btrfs cant mount -d single 4 volumes of different sizes hard drives

btrfs cant mount -d single 4 volumes of different sizes hard drives

[Chen Chiang CHAI]

Hello Sir,

my btrfs -d single(4 drives) is failing when one of my hard drive is
slowly dying.

because of that, i wanted to remove the hard drive thats responsible
for it, so i used btrfs device delete /dev/sdf after it mounted.
It was successful, so i have 3 drives left and its working.

So i physically removed the dying drive and move one of the working
drive to a different sata port( probably shouldnt have done that:
silly me )

Now when i start up my archlinux 4.11.10,
This problem occured as below:

Scanning for Btrfs filesystems
~ >>> sudo btrfs fi show
Label: none  uuid: 72977fa6-09de-43f0-a6db-ddfdbc668e50
Total devices 4 FS bytes used 1.02TiB
devid    1 size 465.76GiB used 195.01GiB path /dev/sdb
devid    3 size 931.51GiB used 659.03GiB path /dev/sdd
devid    5 size 1.82TiB used 194.03GiB path /dev/sde
*** Some devices missing

I tried to mount in -o degraded this the error it produced when dmesg ｜ tail
~ >>> dmesg | tail
                            [32]
[  382.410910] BTRFS error (device sdb): failed to read chunk tree: -22
[  382.442944] BTRFS error (device sdb): open_ctree failed
[  671.080860] IPv6: ADDRCONF(NETDEV_UP): wlp3s0: link is not ready
[  986.041955] IPv6: ADDRCONF(NETDEV_UP): wlp3s0: link is not ready
[ 1196.432643] BTRFS info (device sdb): allowing degraded mounts
[ 1196.432647] BTRFS info (device sdb): disk space caching is enabled
[ 1196.432648] BTRFS info (device sdb): has skinny extents
[ 1196.502252] BTRFS error (device sdb): super_num_devices 4 mismatch
with num_devices 3 found here
[ 1196.502256] BTRFS error (device sdb): failed to read chunk tree: -22
[ 1196.531619] BTRFS error (device sdb): open_ctree failed

search all over the net for that mismatch error.. only one mailing
list comes out saying something about using a tool to set
super_num_devices but there's no solution to it..

Sorry if my english is just weird not my first language.

Please help Thank you very much

sincerely yours,
Desparate Fool

Re: btrfs cant mount -d single 4 volumes of different sizes hard drives

[Chen Chiang CHAI]

I shoulda mentioned; I did change the sata port back but the same
error still occured..

Scanning for Btrfs filesystems
~ >>> sudo btrfs fi show
Label: none  uuid: 489e95eb-03c5-40e1-bd57-cd6e17584404
Total devices 1 FS bytes used 5.41TiB
devid    1 size 7.28TiB used 5.74TiB path /dev/sda

Label: none  uuid: 72977fa6-09de-43f0-a6db-ddfdbc668e50
Total devices 4 FS bytes used 1.02TiB
devid    1 size 465.76GiB used 195.01GiB path /dev/sdc
devid    3 size 931.51GiB used 659.03GiB path /dev/sde
devid    5 size 1.82TiB used 194.03GiB path /dev/sdd
*** Some devices missing

~ >>> sudo mount /dev/sdc /mediastuff -o degraded
mount: wrong fs type, bad option, bad superblock on /dev/sdc,
       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so.
~ >>> dmesg | tail
                            [32]
[   11.120313] Ebtables v2.0 registered
[   11.173684] IPv6: ADDRCONF(NETDEV_UP): wlp3s0: link is not ready
[   13.825637] r8168: enp4s0: link up
[   13.825675] IPv6: ADDRCONF(NETDEV_CHANGE): enp4s0: link becomes ready
[  116.017800] BTRFS info (device sdc): allowing degraded mounts
[  116.017804] BTRFS info (device sdc): disk space caching is enabled
[  116.017805] BTRFS info (device sdc): has skinny extents
[  116.033734] BTRFS error (device sdc): super_num_devices 4 mismatch
with num_devices 3 found here
[  116.033738] BTRFS error (device sdc): failed to read chunk tree: -22
[  116.057822] BTRFS error (device sdc): open_ctree failed
~ >>>

On Thu, Jul 20, 2017 at 5:06 PM, Chen Chiang CHAI <ccchai86@gmail.com> wrote:
> Hello Sir,
>
> my btrfs -d single(4 drives) is failing when one of my hard drive is
> slowly dying.
>
> because of that, i wanted to remove the hard drive thats responsible
> for it, so i used btrfs device delete /dev/sdf after it mounted.
> It was successful, so i have 3 drives left and its working.
>
> So i physically removed the dying drive and move one of the working
> drive to a different sata port( probably shouldnt have done that:
> silly me )
>
> Now when i start up my archlinux 4.11.10,
> This problem occured as below:
>
> Scanning for Btrfs filesystems
> ~ >>> sudo btrfs fi show
> Label: none  uuid: 72977fa6-09de-43f0-a6db-ddfdbc668e50
> Total devices 4 FS bytes used 1.02TiB
> devid    1 size 465.76GiB used 195.01GiB path /dev/sdb
> devid    3 size 931.51GiB used 659.03GiB path /dev/sdd
> devid    5 size 1.82TiB used 194.03GiB path /dev/sde
> *** Some devices missing
>
> I tried to mount in -o degraded this the error it produced when dmesg ｜ tail
> ~ >>> dmesg | tail
>                             [32]
> [  382.410910] BTRFS error (device sdb): failed to read chunk tree: -22
> [  382.442944] BTRFS error (device sdb): open_ctree failed
> [  671.080860] IPv6: ADDRCONF(NETDEV_UP): wlp3s0: link is not ready
> [  986.041955] IPv6: ADDRCONF(NETDEV_UP): wlp3s0: link is not ready
> [ 1196.432643] BTRFS info (device sdb): allowing degraded mounts
> [ 1196.432647] BTRFS info (device sdb): disk space caching is enabled
> [ 1196.432648] BTRFS info (device sdb): has skinny extents
> [ 1196.502252] BTRFS error (device sdb): super_num_devices 4 mismatch
> with num_devices 3 found here
> [ 1196.502256] BTRFS error (device sdb): failed to read chunk tree: -22
> [ 1196.531619] BTRFS error (device sdb): open_ctree failed
>
> search all over the net for that mismatch error.. only one mailing
> list comes out saying something about using a tool to set
> super_num_devices but there's no solution to it..
>
> Sorry if my english is just weird not my first language.
>
> Please help Thank you very much
>
> sincerely yours,
> Desparate Fool