpoint Administration
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Accessing a Storage Checkpoint
You can mount Storage Checkpoints using the mount command (see mount_vxfs (1M)) with the mount option
–o ckpt=ckpt_name. Observe the following rules when mounting Storage Checkpoints:
• Storage Checkpoints are mounted as read-only Storage Checkpoints by default. If you need to write to a
Storage Checkpoint, mount it using the -o rw option.
• If a Storage Checkpoint is originally mounted as a read-only Storage Checkpoint, you can remount it as a
writable Storage Checkpoint using the -o remount option.
• To mount a Storage Checkpoint of a file system, first mount the file system itself.
• To unmount a file system, first unmount all of its Storage Checkpoints.
CAUTION If you create a Storage Checkpoint for backup purposes, do not mount it as a writable
Storage Checkpoint. You will lose the point-in-time image if you accidently write to the
Storage Checkpoint.
A Storage Checkpoint is mounted on a special pseudo device. This pseudo device does not exist in the system
name space; the device is internally created by the system and used while the Storage Checkpoint is
mounted. The pseudo device is removed after you unmount the Storage Checkpoint. A pseudo device name is
formed by appending the Storage Checkpoint name to the file system device name using the colon character
(:) as the separator.
For example, if a Storage Checkpoint named may_23 belongs to the file system residing on the special device
/dev/vx/dsk/fsvol/vol1, the Storage Checkpoint pseudo device name is:
/dev/vx/dsk/fsvol/vol1:may_23
To mount the Storage Checkpoint named may_23 as a read-only (default) Storage Checkpoint on directory
/fsvol_may_23, type:
# mount -F vxfs -o ckpt=may_23 /dev/vx/dsk/fsvol/vol1:may_23 \
/fsvol_may_23
The /fsvol file system must already be mounted before the Storage Checkpoint can be mounted. To remount
the Storage Checkpoint named may_23 as a writable Storage Checkpoint, type:
# mount -F vxfs -o ckpt=may_23,remount,rw \
/dev/vx/dsk/fsvol/vol1:may_23 /fsvol_may_23