BTRFS on boot since newest kernel update

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BTRFS on boot since newest kernel update

Postby phlomos » 2017-12-12 08:46

Hello,


I have a system booting from an BTRFS RAID1, which mounts a data disk during boot formatted as a BTRFS RAID5.
This worked until the most recent kernel update. Since then, I can't mount the data disk anymore during boot.
So what I do, is to deactivate in fstab the mount of the data disk, then reboot (now it boots without problems), then I go into fstab again, activate the data disk and then do a 'mount -a' and everything mounts and works.
So the same configuration that during boot can't mount, mounts, once booted, without a problem.
Here's my fstab:
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UUID=a74478fd-4141-4104-93ea-4e7f0c86b0c9 none        swap  sw                    0     0
UUID=84fea8a8-e2a6-48f2-a045-de41a116141c none        swap  sw                    0     0
LABEL=EFI        /boot/efi                   vfat  umask=0077                        0     1
LABEL=System  /                           btrfs compress,degraded,autodefrag,usebackuproot              0     1
LABEL=Home    /home                       btrfs compress,degraded,autodefrag,usebackuproot              0     0
LABEL=Home    /tmp                        btrfs compress,degraded,autodefrag,usebackuproot,subvolid=261 0     0
LABEL=Home    /usr/local/share/multimedia btrfs compress,degraded,autodefrag,usebackuproot,subvolid=262 0     0
/tmp                /var/tmp                    none  bind                                                    0     0


Thanks for any help
phlomos
 
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Joined: 2017-12-12 08:30

Re: BTRFS on boot since newest kernel update

Postby pylkko » 2017-12-12 21:10

AFAIK there was no recent kernel update... do you mean the 4.9.65 sec update?

How did you come up with this setup? Explain the disk arrragement please? Can you provide the outputs of
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# btrfs fi usage /
and
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# btrfs subvolume list -p /
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Re: BTRFS on boot since newest kernel update

Postby phlomos » 2017-12-13 07:05

Hello,

pylkko wrote:AFAIK there was no recent kernel update... do you mean the 4.9.65 sec update?
I don't know. I just had the message in WebMin, that in order to activate the latest kernel update, I should reboot.

pylkko wrote:How did you come up with this setup? Explain the disk arrragement please?
This server should amongst other things stream movies by DLNA. So I need some big disk space for the movies and music. But I also wanted to be sure, to always be able to boot, hence I chose a small system partition of 6GB on the 3 biggest disks and installed a RAID1 with the system on it. All the rest goes to a RAID5, mounted on /home, with sub volumes for tmp and multimedia (as you can see on the published fstab in my last post.

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# btrfs fi usage /
Overall:
    Device size:        12.00GiB
    Device allocated:         8.99GiB
    Device unallocated:         3.01GiB
    Device missing:           0.00B
    Used:            7.80GiB
    Free (estimated):         1.75GiB   (min: 1.75GiB)
    Data ratio:               2.00
    Metadata ratio:            2.00
    Global reserve:        16.00MiB   (used: 0.00B)

Data,RAID1: Size:3.96GiB, Used:3.72GiB
   /dev/sdh2      3.47GiB
   /dev/sdi2      2.50GiB
   /dev/sdj2      1.96GiB

Metadata,RAID1: Size:512.00MiB, Used:180.31MiB
   /dev/sdh2    256.00MiB
   /dev/sdi2    256.00MiB
   /dev/sdj2    512.00MiB

System,RAID1: Size:32.00MiB, Used:16.00KiB
   /dev/sdi2     32.00MiB
   /dev/sdj2     32.00MiB

Unallocated:
   /dev/sdh2    289.00MiB
   /dev/sdi2      1.22GiB
   /dev/sdj2      1.51GiB
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# btrfs fi usage /home
WARNING: RAID56 detected, not implemented
WARNING: RAID56 detected, not implemented
WARNING: RAID56 detected, not implemented
Overall:
    Device size:        10.89TiB
    Device allocated:           0.00B
    Device unallocated:        10.89TiB
    Device missing:           0.00B
    Used:              0.00B
    Free (estimated):           0.00B   (min: 8.00EiB)
    Data ratio:               0.00
    Metadata ratio:            0.00
    Global reserve:        16.00MiB   (used: 0.00B)

Data,RAID5: Size:8.00GiB, Used:4.93GiB
   /dev/sda      1.00GiB
   /dev/sdb      1.00GiB
   /dev/sdc      1.00GiB
   /dev/sdd      1.00GiB
   /dev/sde      1.00GiB
   /dev/sdg      1.00GiB
   /dev/sdh4      1.00GiB
   /dev/sdi3      1.00GiB
   /dev/sdj4      1.00GiB

Metadata,RAID5: Size:1.00GiB, Used:32.69MiB
   /dev/sda    128.00MiB
   /dev/sdb    128.00MiB
   /dev/sdc    128.00MiB
   /dev/sdd    128.00MiB
   /dev/sde    128.00MiB
   /dev/sdg    128.00MiB
   /dev/sdh4    128.00MiB
   /dev/sdi3    128.00MiB
   /dev/sdj4    128.00MiB

System,RAID5: Size:128.00MiB, Used:16.00KiB
   /dev/sda     16.00MiB
   /dev/sdb     16.00MiB
   /dev/sdc     16.00MiB
   /dev/sdd     16.00MiB
   /dev/sde     16.00MiB
   /dev/sdg     16.00MiB
   /dev/sdh4     16.00MiB
   /dev/sdi3     16.00MiB
   /dev/sdj4     16.00MiB

Unallocated:
   /dev/sda    929.86GiB
   /dev/sdb    929.86GiB
   /dev/sdc    929.86GiB
   /dev/sdd    929.86GiB
   /dev/sde    929.86GiB
   /dev/sdg    929.86GiB
   /dev/sdh4      1.81TiB
   /dev/sdi3    925.87GiB
   /dev/sdj4      2.72TiB
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# btrfs subvolume list -p /
# btrfs subvolume list -p /home
ID 261 gen 56997 parent 5 top level 5 path tmp
ID 262 gen 56997 parent 5 top level 5 path multimedia


Thanks
phlomos
 
Posts: 2
Joined: 2017-12-12 08:30

Re: BTRFS on boot since newest kernel update

Postby pylkko » 2017-12-13 09:53

There is the problem that RAID5 code is broken on kernel 4.9 and the developers advise against using it...

Since you are using the server only as a home media server, you should consider using a backported kernel and btrfs user space tools.

You might want to boot normally with the data disk mounting in fstab (I presum this is sdj) and then look at dmesg and journalctl for any possible error messages related to mounting it.e
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