lvm snapshot cannot work when it takes on mounting files from network, so does zfs
 

I wanted to use snapshot to backup data from my windows on my openfiler, so I used lvm create a logic volume, and mounted it on /mnt/vg1/lv1, then I mounted windows files through cifs on /mnt/vg1/lv1/windows,then take a snapshot for lv1, but when I mounted the snapshot on /mnt/vg1/snapshot_lv1
there was nothing in /mnt/vg1/lv1/windows, why? I try this on zfs, there is also nothing. However, my boss told me that NetApp could. I cannot find solution with openfiler, can it do this with openfiler? I want to know how, so I ask for help here. so badly my English. thank you.

Hi Sunrise, that will never work, what you did was crate a LVM volume and mount over top of the volume, which means nothing on the LVM volume was written, you have just mounted your windows share ontop of the same mount point...

In Windows lingo, (if windows would let you) you have essentially renamed drive D: to C: without updating the original drive C: drive letter so now they are both drive C: then wondered were everything on the old drive C: went...

You can't use LVM snapshots externally, all snapshots must be within an LVM volume, you can't mount something over top of it and try to snapshot it, it doesn't work that way.

Hi /dev/random, thank you very much for your replay. I agree your point that it cannot work that way with LVM snapshot, but I learn that at least snapshotroot can do it, do you know any opensource applications can do it? And as I know all snapshots are for a volume or a file system, do you know any snapshot applications can make snapshot for files or directories? Thank you again.

Try rsnapshot

Thank you!!!