poolsize does not match sum of drive sizes at all (not even close)

[ilkerol]

Maybe I am somehow stupid, but I added 5 drives to one mergerfs pool (OMV latest version, i attached a screenshot):
3x 16,7 TB
2x 2,7 TB
(sda1, sdb1, sdc1, sdd1, sdf1)

I did not setup any parity stuff and no snapraid and so on yet. Just one pool with those drives, mounted to /srv/mergerfs/data. The weird thing is, that it shows up with 22TB capacity, not 55TB as it should be... all drives are formatted, each individual drive shows up with correct size when i check df -h. But the pool size is off by 33TB.

Does anyone have a clue what is going on here?

[trapexit]

Is that OMV? I don't own or maintain such 3rd party software so I can only speak to core mergerfs setups. If you wish to share your actual config and all the details I request in the support section of the docs then I might be able to help.

[trapexit]

I've never used OMV with mergerfs plugin. You'll need to talk to them about it if it isn't working as expected.

[ilkerol]

ok, then the issue really is that the added drives via the GUI do not really end up in the pool, although the omv gui clearly shows them as being part of it:
data
/srv/dev-disk-by-uuid-61930138-cd9b-4af6-9c8c-1a16c1d10bc3
/srv/dev-disk-by-uuid-ccfbfeb7-c0fc-4443-bcb8-c88d01b98fc3
/srv/dev-disk-by-uuid-ed92cdaf-cdec-4690-a638-9f03b7ddb1b0
/srv/dev-disk-by-uuid-0e298d89-359d-4349-88e8-517a0ccc364a
/srv/dev-disk-by-uuid-0d1e0dd0-b514-4ceb-be92-0fa4e55c2d5a

Think I will just manually add them to the mergerfs config... thank you a lot, just researching the required information made the problem obvious :)

[trapexit]

Did you restart after adding them? Did you check /etc/fstab or wherever it stores this info? The plugin doesn't change things live. While mergerfs does have a runtime API most every filesystem ever requires remounting for settings to change.

[ilkerol]

Maybe that was the issue... the omv frontend asks you to "apply pending changes" after everything you do, so I just assumed it would really apply changes. But apparently it didnt. I restarted the server and now it works. So their "apply pending changes" is not to be trusted. Good to know!

[trapexit]

It applies the changes to the config. But that doesn't mean the thing picks up those changes. If you change settings to some other mounted filesystem it won't remount the filesystem. Might be the same for random other things in OMV. Would be nice if it indicated the difference between config and runtime.

[ryecoaaron]

Please open a thread on the forum or an issue on github.
https://forum.openmediavault.org/
https://github.com/OpenMediaVault-Plugin-Developers/openmediavault-mergerfs/issues