On Mar 12, 2014, at 7:11 PM, Patrick O'Callaghan <pocallaghan(a)gmail.com> wrote:
(Sorry for the subject line but it's the best I could come up
with)
I recently installed F20 on a new system with a 120GB SSD and 1TB hard
drive. I'm using the SSD for /, /boot, /var and swap, and the hard drive
for /home. I decided to live on the edge and partition /home as BTRFS.
All this was done from Anaconda with no subsequent changes except adding
a few labels.
This is what I find:
$ lsblk --fs
NAME FSTYPE LABEL UUID
MOUNTPOINT
sda
├─sda1 ext4 boot
6d5929d8-fd35-49e6-a8bf-aab5309dad77 /boot
├─sda2 btrfs fedora_pxeclient-arch-00000-undi-002001-d4-3d-7e-f4-1b-08
22fecad3-619d-4a9b-aace-35a2e4e04c49 /home
├─sda3 ext4 root
6a9a800c-309b-4b69-b269-884ad495e7b9 /
├─sda4
├─sda5 ext4 var
d5955869-af07-4d6e-b1b3-6ccb31208b41 /var
└─sda6 swap
1431e6d2-531e-46cd-8633-1cf878c6b2a1 [SWAP]
sdb
└─sdb1 btrfs fedora_pxeclient-arch-00000-undi-002001-d4-3d-7e-f4-1b-08
22fecad3-619d-4a9b-aace-35a2e4e04c49
Note that /dev/sda2 and /dev/sdb1 have the same UUID and label.
I think you've stumbled into a bug. Since Btrfs directly supports multiple devices,
it's like LVM or raid in this respect, and for LVM and RAID, anaconda might be eager
to configure multiple device layouts this way.
So I'm going to bet dollars to donuts this is a Btrfs raid0 volume. What do you get
for
btrfs fi df /home #this is short for btrfs filesystem df /home
$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 68G 8.5G 56G 14% /
devtmpfs 7.8G 0 7.8G 0% /dev
tmpfs 7.9G 5.6M 7.8G 1% /dev/shm
tmpfs 7.9G 1.1M 7.9G 1% /run
tmpfs 7.9G 0 7.9G 0% /sys/fs/cgroup
tmpfs 7.9G 72K 7.9G 1% /tmp
/dev/sda1 477M 113M 335M 26% /boot
/dev/sda5 27G 1.8G 24G 7% /var
/dev/sda2 932G 73G 858G 8% /home
Note that /dev/sda2 is mounted and /dev/sdb1 is not. However /dev/sda2
has around 1TB of space, so it's clearly the hard drive.
Yeah the multiple device mounting behavior is different. You can mount either device and
the entire volume is thus mounted, you don't have to be explicit as btrfs finds its
other parts and uses them; it only complains when it can't find them.
What's going on, and should I be worried?
Well, it's raid0 so yeah I'd make a backup of anything important. It is possible
to do an online conversion to a single device layout, but depending on what you have in
/home it might actually be easier to back it up, blow away the current btrfs partitions,
and redo the mkfs on just sdb1, add the new UUID to your fstab, mount the new /home and
restore from backup. But I leave that up to you. The conversion is straight forward and it
should work, I've done it a bunch of times but you know… "yay btrfs with crossed
fingers".
Also, how can I change the label of the BTRFS partition? I used the
"btrfs filesystem label ..." command but although it registers the
change, the existing fedora_pxeclient.... label still shows up
in /dev/disk/by-label.
What do you get for
btrfs fi show
And does the first line Label: match the new label or the old?
Chris Murphy