Veritas Checkpoints -
SNAPSHOTS are a point in time copy of a filesystem.
Create:
mount –F vxfs –o snapof=origfs[,snapsize=size] destination snap_mount_point
Refresh:
mount –F vxfs –o remount, snapof=origfs[,snapsize=size] destination snap_mount_point
Remove:
umount snap_mount_point
Checkpoints are still better, they are persistent across a reboot and utilise fewer resources.
Primer by Par Botes
Here is a quick primer on checkpoints: (can you tell I really think
they
should be used instead of snapshots... :)
Checkpoints take
fewer resources than snapshots, they are persistent, you can
independently write to a checkpoint and they will survive a reboot.
Having said all of that... Both of them can handle multi terabyte
filesystem. Checkpoints will do it better and with fewer resource
consumption.
Create checkpoint:
fsckptadm -n create "a_name" /from_running_filesystem
List checkpoints:
fsckptadm list /from_running_filesystem
Mount checkpoint (default is readonly):
(note that each checkpoint get a pseudo /dev/vx/dsk/dg/ name)
mount -F vxfs -o ckpt=a_name /dev/vx/dsk/diskgroup/volname:a_name
/checkpoint_mount
Mounting it read/write:
mount -F vxfs -o ckpt=a_name,rw /dev/vx/dsk/diskgroup/volname:a_name
/checkpoint_mount
Umounting the checkpoint:
Umount /checkpoint_mount
Page 68 and onwards in the vxfs administration guide is a really good
read on checkpoint functionality.
-Par
This was posted by Par on the veritas mailing list.
