Hi,
I decided to try btrfs with my suse. I install zen kernel 2.6.28-zen10 with btrfs support, btrfs-progs-0.18 from filesystems repo, made an another partition for new root with btrfs and copyed the whole filesystem from my original ext3 partition to it - everything worked just fine until this point.
I made the needed changes in fstab and grub.conf an new btrfs root, the kernel knows about btrfs, but when I boot, it still wants to mount as ext3 the btrfs root. I need the change the fs type somewhere else than in fstab, or what cold be the problem?
Thank you for help in anticipation and sorry for my bad english.
Even if it’s a little late by now… The problem is not your fstab, nor is it a wrong recognition. GRUB just doesn’t know about btrfs. Thus, you’ll need to wait until the code gets implemented into GRUB.
Till then GRUB will always be considered ext3
This is similar for ext4 without the appropriate GRUB modules. However, you can still make use of it already (even if one partition is NOT AT ALL what it’s intents are.)
This is my config:
/dev/sda1 * 1 51 409600 83 Linux
/dev/sda2 51 19174 153600000 8e Linux LVM
/dev/sda3 19174 30401 90186401 8e Linux LVM
sda2 contains a logical volume, so sda3.
On sda2 I have different partitions I want to share between different OSs (all configured as Volume Groups) This is for instance /opt /home /MyMedia and stuff like that. A local repo could be imaginable and desirable as well.
sda3 contains a swap space and actually my fedora installation. Got space left which I’m gonna assign to another sidux installation, as well as a suse installation. With btrfs now you could do sth like creating raid partitions, or join them together and mount them as one.
Or assign dynamically growing partitions which won’t use more diskspace than actually needed.
Plus you can fsck each partition while online (this is mounted as a part of your currently living OS), distribute file between partitions, create A LOT of realtime browsable and revertible snapshots (browsable => New Time Slider features coming up in OpenSolaris 2009.06 : Erwann Chénedé’s Weblog )
and a lot of other neat stuff.
As you can see above, I have ceated a ext3 partition sized 200MB (50Blocks*4096kb blocksize)
, this is where I installed GRUB and the MBR.
Everything else is chainloaded from there.
And the actual magic happens inside the logical volumes. This looks like this for instance: (the volume local holds the shares, opt and home in this case, the vol group tiffy is a swap space and fedora 11)
LV VG Attr #Str Type SSize
LogVol00 vg_local -wi-ao 1 linear 97.66G
LogVol01 vg_local -wi-ao 1 linear 25.39G
LogVol00 vg_tiffy -wi-ao 1 linear 19.60G
LogVol01 vg_tiffy -wi-ao 1 linear 1.95G
So, if you want to try it, bear in mind to create a rather small boot partition, and chainload from there.
You may ask dmesg if everything went fine:
dmesg | grep btrfs
docter~] dmesg | grep btrfs
Btrfs loaded
btrfs: disabling barriers on dev /dev/root
btrfs: disabling barriers on dev /dev/mapper/vg_local-LogVol00
btrfs: disabling barriers on dev /dev/mapper/vg_local-LogVol01
You could even plug external harddrives in, create a btrfs across all of them and rsync, reallocate, backup, raid or whatsoever with your files.