Arch Linux

alex.forencich

Member

Registered: 2011-05-29

Posts: 96

Partition UUID missing?

I have a large external hard drive with one gigantic btrfs partition on it.  It used to be enumerated correctly in /dev/disk/by-uuid and blkid, but right now I cannot mount it by uuid from /etc/fstab (preventing the computer from booting) and it does not show up in either /dev/disk/by-uuid or in blkid.  I can see the partition and I can mount it with /dev/sdb1 and it works correctly, so it seems like the parition is fine and the filesystem is fine.  After it is mounted, btrfs filesystem show does display the original uuid.  Any ideas on what might be going on here? 

[root@atomic ~]# blkid
/dev/sda1: LABEL="arch" UUID="2f874539-42d1-458c-b3a2-bce041fe08df" TYPE="ext4" PARTUUID="00005f60-01" 
/dev/sda2: LABEL="swap" UUID="05cb7ef4-91d9-4b96-90f0-aa29e1e21946" TYPE="swap" PARTUUID="00005f60-02" 
[root@atomic ~]# ls -al /dev/disk/by-uuid/
total 0
drwxr-xr-x 2 root root  80 Jan 14 23:41 .
drwxr-xr-x 5 root root 100 Jan 14 23:41 ..
lrwxrwxrwx 1 root root  10 Jan 14 23:41 05cb7ef4-91d9-4b96-90f0-aa29e1e21946 -> ../../sda2
lrwxrwxrwx 1 root root  10 Jan 14 23:41 2f874539-42d1-458c-b3a2-bce041fe08df -> ../../sda1
[root@atomic ~]# btrfs filesystem show
Label: qx2  uuid: 6d40af9b-ae3b-498b-97f3-4731e57438ca
        Total devices 1 FS bytes used 4.31TiB
        devid    1 size 5.46TiB used 5.46TiB path /dev/sdb1

Btrfs v3.12

Edit: lsblk doesn't work either:

[root@atomic ~]# lsblk -f
NAME   FSTYPE LABEL UUID                                 MOUNTPOINT
sda                                                      
|-sda1 ext4   arch  2f874539-42d1-458c-b3a2-bce041fe08df /
`-sda2 swap   swap  05cb7ef4-91d9-4b96-90f0-aa29e1e21946 [SWAP]
sdb                                                      
`-sdb1                                                   /srv/nfs4/qx2

Last edited by alex.forencich (2014-01-15 08:04:18)

x33a

Forum Fellow

Registered: 2009-08-15

Posts: 4,587

Re: Partition UUID missing?

Maybe it happened due to a recent update? See if you updated any package recently which could have caused this.

Also, post the output of

$ ls -lR /dev/disk/ 

when the drive is not mounted as well as when it is mounted.

alex.forencich

Member

Registered: 2011-05-29

Posts: 96

Re: Partition UUID missing?

Here it is; no difference mounted vs. unmounted:

[root@atomic ~]# ls -lR /dev/disk/
/dev/disk/:
total 0
drwxr-xr-x 2 root root 140 Jan 14 23:41 by-id
drwxr-xr-x 2 root root  80 Jan 14 23:41 by-label
drwxr-xr-x 2 root root  80 Jan 14 23:41 by-uuid

/dev/disk/by-id:
total 0
lrwxrwxrwx 1 root root  9 Jan 14 23:41 ata-WDC_WD2500YD-01NVB1_WD-WCANKJ464345 -> ../../sda
lrwxrwxrwx 1 root root 10 Jan 14 23:41 ata-WDC_WD2500YD-01NVB1_WD-WCANKJ464345-part1 -> ../../sda1
lrwxrwxrwx 1 root root 10 Jan 14 23:41 ata-WDC_WD2500YD-01NVB1_WD-WCANKJ464345-part2 -> ../../sda2
lrwxrwxrwx 1 root root  9 Jan 14 23:41 ata-eSATA-2_ExternalRAID_WD-WCAVY0496391 -> ../../sdb
lrwxrwxrwx 1 root root 10 Jan 14 23:41 ata-eSATA-2_ExternalRAID_WD-WCAVY0496391-part1 -> ../../sdb1

/dev/disk/by-label:
total 0
lrwxrwxrwx 1 root root 10 Jan 14 23:41 arch -> ../../sda1
lrwxrwxrwx 1 root root 10 Jan 14 23:41 swap -> ../../sda2

/dev/disk/by-uuid:
total 0
lrwxrwxrwx 1 root root 10 Jan 14 23:41 05cb7ef4-91d9-4b96-90f0-aa29e1e21946 -> ../../sda2
lrwxrwxrwx 1 root root 10 Jan 14 23:41 2f874539-42d1-458c-b3a2-bce041fe08df -> ../../sda1