* Replacing RAID-1 devices with larger disks
@ 2016-02-28 20:15 Christian Robottom Reis
2016-02-28 20:34 ` Christian Robottom Reis
2016-02-28 20:36 ` Hugo Mills
0 siblings, 2 replies; 3+ messages in thread
From: Christian Robottom Reis @ 2016-02-28 20:15 UTC (permalink / raw)
To: linux-btrfs
Hello there,
I'm running a btrfs RAID-1 on two 128GB SSDs that were getting kind
of full. I found two 256GB SSDs that I plan to use to replace the 128TB
versions.
I've managed to do the actual swap using a series of btrfs replace
commands with no special arguments, and the system is now live and
booting from the 256GB drives. However, I haven't actually noticed any
difference in btrfs fi show output, and usage looks weird. Has anyone
seen this before or have a clue as to who?
The relevant partition sizes are now (sdb is identical):
/dev/sda1 * 2048 83888127 41943040 83 Linux
/dev/sda3 92276736 427821055 167772160 83 Linux
Here's the show output:
Label: 'root' uuid: 670d1132-00dc-4511-a2f6-d28ce08b4d3a
Total devices 2 FS bytes used 9.33GiB
devid 1 size 13.97GiB used 11.78GiB path /dev/sda1
devid 2 size 13.97GiB used 11.78GiB path /dev/sdb1
Label: 'var' uuid: 815b3280-e90f-483a-b244-1d2dfe9b6e67
Total devices 2 FS bytes used 56.14GiB
devid 1 size 80.00GiB used 80.00GiB path /dev/sda3
devid 2 size 80.00GiB used 80.00GiB path /dev/sdb3
Those sizes have not changed over the resize; i.e. the original sda1/sdb1 pair
was 14GB and the sda3/sdb3 pair was 80GB, and after the replace, they haven't
changed.
And usage for / is now weird:
Overall:
Device size: 27.94GiB
Device allocated: 21.56GiB
Device unallocated: 6.38GiB
Device missing: 0.00B
Used: 18.66GiB
Free (estimated): 3.99GiB (min: 3.99GiB)
Data ratio: 2.00
Metadata ratio: 2.00
Global reserve: 208.00MiB (used: 0.00B)
Data,RAID1: Size:9.00GiB, Used:8.20GiB
/dev/sda1 9.00GiB
/dev/sdb1 9.00GiB
Metadata,RAID1: Size:1.75GiB, Used:1.13GiB
/dev/sda1 1.75GiB
/dev/sdb1 1.75GiB
System,RAID1: Size:32.00MiB, Used:16.00KiB
/dev/sda1 32.00MiB
/dev/sdb1 32.00MiB
Usage for /var also looks wrong, but in a different way:
Overall:
Device size: 160.00GiB
Device allocated: 160.00GiB
Device unallocated: 2.00MiB
Device missing: 0.00B
Used: 112.28GiB
Free (estimated): 21.20GiB (min: 21.20GiB)
Data ratio: 2.00
Metadata ratio: 2.00
Global reserve: 512.00MiB (used: 0.00B)
Data,RAID1: Size:74.97GiB, Used:53.77GiB
/dev/sda3 74.97GiB
/dev/sdb3 74.97GiB
Metadata,RAID1: Size:5.00GiB, Used:2.37GiB
/dev/sda3 5.00GiB
/dev/sdb3 5.00GiB
System,RAID1: Size:32.00MiB, Used:16.00KiB
/dev/sda3 32.00MiB
/dev/sdb3 32.00MiB
Unallocated:
/dev/sda3 1.00MiB
/dev/sdb3 1.00MiB
Version information:
async@riff:~$ uname -a
Linux riff 4.2.0-30-generic #36~14.04.1-Ubuntu SMP Fri Feb 26 18:49:23
UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
async@riff:~$ btrfs --version
btrfs-progs v4.0
Thanks,
--
Christian Robottom Reis | [+55 16] 3376 0125 | http://async.com.br/~kiko
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Replacing RAID-1 devices with larger disks
2016-02-28 20:15 Replacing RAID-1 devices with larger disks Christian Robottom Reis
@ 2016-02-28 20:34 ` Christian Robottom Reis
2016-02-28 20:36 ` Hugo Mills
1 sibling, 0 replies; 3+ messages in thread
From: Christian Robottom Reis @ 2016-02-28 20:34 UTC (permalink / raw)
To: linux-btrfs
On Sun, Feb 28, 2016 at 05:15:32PM -0300, Christian Robottom Reis wrote:
> I've managed to do the actual swap using a series of btrfs replace
> commands with no special arguments, and the system is now live and
> booting from the 256GB drives. However, I haven't actually noticed any
> difference in btrfs fi show output, and usage looks weird. Has anyone
> seen this before or have a clue as to who?
