[SOLVED] Proxmox 8.2.4 ZFS over ISCSI - Ubuntu 24.04 ISCSI Target

computerfreek

New Member
Aug 30, 2024
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Greetings all,

I'm new to Proxmox, but have been working with VMWare for years. I'm currently trying out different storage solutions for my home lab. My primary storage server has a combo of two pools: BigPool (hdds with SSD logs and cache) and BigSSD (all ssds). When I was running VMWare hosts, I was simply using TGT as the iscsi target and pointing the hosts to it. Since Proxmox, I've tried that, tried ceph, and wanted to give ZFS over ISCSI a go.

I've been able to setup the ISCSI Target to the point that Proxmox is able to connect to it and see the available space.
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However, when I try to move a VM or create a VM disk using the storage - I get this error:
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It creates the dataset within ZFS - but no data is moved:
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I did find this error/bug report: https://bugzilla.proxmox.com/show_bug.cgi?id=5071

And I tried to follow the workaround - but I don't have a /dev/zvol on my Ubuntu Storage box.
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My pools are mounted automatically to /BigPool and /BigSSD. I tried creating a link from this location back to /dev and that didn't have any effect. Am I missing something?


Storage Box (SGC)
Ubuntu 24.04
Running ZFS/SMB/targetcli
 

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So I went a little further. I reviewed this portion:
Looking at the plugin seems that the path is fixed at the code in the function get_base.
Code:
/usr/share/perl5/PVE/Storage/LunCmd/LIO.pm

sub get_base {
    return '/dev';
}
I think just changing that path to /dev/zvol will correct the plugin or maybe making some kind of detection to determine that path.

And due to not having a /dev/zvol folder or a /dev/POOL name folders. I changed the file on one of my hosts to this:
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This did something:
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But its still having an issue.
That path does exist:
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Its kind of weird still - the file vm-119-disk-0 is a symbolic link to something.
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I can't figure out whats its pointing to. I have no idea if that is actually the issue or not. For all I know its pointing to some /dev/zvol directory that doesn't exist.

Coming back to this part - Update here --- I found out that you can use "readlink" to find the full path. Even after destroying the pool and letting it recreate, it keeps pointing to /zd0 <-- Why?
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Even returning the code changed from '/dev' to '' above - made no change. The link keeps going to the wrong -- I think. There is nothing at /z*
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I did create links to BigPool in /dev/ and /dev/zvol/ - no effect.
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Last edited:
You changed to much ... the easiest fix is to create the symlink of the directory and nothing else:

Code:
ln -s /dev/zpool /dev/zvol

Your last screenshot shows that you messed with the detection path, which is not necessary to fix this. Maybe revert everything there is.

Please use text not screenshots of text ...
 
You changed to much ... the easiest fix is to create the symlink of the directory and nothing else:

Code:
ln -s /dev/zpool /dev/zvol

Your last screenshot shows that you messed with the detection path, which is not necessary to fix this. Maybe revert everything there is.

Please use text not screenshots of text ...
Thanks for the reply. I use screen shots because people have told me in the past - this form and others - that they didn't believe I made changes. So I take screen shots to proof it. This didn't fix it. It appears to be an issue with the newest version of OpenZFS. I downgraded to a previous version and the issue was resolved. Updated and the issue started up again. Thanks.
 

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