Creating dataset can destroy existing data

[glipman]

Steps to reproduce:

Assume your volume is on /mnt/VOL1

1. On this volume create a new directory /mnt/VOL1/TEST1 (can be done in the Shell or in my case through a Samba share)
2. Create/copy files in that folder
3. Create a new dataset with name TEST1 (I remembered/decided I wanted it to be a dataset)
4. Result: all existing data in /mnt/VOL1/TEST1 is erased

Of course it is not the smartest thing I am trying to do here but if it so easy to destroy data using the interface FreeNAS should refuse or at least warn if the mount-point for the dataset already exists.

Side note: because the data came from another volume that was snapshotted restoring it from the snapshot was a breeze. Hurray ZFS.

(tested in 8.2.0 and 8.3.0RC2)

 

[toddos]

Have you tried deleting your test dataset to see if the old data is still there? That's generally how mount points work in *nix. They don't delete data in folders, they just hide it.

Note that I haven't bothered to test this, so it's quite possible datasets don't "mount" the same way regular drives do.

 

[glipman]

You are correct. When in a test-environment I delete the dataset the old files reappear.

A warning by FreeNAS might still be wise but at least no data was lost.

By now I found another user with the same problem at http://forums.freebsd.org/showthread.php?t=16673

And I recovered the data with http://forums.freenas.org/showthrea...m-by-creating-a-dataset-Need-consoling-advice