The following example shows the difference between data Storage Checkpoints and nodata Storage Checkpoints.
To show the difference between Storage Checkpoints
/mnt0
, as in the following example:# mkfs -F vxfs /dev/vx/rdsk/dg1/test0
version 9 layout 134217728 sectors, 67108864 blocks of size 1024, log \
size 65536 blocks, largefiles supported # mount -F vxfs /dev/vx/rdsk/dg1/test0 /mnt0
# echo "hello, world" > /mnt0/file
/mnt0@5_30pm
, as in the following example:# 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
# cat /mnt0/file hello, world # cat /mnt0@5_30pm/file hello, world
# echo "goodbye" > /mnt0/file
# cat /mnt0/file goodbye # cat /mnt0@5_30pm/file hello, world
# umount /mnt0@5_30pm # fsckptadm -s set nodata ckpt@5_30pm /mnt0 # mount -F vxfs -o ckpt=ckpt@5_30pm \ /dev/vx/dsk/dg1/test0:ckpt@5_30pm /mnt0@5_30pm
# cat /mnt0/file goodbye
You can traverse and read the directories of the nodata Storage Checkpoint; however, the files contain no data, only markers to indicate which block of the file has been changed since the Storage Checkpoint was created:
# ls -l /mnt0@5_30pm/file -rw-r--r-- 1 root other 13 Jul 13 17:13 \ # cat /mnt0@5_30pm/file cat: input error on /mnt0@5_30pm/file: I/O error
# ls -l /mnt0@5_30pm/file -rw-r--r-- 1 root other 13 Jul 13 17:13 \ # cat /mnt0@5_30pm/file cat: /mnt0@5_30pm/file: I/O error