Ubuntu
btrfs-tools package

"btrfs filesystem show" shows wrong device

Bug #1477858 reported by Ulli Horlacher
6
This bug affects 1 person
Affects Status Importance Assigned to Milestone
btrfs-tools (Ubuntu)
New
Undecided
Unassigned

Bug Description

I have created a RAID0 btrfs filesystem with:

root@toy02:~# mkfs.btrfs /dev/drbd2 /dev/drbd3
root@toy02:~# mount /dev/drbd2 /mnt/new

btrfs shows wrong (raw) device /dev/sdb instead of /dev/drbd2 :

root@toy02:~# df -T /mnt/new
Filesystem Type 1K-blocks Used Available Use% Mounted on
/dev/drbd2 btrfs 3906909856 9136960 3895627648 1% /mnt/new

root@toy02:~# btrfs filesystem show /mnt/new
Label: none uuid: 586a32eb-fd15-4829-a4bf-c72c6d2f9074
        Total devices 2 FS bytes used 8.70GiB
        devid 1 size 1.82TiB used 6.03GiB path /dev/sdb
        devid 2 size 1.82TiB used 6.03GiB path /dev/drbd3

Btrfs v3.12

root@toy02:~# lf sdb /dev
lRWX - 2015-07-24 09:07 /dev/block/8:16 -> ../sdb
lRWX - 2015-07-24 09:07 /dev/disk/by-id/ata-HGST_HUS724020ALA640_PN2134P5G2P2AX -> ../../sdb
lRWX - 2015-07-24 09:07 /dev/disk/by-id/wwn-0x5000cca24ec137db -> ../../sdb
lRWX - 2015-07-24 09:07 /dev/disk/by-path/pci-0000:08:00.0-sas-0x1221000002000000-lun-0 -> ../../sdb
lRWX - 2015-07-24 09:07 /dev/disk/by-uuid/586a32eb-fd15-4829-a4bf-c72c6d2f9074 -> ../../sdb
bRW- 008,016 2015-07-24 09:07 /dev/sdb

root@toy02:~# lf drbd2 /dev
lRWX - 2015-07-23 18:50 /dev/block/147:2 -> ../drbd2
lRWX - 2015-07-23 18:50 /dev/drbd/by-disk/disk/by-id/ata-HGST_HUS724020ALA640_PN2134P5G2P2AX -> ../../../../drbd2
lRWX - 2015-07-23 18:50 /dev/drbd/by-res/data_new/0 -> ../../../drbd2
bRW- 147,002 2015-07-23 18:50 /dev/drbd2

root@toy02:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 14.04.2 LTS
Release: 14.04
Codename: trusty

root@toy02:~# dpkg -l | grep btrfs-tools
ii btrfs-tools 3.12-1 amd64 Checksumming Copy on Write Filesystem utilities

root@toy02:~# apt-cache policy btrfs-tools
btrfs-tools:
  Installed: 3.12-1
  Candidate: 3.12-1
  Version table:
 *** 3.12-1 0
        500 http://archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages
        100 /var/lib/dpkg/status

Revision history for this message
Ulli Horlacher (framstag) wrote :
Download full text (3.5 KiB)

Meanwhile I think this is a more deeper Linux bug, because...

This server has (besides some Seagates) 2 Hitachi (HGST) SATA disks, but
Linux shows 3 of them with 2 with the same serial number:

root@toy02:~# lsblk -o NAME,SIZE,FSTYPE,LABEL,MOUNTPOINT
NAME SIZE FSTYPE LABEL MOUNTPOINT
sda 1.8T drbd
sdb 1.8T btrfs data
sdc 1.8T drbd
sdd 1.8T drbd
sde 1.8T drbd
sdf 68G
|-sdf1 14.9G ext4 /
|-sdf2 14.9G ext4
|-sdf3 14.9G swap swap [SWAP]
 `-sdf4 23.3G ext4 tmp /tmp
sr0 1024M
drbd0 1.8T btrfs data
drbd1 1.8T
drbd2 1.8T btrfs data
drbd3 1.8T btrfs data

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

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

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

This is why btrfs gets confused:

root@toy02:~# btrfs_info
/data :

Data, RAID0: total=108.00GiB, used=107.55GiB
System, RAID1: total=32.00MiB, used=16.00KiB
Metadata, RAID1: total=1.00GiB, used=139.59MiB