Yes, now I do, about 10 minutes after writing that mail. After a btrfs
replace, if the device being added is larger than the original device,
you need to issue:
btrfs fi resize <devid>:max <path>
to actually use that disk space. So for something like:
> Label: 'root' uuid: 670d1132-00dc-4511-a2f6-d28ce08b4d3a
> Total devices 2 FS bytes used 9.33GiB
> devid 1 size 13.97GiB used 11.78GiB path /dev/sda1
> devid 2 size 13.97GiB used 11.78GiB path /dev/sdb1
>
> Label: 'var' uuid: 815b3280-e90f-483a-b244-1d2dfe9b6e67
> Total devices 2 FS bytes used 56.14GiB
> devid 1 size 80.00GiB used 80.00GiB path /dev/sda3
> devid 2 size 80.00GiB used 80.00GiB path /dev/sdb3
You need to do:
btrfs fi resize 1:max /
btrfs fi resize 2:max /
btrfs fi resize 1:max /var
btrfs fi resize 2:max /var
And it looks great now:
Label: 'root' uuid: 670d1132-00dc-4511-a2f6-d28ce08b4d3a
Total devices 2 FS bytes used 9.34GiB
devid 1 size 40.00GiB used 10.78GiB path /dev/sda1
devid 2 size 40.00GiB used 10.78GiB path /dev/sdb1
Label: 'var' uuid: 815b3280-e90f-483a-b244-1d2dfe9b6e67
Total devices 2 FS bytes used 56.16GiB
devid 1 size 160.00GiB used 80.00GiB path /dev/sda3
devid 2 size 160.00GiB used 80.00GiB path /dev/sdb3
This would be nice to document in the manpage for replace; it would also
be a good addition to the best google hit for replace RAID-1:
http://unix.stackexchange.com/questions/227560/how-to-replace-a-device-in-btrfs-raid-1-filesystem
but I don't have enough reputation to do it myself.
--
Christian Robottom Reis | [+55 16] 3376 0125 | http://async.com.br/~kiko
| [+55 16] 991 126 430 | http://launchpad.net/~kiko
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: Replacing RAID-1 devices with larger disks
2016-02-28 20:15 Replacing RAID-1 devices with larger disks Christian Robottom Reis
2016-02-28 20:34 ` Christian Robottom Reis
@ 2016-02-28 20:36 ` Hugo Mills
1 sibling, 0 replies; 3+ messages in thread
From: Hugo Mills @ 2016-02-28 20:36 UTC (permalink / raw)
To: Christian Robottom Reis; +Cc: linux-btrfs
[-- Attachment #1: Type: text/plain, Size: 4032 bytes --]
On Sun, Feb 28, 2016 at 05:15:32PM -0300, Christian Robottom Reis wrote:
> Hello there,
>
> I'm running a btrfs RAID-1 on two 128GB SSDs that were getting kind
> of full. I found two 256GB SSDs that I plan to use to replace the 128TB
> versions.
>
> I've managed to do the actual swap using a series of btrfs replace
> commands with no special arguments, and the system is now live and
> booting from the 256GB drives. However, I haven't actually noticed any
> difference in btrfs fi show output, and usage looks weird. Has anyone
> seen this before or have a clue as to who?
