Extraneous directory in /mnt

[Kevin Horton]

I'm trying to resolve a puzzle about an extraneous "/mnt/pool" directory on both my FreeNAS servers.

I used "pool" as the pool name when I set up my first machine. I learned pretty quickly that having "pool" as a the name of a pool caused some confusion when running various commands, so resolved to change it eventually. I've recently set up a second FreeNAS server, which would become my new main NAS, and the original one will be moved offsite as a replication target.

After getting the second server running, I named its main pool as "main", and its backup pool was "backup". I replicated "pool" from the first server to "main" on the second. Then I stopped the replication, and made the new server the main one. Then I destroyed the pool on the original server, added a couple more disks, then set it up with "main" as the pool name. Then I enabled replication from the "main" pool on new server to the "main" pool on the original server.

Now I find that each of the servers has an extraneous "/mnt/pool" directory, which only contains "/mnt/pool/jails", with four templates. The Jail Root is "/mnt/main/jails".

I wondered if this was some relic of the replication from "/mnt/pool" on the original machine to the new server, but I don't find any snapshots with "pool" in the name on either server, so I think that all relics of the "pool" pool should have been deleted as the various snapshots expired.

I've tried deleting those directories, but the system refuses, saying "Operation not permitted".

On the one hand, the servers are working apparently correctly, so perhaps I should just leave well enough alone. On the other hand, I wonder if these relics of the old "pool" pools may cause problems in the future. If there will be a problem, I'd rather find it and fix it before I move the original server offsite, as it will be PITA to get to its new location in the event things get so borked up that it requires an onsite visit.

Any advice and comments are appreciated.

Server details:

Original server:
X10SL7-F motherboard
G3258 CPU
16 GB ECC RAM
8 x 4TB WD Red drives in RAIDZ2
16 GB Supermicro SATA DOM as boot drive
Fractal Design Node 804 case

New server:
X10SRH-cF motherboard
E5 1650-v4 CPU
32 GB ECC RAM
8 x 4TB WD Red drives in RAIDZ2 as main pool
8 x 4TB WD Red drives in RAIDZ2 as backup pool
120 GB SANDisk
Norco RPC-4224 chassis

 

[nojohnny101]

If you don't mind me asking, does this extra "mnt/pool" show up in the GUI or only the CLI or both?

I was dealing with this at one point after multiple replications back and forth in the process of changing which box was my main server and which was one my backup (much as you described).

 

[Kevin Horton]

The extra "/mnt/pool" is only seen in the CLI. It is not seen in the GUI, nor does this phantom pool show up in the output of "zpool status".

 

[Kevin Horton]

The plot thickens.

Code:

zfs list -t all | grep pool
backup/jails/.warden-template-VirtualBox-4.3.12						  843M  13.8T   841M  /mnt/pool/jails/.warden-template-VirtualBox-4.3.12
backup/jails/.warden-template-pluginjail-9.3-x64						 582M  13.8T   580M  /mnt/pool/jails/.warden-template-pluginjail-9.3-x64
backup/jails/.warden-template-standard								  2.77G  13.8T  2.77G  /mnt/pool/jails/.warden-template-standard
backup/jails/.warden-template-standard-9.3-x64						  2.74G  13.8T  2.74G  /mnt/pool/jails/.warden-template-standard-9.3-x64
main/jails/.warden-template-VirtualBox-4.3.12							842M  13.8T   841M  /mnt/pool/jails/.warden-template-VirtualBox-4.3.12
main/jails/.warden-template-pluginjail-9.3-x64						   581M  13.8T   580M  /mnt/pool/jails/.warden-template-pluginjail-9.3-x64
main/jails/.warden-template-standard									2.77G  13.8T  2.77G  /mnt/pool/jails/.warden-template-standard
main/jails/.warden-template-standard-9.3-x64							2.74G  13.8T  2.74G  /mnt/pool/jails/.warden-template-standard-9.3-x64

The jail template snapshots have a mount point of /mnt/pool. That explains why /mnt/pool is hanging around, and why I cannot delete it.

I'm not sure how to put this right. I may be able to edit those mount points with commands like:

zfs set mountpoint=/mnt/main/jails/.warden-template-standard main/jails/.warden-template-standard

Other than having a backup of the data and the config, what else should I do to have a safety net if I were to attempt moving mountpoints?

 

[Kevin Horton]

I gritted my teeth, and did a zfs set mountpoint=/mnt/main/jails/.warden-template-standard main/jails/.warden-template-standard The output wasn't as clean as I had wished for, but it offered hope that a restart would allow things to mount properly:

Code:

cannot mount 'main/jails/.warden-template-VirtualBox-4.3.12': mountpoint or dataset is busy
property may be set but unable to remount filesystem

Sure enough, after a restart, all those jail templates now have a mountpoint in /mnt/main/jails, as desired. I'll wait a few days to see if everything is happy, then repeat this on my backup server (if the change doesn't get replicated over).

 

[nojohnny101]

Hmm interesting. Thanks for sharing and keep us updated if everything behaves in the next couple of days.

I was trying to think how I resolved the extra jail mount that I had, visible in the CLI but not in the GUI. It happened after I took all my data from my backup and replicated it back to my main box. It has been over 6 months though I can't remember how I eventually got it to clear. I know I didn't run the code you posted but I think it had something to do with completely wiping out my jail structure and then starting from scratch.