Hello,
I''d appreciate your recommendation on this:
I have three hdd with 3TB each. I intend to use them as raid5 eventually.
currently I use them like this:
# mount|grep sd
/dev/sda1 on /mnt/Datenplatte type ext4
/dev/sdb1 on /mnt/BTRFS/Video type btrfs
/dev/sdb1 on /mnt/BTRFS/rsnapshot type btrfs
#df -h
/dev/sda1 2,7T 1,3T 1,3T 51% /mnt/Datenplatte
/dev/sdb1 5,5T 5,4T 93G 99% /mnt/BTRFS/Video
/dev/sdb1 5,5T 5,4T 93G 99% /mnt/BTRFS/rsnapshot
Now, what surprises me, and here I lack memory- is that sdb appears
twice.. I think, I created a raid1, but how can I find out?
#/usr/local/smarthome# ~/btrfs/btrfs-progs/btrfs fi show /dev/sdb1
Label: none uuid: 989306aa-d291-4752-8477-0baf94f8c42f
Total devices 2 FS bytes used 2.68TB
devid 2 size 2.73TB used 2.73TB path /dev/sdc1
devid 1 size 2.73TB used 2.73TB path /dev/sdb1
Now, I wanted to convert it to raid0, because I lack space and
redundancy is not important for the Videos and the Backup, but this fails:
~/btrfs/btrfs-progs/btrfs fi balance start -dconvert=raid0 /mnt/BTRFS/
ERROR: error during balancing ''/mnt/BTRFS/'' - Inappropriate
ioctl for device
dmesg does not help here.
Anyway: This gave me some time to think about this. In fact, as soon as
raid5 is stable, I want to have all three as a raid5. Will this be
possible with a balance command? If so: will this be possible as soon as
raid5 is stable, or will I have to wait longer?
What approach do you recommend?
Greetings,
Hendrik
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On Thu, Jun 13, 2013 at 11:09:00PM +0200, Hendrik Friedel wrote:> Hello, > > I''d appreciate your recommendation on this: > > I have three hdd with 3TB each. I intend to use them as raid5 eventually. > currently I use them like this: > > # mount|grep sd > /dev/sda1 on /mnt/Datenplatte type ext4 > /dev/sdb1 on /mnt/BTRFS/Video type btrfs > /dev/sdb1 on /mnt/BTRFS/rsnapshot type btrfs > > #df -h > /dev/sda1 2,7T 1,3T 1,3T 51% /mnt/Datenplatte > /dev/sdb1 5,5T 5,4T 93G 99% /mnt/BTRFS/Video > /dev/sdb1 5,5T 5,4T 93G 99% /mnt/BTRFS/rsnapshot > > Now, what surprises me, and here I lack memory- is that sdb appears > twice.. I think, I created a raid1, but how can I find out?Appearing twice in that list is more an indication that you have multiple subvolumes -- check the subvol= options in /etc/fstab> #/usr/local/smarthome# ~/btrfs/btrfs-progs/btrfs fi show /dev/sdb1 > Label: none uuid: 989306aa-d291-4752-8477-0baf94f8c42f > Total devices 2 FS bytes used 2.68TB > devid 2 size 2.73TB used 2.73TB path /dev/sdc1 > devid 1 size 2.73TB used 2.73TB path /dev/sdb1 > > Now, I wanted to convert it to raid0, because I lack space and > redundancy is not important for the Videos and the Backup, but this > fails: > ~/btrfs/btrfs-progs/btrfs fi balance start -dconvert=raid0 /mnt/BTRFS/ > ERROR: error during balancing ''/mnt/BTRFS/'' - Inappropriate ioctl for device/mnt/BTRFS isn''t a btrfs subvol, according to what you have listed above. It''s a subdirectory in /mnt which is contains two subdirs (Video and rsnapshot) which are used as mountpoints for subvolumes. Try running the above command with /mnt/BTRFS/Video instead (or rsnapshot -- it doesn''t matter which).> dmesg does not help here. > > Anyway: This gave me some time to think about this. In fact, as soon > as raid5 is stable, I want to have all three as a raid5. Will this > be possible with a balance command? If so: will this be possible as > soon as raid5 is stable, or will I have to wait longer?Yes, it''s possible to convert to RAID-5 right now -- although the code''s not settled down into its final form quite yet. Note that RAID-5 over two devices won''t give you any space benefits over RAID-1 over two devices. (Or any reliability benefits either). Hugo. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk == PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- "Are you the man who rules the Universe?" "Well, I --- try not to."
On Thu, Jun 13, 2013 at 3:21 PM, Hugo Mills <hugo@carfax.org.uk> wrote:> On Thu, Jun 13, 2013 at 11:09:00PM +0200, Hendrik Friedel wrote: >> Hello, >> >> I''d appreciate your recommendation on this: >> >> I have three hdd with 3TB each. I intend to use them as raid5 eventually. >> currently I use them like this: >> >> # mount|grep sd >> /dev/sda1 on /mnt/Datenplatte type ext4 >> /dev/sdb1 on /mnt/BTRFS/Video type btrfs >> /dev/sdb1 on /mnt/BTRFS/rsnapshot type btrfs >> >> #df -h >> /dev/sda1 2,7T 1,3T 1,3T 51% /mnt/Datenplatte >> /dev/sdb1 5,5T 5,4T 93G 99% /mnt/BTRFS/Video >> /dev/sdb1 5,5T 5,4T 93G 99% /mnt/BTRFS/rsnapshot >> >> Now, what surprises me, and here I lack memory- is that sdb appears >> twice.. I think, I created a raid1, but how can I find out? > > Appearing twice in that list is more an indication that you have > multiple subvolumes -- check the subvol= options in /etc/fstab > >> #/usr/local/smarthome# ~/btrfs/btrfs-progs/btrfs fi show /dev/sdb1 >> Label: none uuid: 989306aa-d291-4752-8477-0baf94f8c42f >> Total devices 2 FS bytes used 2.68TB >> devid 2 size 2.73TB used 2.73TB path /dev/sdc1 >> devid 1 size 2.73TB used 2.73TB path /dev/sdb1 >> >> Now, I wanted to convert it to raid0, because I lack space and >> redundancy is not important for the Videos and the Backup, but this >> fails: >> ~/btrfs/btrfs-progs/btrfs fi balance start -dconvert=raid0 /mnt/BTRFS/ >> ERROR: error during balancing ''/mnt/BTRFS/'' - Inappropriate ioctl for device > > /mnt/BTRFS isn''t a btrfs subvol, according to what you have listed > above. It''s a subdirectory in /mnt which is contains two subdirs > (Video and rsnapshot) which are used as mountpoints for subvolumes. > > Try running the above command with /mnt/BTRFS/Video instead (or > rsnapshot -- it doesn''t matter which). > >> dmesg does not help here. >> >> Anyway: This gave me some time to think about this. In fact, as soon >> as raid5 is stable, I want to have all three as a raid5. Will this >> be possible with a balance command? If so: will this be possible as >> soon as raid5 is stable, or will I have to wait longer? > > Yes, it''s possible to convert to RAID-5 right now -- although the > code''s not settled down into its final form quite yet. Note that > RAID-5 over two devices won''t give you any space benefits over RAID-1 > over two devices. (Or any reliability benefits either). > > Hugo. > > -- > === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ==> PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk > --- "Are you the man who rules the Universe?" "Well, I --- > try not to."Raid5 currently is only suitable for testing: it''s known and expected to break on power cuts, for instance. The parity logging stuff is waiting on the skip-list implementation you may have read about on lwn, otherwise the performance overhead wasn''t acceptable or some such. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html