Label: data uuid: 411af13f-6cae-4f03-99dc-5941acb3135b
        Total devices 3 FS bytes used 107.68GiB
        devid 1 size 1.82TiB used 37.03GiB path /dev/drbd0
        devid 3 size 1.82TiB used 36.03GiB path /dev/drbd2
        devid 4 size 1.82TiB used 37.00GiB path /dev/sdb

/dev/sdb is WRONG, it should be /dev/drbd3, because I have expanded the
btrfs filesystem with:

root@toy02:~# btrfs device add -f /dev/drbd3 /data

More info:

root@toy02:~# lf drbd /dev
dRWX - 2015-08-10 14:17 /dev/drbd
lRWX - 2015-08-10 14:18 /dev/block/147:0 -> ../drbd0
lRWX - 2015-08-11 14:45 /dev/block/147:1 -> ../drbd1
lRWX - 2015-08-11 14:00 /dev/block/147:2 -> ../drbd2
lRWX - 2015-08-11 14:00 /dev/block/147:3 -> ../drbd3
lRWX - 2015-08-11 14:00 /dev/drbd/by-disk/disk/by-id/ata-HGST_HUS724020ALA640_PN2134P5G2P2AX -> ../../../../drbd3
lRWX - 2015-08-11 14:00 /dev/drbd/by-disk/disk/by-id/ata-HGST_HUS724020ALA640_PN2134P5G2P2XX -> ../../../../drbd2
lRWX - 2015-08-11 14:45 /dev/drbd/by-disk/disk/by-id/ata-ST2000DM001-1CH164_W241L86K -> ../../../../drbd1
lRWX - 2015-08-10 14:18 /dev/drbd/by-disk/disk/by-id/ata-ST2000DM001-1CH164_W241L88L -> ../../../../drbd0
lRWX - 2015-08-11 14:00 /dev/drbd/by-res/d2 -> ../../drbd2
lRWX - 2015-08-11 14:00 /dev/drbd/by-res/d3 -> ../../drbd3
lRWX - 2015-08-10 14:18 /dev/drbd/by-res/data/0 -> ../../../drbd0
lRWX - 2015-08-11 14:45 /dev/drbd/by-res/data/1 -> ../../../drbd1
bRW- 147,000 2015-08-10 14:18 /dev/drbd0
bRW- 147,001 2015-08-11 14:45 /dev/drbd1
bRW- 147,002 2015-08-11 14:00 /dev/drbd2
bRW- 147,003 2015-08-11 14:00 /dev/drbd3

root@toy02:~# lf HGST /dev
lRWX - 2015-08-11 16:41 /dev/disk/by-id/ata-HGST_HUS724020ALA640_PN2134P5G2P2AX -> ../../sdb
lRWX - 2015-08-10 16:45 /dev/disk/by-id/ata-HGST_HUS724020ALA640_PN2134P5G2P2XX -> ../../sdd
lRWX - 2015-08-11 14:00 /dev/drbd/by-disk/disk/by-id/ata-HGST_HUS724020ALA640_...

Read more...

Revision history for this message
Rolf Leggewie (r0lf) wrote :

Have you reported this to the kernel bug tracker?

Revision history for this message
Ulli Horlacher (framstag) wrote : Re: [Bug 1477858] Re: "btrfs filesystem show" shows wrong device

On Mon 2016-08-01 (16:58), Rolf Leggewie wrote:
> Have you reported this to the kernel bug tracker?
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1477858
>
> Title:
> "btrfs filesystem show" shows wrong device

Yes.

--
Ullrich Horlacher Server und Virtualisierung
Rechenzentrum TIK
Universitaet Stuttgart E-Mail: <email address hidden>
Allmandring 30a Tel: ++49-711-68565868
70569 Stuttgart (Germany) WWW: http://www.tik.uni-stuttgart.de/
REF:<email address hidden>

Revision history for this message
Rolf Leggewie (r0lf) wrote :

The bug tracker or the ML AKA http://www.spinics.net/lists/linux-btrfs/msg46038.html? Can you please provide the bugzilla number?

To post a comment you must log in.
This report contains Public information  
Everyone can see this information.
Subscribing...

Other bug subscribers

Remote bug watches

Bug watches keep track of this bug in other bug trackers.