Unexpected mountpoint behavior

All your general support questions for OpenZFS on OS X.

Unexpected mountpoint behavior

Postby _max_ » Fri Feb 10, 2023 11:16 am

Zfs version: 1.9.3-0
MacOS version: High Sierra
HW: Mac Mini (late 2012)

Background: this all started as I was going to migrate my Plex setup from the Mac Mini (late 2012) to the new Mac Mini M2. For the "old Mini, the base system is on SSD and all of my storage is on an OWC TB3 8 drive ZFS pool named "zRaid1". This pool stores the different "media types" (each its own dataset) and also a separate dataset for the Plex configuration files (db's, metadata, etc) that are in "/Users/username/Library/Application Support/Plex Media Server". That data set is "zRaid1/Plex_Media_Server_App_Support" and I've set a mountpoint for it at "/Users/max/Library/Application Support/Plex Media Server". Everything worked fine (e.g., the mountpoint showed up where it should, and the Plex app worked just fine using the directory, snapshots were fine, etc).....until I exported the pool, and then re-imported it back on the same old Mini.

Issue: After export and then re-import, dataset mounted to the correct "subdirectory location", but it mounted using the "dataset name" instead of what was set in the mountpoint property.

Example / Events:
1. Dataset "zRaid1/Plex_Media_Server_App_Support" initially had the mountpoint property inherited from parent. So at creation it mounted to: "/Volumes/zRaid1/Plex_Media_Server_App_Support"
2. Issued: "zfs set mountpoint=/Users/max/Library/Application\ Support/Plex\ Media\ Server zRaid1/Plex_Media_Server_App_Support"
3. This worked as expected, with the unmount, rename, and mount occurring and the "Plex Media Server" directory showing up correctly as "/Users/max/Library/Application Support/Plex Media Server"
4. Everything worked for over a week with no issue, including the taking of nightly snapshots
5. Then issued a "zpool export zRaid1" and all of the datasets were unmounted the returned to command line with no errors.
6. Normal "Shut down" of the machine.
7. Normal power up the machine.
8. I thought I would have to "zpool import zRaid1", but ZFS just seemed to auto-import the pool at bootup. No big deal.
9. Then I ran a "zfs list" Again, all appeared "normal" and showed:
NAME USED AVAIL REFER MOUNTPOINT
zRaid1/Plex_Media_Server_App_Support 40.5G 19.3T 35.0G /Users/max/Library/Application\ Support/Plex Media Server
10. Then when I actually looked in the "Application Support" directory with Finder, instead of finding a "Plex Media Server" directory mounted, it showed the directory was name after the dataset "Plex_Media_Server_App_Support"
11. So what I actually have is:
"/Users/max/Library/Application\Plex_Media_Server_App_Support"
and NOT as the mountpoint was defined, and the expected behavior:
"/Users/max/Library/Application\Plex Media Server"

I have since tried to reset the mountpoint numerous times, back to default, then back to "/Users/max/Library/Application\ Support/Plex Media Server" to no avail. When mounted in "/Users/max/Library/Application\ Support/" directory, it always defaults to its dataset name of "Plex_Media_Server_App_Support"

Is this a known issue in prior versions that was reported (and fixed)? Or is there some other workaround?
As I'm now going to migrate to ZFS 2.1.6 on a new M2 Mac Mini, has this been remedied since?

(Note that I know I'm running an old version of ZFS, but I initially installed it w/Homebrew, and over time High Sierra became the latest MacOS upgrade I could perform, and then Homebrew left High Sierra behind, so then I got errors when trying to uninstall ZFS (so that I could upgrade to a new version). And Homebrew basically pukes all over my system now when I try to do anything with it as any package must be compiled from source, and latest versions have dependencies only available after High Sierra, etc., etc. Perhaps I've learned a lesson. Only installing ZFS as distributed on the openzfsonosx.org site.)

Thank you for any feedback on this.
_max_
 
Posts: 5
Joined: Fri Feb 10, 2023 4:24 am

Re: Unexpected mountpoint behavior

Postby roemer » Sat Feb 11, 2023 6:45 pm

I use nested datasets in a similar way for the meta-data directories of Photos and Lightroom photo archives with ZFS 1.9.4 (final release) and have no problems.
I am about to migrate to ZFS 2.1.6, and did some initial tests which so far seem to work as expected too.

You mentioned that you "looked in the "Application Support" directory with Finder".
Have you checked the actual path in a command line shell (Terminal) using ls?
Finder sometimes can show you 'display names' rather than the actual pathnames...
roemer
 
Posts: 73
Joined: Sat Mar 15, 2014 2:32 pm

Re: Unexpected mountpoint behavior

Postby _max_ » Sun Feb 12, 2023 8:52 pm

Haha. I actually thought about that when I wrote the post. I looked in Finder and in Terminal. Both showed the directory named as the dataset name, and not as the mountpoint name.

Anyway, I've moved on... I relented and just renamed the whole dataset from "Plex_Media_Server_App_Support" to "Plex Media Server" (which is what Plex expects it to be named) so whether this was a bug or not, it showed up in the "Application Support" directory with that "expected" name when mounted. I've since exported the pool and physically reconnected the OWC TB3 Drive bay to the new M2 Mac Mini which is running Zfs 2.1.6. It imported fine, and the (now renamed) "Plex Media Server" dataset was mounted in the "Application Support" directory as per the mountpoint setting...and Plex was happy.

It's interesting it was working "as expected" at one point, and it was only the export and re-import on the same system that brought up the issue. Perhaps this won't be an issue under 2.1.6 or later...

Thank you for responding though.

Regards.
_max_
 
Posts: 5
Joined: Fri Feb 10, 2023 4:24 am


Return to General Help

Who is online

Users browsing this forum: No registered users and 29 guests