Re: btrfs fails to mount on kernel 5.11.4 but works on 5.10.19

[Norbert Preining <norbert@preining.info>]

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Hi Chris,

thanks a lot for your email!

> Post the photo? This is a generic message and we need to see more
> information. Is devid 9 missing?

Yes it is missing. I attach the screenshot.

> Does the initrd on this system contain?
>   /usr/lib/udev/rules.d/64-btrfs.rules

Good question, I don't have access now since I am doing the 
	btrfsck --check-data-csum
which takes a bit of time. On a similar system (but without multiple
disks and no raid), but otherwise the same Debian/sid, I don't have
the rules file in the initrd (only in /lib/udev/rules.d/64-btrfs.rules
on the running system)

> That will wait until all devices are available before attempting to
> mount. If it's not in the initrd, it won't wait and it's prone to
> races, and you can often get mount failures because not all devices
> are ready to be mounted.

Ahh, ok that could be an issue - I will try to include the udev rules
and try again with 5.11.4. Strange that it didn't before, though.

> This seems to be a somewhat risky setup or at least highly performance
> variable. Any single device that fails will result in boot failure.

I had that, and it can normally be easily recovered via mounting in
degraded mode, removing or replacing the device, and reboot.
Worked last time ;-) What would your suggestion be instead?

> > hangs are fixed). Now I read that -rc1 is a btrfs-killer. I have swap

> That bug should not have affected the dedication swap partition case.

Good to hear, thanks!

Best

Norbert

--
PREINING Norbert                              https://www.preining.info
Fujitsu Research Labs  +  IFMGA Guide + TU Wien + TeX Live + Debian Dev
GPG: 0x860CDC13   fp: F7D8 A928 26E3 16A1 9FA0 ACF0 6CAC A448 860C DC13

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