Veritas File System 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Storage Checkpoints
Storage Checkpoint Administration
Chapter 5 85
/dev/vx/dsk/fsvol/vol1:may_23 /fsvol_may_23
You can only mount a Storage Checkpoint clusterwide if the file system that the Storage Checkpoint belongs
to is also mounted clusterwide. Similarly, you can only mount a Storage Checkpoint locally if the file system
that the Storage Checkpoint belongs to is mounted locally.
You can unmount Storage Checkpoints using the umount command (see the umount_vxfs(1M) manual
page). Storage Checkpoints can be unmounted by the mount point or pseudo device name:
# umount /fsvol_may_23
# umount /dev/vx/dsk/fsvol/vol1:may_23
/dev/vx/dsk/fsvol/vol1 /fsvol vxfs defaults 0 2
/dev/vx/dsk/fsvol/vol1:may_23 /fsvol_may_23 vxfs clone=may_23 0 0
NOTE You do not need to run the fsck utility on Storage Checkpoint pseudo devices because
pseudo devices are part of the actual file system
Converting a Data Storage Checkpoint to a Nodata Storage Checkpoint
A nodata Storage Checkpoint does not contain actual file data. Instead, this type of Storage Checkpoint
contains a collection of markers indicating the location of all the changed blocks since the Storage
Checkpoint was created (“Types of Storage Checkpoints” on page 79)
You can use either the synchronous or asynchronous method to convert a data Storage Checkpoint to a
nodata Storage Checkpoint; the asynchronous method is the default method. In a synchronous conversion,
fsckptadm waits for all files to undergo the conversion process to "nodata" status before completing the
operation. In an asynchronous conversion, fsckptadm returns immediately and marks the
StorageCheckpoint as a nodata Storage Checkpoint even though the Storage Checkpoint’s data blocks are
not immediately returned to the pool of free blocks in the file system. The Storage Checkpoint deallocates all
of its file data blocks in the background and eventually returns them to the pool of free blocks in the file
system.
If all of the older Storage Checkpoints in a file system are nodata Storage Chekpoints, use the synchronous
method to convert a data Storage Checkpoint to a nodata Storage Checkpoint. If an older data Storage
Checkpoint exists in the file system, use the asynchronous method to mark the Storage Checkpoint you want
to convert for a delayed conversion. In this case, the actual conversion will continue to be delayed until the
Storage Checkpoint becomes the oldest Storage Checkpoint in the file system, or all of the older Storage
Checkpoints have been converted to nodata Storage Checkpoints.