Re: Another novice question & comment

On 12/27/2012 11:55 AM, Chris Murphy wrote:

On Dec 27, 2012, at 9:47 AM, Swâmi Petaramesh [off-list ref] wrote:

quoted

Le 27/12/2012 16:03, Hugo Mills a écrit :

quoted

   Right now, no, there isn't any way of telling which subvolume is
mounted at a given location.

Er... Check "subvol=" here...

root@tethys:/# mount | grep btrfs
/dev/mapper/VG1-BTR_POOL on / type btrfs
(rw,relatime,subvol=UBUNTU/@,autodefrag,compress=lzo)
/dev/mapper/VG1-BTR_POOL on /tmp type btrfs
(rw,relatime,subvol=UBUNTU/@tmp,compress=lzo)
/dev/sda2 on /boot type btrfs (rw,relatime,subvol=UBUNTU/@boot,autodefrag)
/dev/mapper/VG1-BTR_POOL on /home type btrfs
(rw,relatime,subvol=UBUNTU/@home,autodefrag,compress=lzo)
/dev/mapper/VG1-BTR_POOL on /storage type btrfs
(rw,relatime,subvol=STORAGE,autodefrag,compress=lzo)
/dev/mapper/VG1-BTR_POOL on /data/BIG type btrfs
(rw,noatime,subvol=DATA/BIG,compress=lzo)

That would only seem to work with btrfs on LVM which I'd think is uncommon and complicated.

Oh thanks for that little reminder that you can put btrfs on an LV.

I am trying to see if I can get grub2 and os-prober to handle btrfs.  
There are a couple of patches out there but they do little if anything.  
The btrfs volumes and subvolumes are "not your father's filesystem" 8-)

I have a little of what is needed working but, the more I look at 
things, the more it looks like some real kludgy hack is going to be 
needed to have something which works with /dev/<whatever> to now use 
UUID=xxx,subvol=name

Gene