Oopsie ... my files seem to have disappeared after fiddling with jails after upgrade to 9.2.1.6

[Chicken76]

Looking through the changes in the latest stable release, I saw some notes on a newer version of Samba and VirtualBox jails being added and I thought I'd give it a try.
I did the rutine upgrade from 9.2.1.5 to 9.2.1.6 without problems, then navigated to Jails, and went ahead with adding a Ubuntu jail into the default location, which was (supposed to be) a folder where I have the single share with all my data. Then I navigated through the share to see what was being written there, and to my surprise/horror, all the other data was gone. In that folder there was only the "jails" folder.
I the logged on via ssh and issued a "zfs list" with the following result.

Code:

NAME                                                   USED  AVAIL  REFER  MOUNTPOINT
matrice1                                              3.48T  1.85T  3.48T  /mnt/matrice1
matrice1/.system                                      6.61M  1.85T   234K  /mnt/matrice1/.system
matrice1/.system/cores                                 192K  1.85T   192K  /mnt/matrice1/.system/cores
matrice1/.system/rrd                                   192K  1.85T   192K  /mnt/matrice1/.system/rrd
matrice1/.system/samba4                               3.83M  1.85T  3.83M  /mnt/matrice1/.system/samba4
matrice1/.system/syslog                               2.17M  1.85T  2.17M  /mnt/matrice1/.system/syslog
matrice1/backups                                       884M  1.85T   202K  /mnt/matrice1/backups
matrice1/backups/jails                                 884M  1.85T   277K  /mnt/matrice1/backups/jails
matrice1/backups/jails/.warden-template-ubuntu-13.04   878M  1.85T   878M  /mnt/matrice1/backups/jails/.warden-template-ubuntu-13.04
matrice1/backups/jails/test1                          5.96M  1.85T   883M  /mnt/matrice1/backups/jails/test1

My data was in that /mnt/matrice1/backups folder, but as you can see, there are almost 3.5TB allocated to something that didn't show up, even in "ls" issued in a root console.

I then read in another thread here about unmounting and tried to issue a "zfs umount /mnt/matrice1/backups/jails" which failed, saying that the resource was in use. I deleted the test1 jail I had just created and then procedeed to unmount /mnt/matrice1/backups/jails/.warden-template-ubuntu-13.04, then /mnt/matrice1/backups/jails and finally /mnt/matrice1/backups. This did the trick! I now have my files back. I wonder what happens when I reboot this machine, ... do I have my files back or do I have to do the unmounts manualy every time?

So, for a simple case, where you only create one share, no separate datasets, the default location for jails is right there in the same path as all your data, and just fiddling with the Jails menu, thinking the defaults are safe, can get all your data unaccessible in an instant. There really should be some warnings or the default behavior changed to create a separate dataset that wouldn't overlap with anything user-created.

Did I do anything wrong?

 

[Chicken76]

Rebooted it today and when it comes back online the jails do overlap with my data, so I had to manually unmount them again.
How do I delete them permanently so they do not remount upon reboot? Doing "zfs destroy /mnt/matrice1/backups/jails/.warden-template-ubuntu-13.04" and then all the way to /mnt/matrice1/backups would do it?

 

[SweetAndLow]

I wouldn't mess with zfs destroy because it can be dangerous. I also don't think you have made a mount over a mount. I tried to configure something like that and using the gui it isn't possible. can you run a "ls -al /mnt/matrice1/backups" If I was you I would delete the datasets in the web gui that you don't need, not your backup dataset. then create a new dataset under your main pool called jails and then configure your jails to use that path.