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

Storage Checkpoints
Storage Checkpoint Administration
Chapter 586
NOTE You cannot convert a nodata Storage Checkpoint to a data Storage Checkpoint because a
nodata Storage Checkpoint only keeps track of the location of block changes and does not
save the content of file data blocks
Difference Between a Data and a Nodata Storage Checkpoint
The following example shows the difference between data Storage Checkpoints and nodata Storage
Checkpoints:
1. Create a file system and mount it on /mnt0:
# mkfs -F vxfs /dev/vx/rdsk/dg1/test0
version 6 layout
1024000 sectors, 512000 blocks of size 1024, log size 1024
blocks, largefiles supported
# mount -F vxfs /dev/vx/dsk/dg1/test0 /mnt0
2. Create a small file with a known content. Create a Storage Checkpoint and mount it on
/mnt0@5_30pm:
# echo "hello, world" > /mnt0/file
# fsckptadm create ckpt@5_30pm /mnt0
# mkdir /mnt0@5_30pm
# mount -F vxfs -o ckpt=ckpt@5_30pm \
/dev/vx/dsk/dg1/test0:ckpt@5_30pm /mnt0@5_30pm
3. Examine the content of the original file and the Storage Checkpoint file:
# cat /mnt0/file
hello, world
# cat /mnt0@5_30pm/file
hello, world
4. Change the content of the original file:
# echo "goodbye" > /mnt0/file
5. Examine the content of the original file and the Storage Checkpoint file. The original file contains the
latest data while the Storage Checkpoint file still contains the data at the time of the Storage Checkpoint
creation: