Experiment the snapshot function

bash-3.00# pwd
/mypool/vincent
bash-3.00# ls
bash-3.00# mkfile -nv 5m test1.file
test1.file 5242880 bytes
bash-3.00# cd /
bash-3.00# zfs snapshot
bash-3.00# cd /mypool/vincent/
bash-3.00# ls
test1.file
bash-3.00# mv test1.file test2.file
bash-3.00# ls
test2.file
bash-3.00# zfs rollback
cannot unmount '/mypool/vincent': 设备忙
bash-3.00# pwd
/mypool/vincent
bash-3.00# ls
test2.file
bash-3.00# cd /
bash-3.00# df -h -F zfs
Filesystem            Size  Used Avail Use% Mounted on
mypool                255M   29K  255M   1% /mypool
mypool/vincent        200M  156K  200M   1% /mypool/vincent
mypool/gary           555M   25K  555M   1% /mypool/gary
mypool/backup         255M   25K  255M   1% /mypool/backup
bash-3.00# zfs rollback
bash-3.00# df -h -F zfs
Filesystem            Size  Used Avail Use% Mounted on
mypool                255M   29K  255M   1% /mypool
mypool/gary           555M   25K  555M   1% /mypool/gary
mypool/backup         255M   25K  255M   1% /mypool/backup
mypool/vincent        200M  156K  200M   1% /mypool/vincent
bash-3.00# ls /mypool/vincent
test1.file
bash-3.00# cd /mypool/vincent/.zfs/snapshot/
bash-3.00# ls
monday/
bash-3.00# cd monday/
bash-3.00# ls
test1.file
bash-3.00# cd /