Device replace doesn't change the amount of the device that the FS
will use -- Like most FSes, btrfs has its own concept of the amount of
a device it should use.
You probably need to run btrfs fi resize on the FS for each device:
# btrfs fi resize 1:max /mountpoint
# btrfs fi resize 2:max /mountpoint
Hugo.
> The relevant partition sizes are now (sdb is identical):
>
> /dev/sda1 * 2048 83888127 41943040 83 Linux
> /dev/sda3 92276736 427821055 167772160 83 Linux
>
> Here's the show output:
>
> Label: 'root' uuid: 670d1132-00dc-4511-a2f6-d28ce08b4d3a
> Total devices 2 FS bytes used 9.33GiB
> devid 1 size 13.97GiB used 11.78GiB path /dev/sda1
> devid 2 size 13.97GiB used 11.78GiB path /dev/sdb1
>
> Label: 'var' uuid: 815b3280-e90f-483a-b244-1d2dfe9b6e67
> Total devices 2 FS bytes used 56.14GiB
> devid 1 size 80.00GiB used 80.00GiB path /dev/sda3
> devid 2 size 80.00GiB used 80.00GiB path /dev/sdb3
>
> Those sizes have not changed over the resize; i.e. the original sda1/sdb1 pair
> was 14GB and the sda3/sdb3 pair was 80GB, and after the replace, they haven't
> changed.
>
> And usage for / is now weird:
>
> Overall:
> Device size: 27.94GiB
> Device allocated: 21.56GiB
> Device unallocated: 6.38GiB
> Device missing: 0.00B
> Used: 18.66GiB
> Free (estimated): 3.99GiB (min: 3.99GiB)
> Data ratio: 2.00
> Metadata ratio: 2.00
> Global reserve: 208.00MiB (used: 0.00B)
>
> Data,RAID1: Size:9.00GiB, Used:8.20GiB
> /dev/sda1 9.00GiB
> /dev/sdb1 9.00GiB
>
> Metadata,RAID1: Size:1.75GiB, Used:1.13GiB
> /dev/sda1 1.75GiB
> /dev/sdb1 1.75GiB
>
> System,RAID1: Size:32.00MiB, Used:16.00KiB
> /dev/sda1 32.00MiB
> /dev/sdb1 32.00MiB
>
> Usage for /var also looks wrong, but in a different way:
>
> Overall:
> Device size: 160.00GiB
> Device allocated: 160.00GiB
> Device unallocated: 2.00MiB
> Device missing: 0.00B
> Used: 112.28GiB
> Free (estimated): 21.20GiB (min: 21.20GiB)
> Data ratio: 2.00
> Metadata ratio: 2.00
> Global reserve: 512.00MiB (used: 0.00B)
>
> Data,RAID1: Size:74.97GiB, Used:53.77GiB
> /dev/sda3 74.97GiB
> /dev/sdb3 74.97GiB
>
> Metadata,RAID1: Size:5.00GiB, Used:2.37GiB
> /dev/sda3 5.00GiB
> /dev/sdb3 5.00GiB
>
> System,RAID1: Size:32.00MiB, Used:16.00KiB
> /dev/sda3 32.00MiB
> /dev/sdb3 32.00MiB
>
> Unallocated:
> /dev/sda3 1.00MiB
> /dev/sdb3 1.00MiB
>
>
> Version information:
>
> async@riff:~$ uname -a
> Linux riff 4.2.0-30-generic #36~14.04.1-Ubuntu SMP Fri Feb 26 18:49:23
> UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
>
> async@riff:~$ btrfs --version
> btrfs-progs v4.0
>
> Thanks,
--
Hugo Mills | You stay in the theatre because you're afraid of
hugo@... carfax.org.uk | having no money? There's irony...
http://carfax.org.uk/ |
PGP: E2AB1DE4 | Slings and Arrows
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 836 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2016-02-28 20:36 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-02-28 20:15 Replacing RAID-1 devices with larger disks Christian Robottom Reis
2016-02-28 20:34 ` Christian Robottom Reis
2016-02-28 20:36 ` Hugo Mills
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.