Re: RAID0 wrong (raw) device?

[Ulli Horlacher <framstag@rus.uni-stuttgart.de>]

On Fri 2015-08-14 (00:24), Anand Jain wrote:

> >> root@toy02:~# btrfs filesystem show
> >> Label: data  uuid: 411af13f-6cae-4f03-99dc-5941acb3135b
> >>          Total devices 2 FS bytes used 106.51GiB
> >>          devid    3 size 1.82TiB used 82.03GiB path /dev/drbd2
> >>          devid    4 size 1.82TiB used 82.03GiB path /dev/drbd3
> >
> > And now, after a reboot:
> >
> > root@toy02:~/bin# btrfs filesystem show
> > Label: data  uuid: 411af13f-6cae-4f03-99dc-5941acb3135b
> >          Total devices 2 FS bytes used 119.82GiB
> >          devid    3 size 1.82TiB used 82.03GiB path /dev/drbd2
> >          devid    4 size 1.82TiB used 82.03GiB path /dev/sde
> >
> > GRMPF!
> 
> pls use 'btrfs fi show -m' and just ignore no option or -d if fs is 
> mounted, as -m reads from the kernel.

There is now a new behaviour: after the btrfs mount, I can see shortly the
wrong raw device /dev/sde and a few seconds later there is the correct
/dev/drbd3 :


root@toy02:/etc# umount /data
root@toy02:/etc# mount /data
root@toy02:/etc# btrfs filesystem show
Label: data  uuid: 411af13f-6cae-4f03-99dc-5941acb3135b
        Total devices 2 FS bytes used 109.56GiB
        devid    3 size 1.82TiB used 63.03GiB path /dev/drbd2
        devid    4 size 1.82TiB used 63.03GiB path /dev/sde

Btrfs v3.12
root@toy02:/etc# btrfs filesystem show
Label: data  uuid: 411af13f-6cae-4f03-99dc-5941acb3135b
        Total devices 2 FS bytes used 109.56GiB
        devid    3 size 1.82TiB used 63.03GiB path /dev/drbd2
        devid    4 size 1.82TiB used 63.03GiB path /dev/drbd3

Btrfs v3.12

root@toy02:/etc# btrfs filesystem show -m
Label: data  uuid: 411af13f-6cae-4f03-99dc-5941acb3135b
        Total devices 2 FS bytes used 109.56GiB
        devid    3 size 1.82TiB used 63.03GiB path /dev/drbd2
        devid    4 size 1.82TiB used 63.03GiB path /dev/drbd3

Btrfs v3.12


Still, the kernel sees 3 instead of (really) 2 HGST drives:

root@toy02:/etc# hdparm -I /dev/sdb | grep Number:
        Model Number:       HGST HUS724020ALA640
        Serial Number:      PN2134P5G2P2AX

root@toy02:/etc# hdparm -I /dev/sde | grep Number:
        Model Number:       HGST HUS724020ALA640
        Serial Number:      PN2134P5G2P2AX

root@toy02:/etc# hdparm -I /dev/sdd | grep Number:
        Model Number:       HGST HUS724020ALA640
        Serial Number:      PN2134P5G2P2XX

-- 
Ullrich Horlacher              Informationssysteme und Serverbetrieb
IZUS/TIK                       E-Mail: horlacher@rus.uni-stuttgart.de
Universitaet Stuttgart         Tel:    ++49-711-68565868
Allmandring 30a                Fax:    ++49-711-682357
70550 Stuttgart (Germany)      WWW:    http://www.tik.uni-stuttgart.de/
REF:<55CCC4AB.2080600@oracle.com>