btrfs filesystem resize <ID>:max not working

btrfs filesystem resize <ID>:max not working

[André-Sebastian Liebe]

Hey list,

I've got a problem with resizing a multi drive filesystem.
I had a 5 disk array of 4TB drives. Then I added a 5th (6TB) drive to
the array and replaced one of the 4TB ones with a 6TB drive. As you can
see in my `btrfs fi sh` output below, my newly added drive (ID=6) has
the expected size of 5.46TiB, but my replaced drive (ID=4) won't show up
as 6TB as expected. Neither a `btrfs fi res max /data/pool0` nor a
`btrfs fi res 4:max /data/pool0` had any effect.

Any suggestions how to reclaim the 2TB free space of drive 4?


Thanks in advance

André-Sebastian Liebe


> Kernel:Linux apc01 3.19.2-1-ARCH #1 SMP PREEMPT Wed Mar 18 16:21:02
CET 2015 x86_64 GNU/Linux
> btrfs-progs: btrfs-progs v3.19

My 6 drives used by the apc01_pool (none of them has a partition table)
Konsole output
> # hdparm -I /dev/sdb | grep "device size"           
>        device size with M = 1024*1024:     3815447 MBytes
>        device size with M = 1000*1000:     4000787 MBytes (4000 GB)
> # hdparm -I /dev/sdc | grep "device size"  
>        device size with M = 1024*1024:     3815447 MBytes
>        device size with M = 1000*1000:     4000787 MBytes (4000 GB)
> # hdparm -I /dev/sdd | grep "device size"  
>        device size with M = 1024*1024:     3815447 MBytes
>        device size with M = 1000*1000:     4000787 MBytes (4000 GB)
> # hdparm -I /dev/sde | grep "device size"  
>        device size with M = 1024*1024:     3815447 MBytes
>        device size with M = 1000*1000:     4000787 MBytes (4000 GB)
> # hdparm -I /dev/sdf | grep "device size"  
>        device size with M = 1024*1024:     5723166 MBytes
>        device size with M = 1000*1000:     6001175 MBytes (6001 GB)
> # hdparm -I /dev/sdg | grep "device size"  
>        device size with M = 1024*1024:     5723166 MBytes
>        device size with M = 1000*1000:     6001175 MBytes (6001 GB)


btrfs filesystem:
Konsole output
> # btrfs fi sh
> Label: 'apc01_pool0'  uuid: 066141c6-16ca-4a30-b55c-e606b90ad0fb
>        Total devices 6 FS bytes used 23.43TiB
>        devid    1 size 3.64TiB used 3.61TiB path /dev/sdd
>        devid    2 size 3.64TiB used 3.61TiB path /dev/sdc
>        devid    3 size 3.64TiB used 3.61TiB path /dev/sde
>        devid    4 size 3.64TiB used 3.61TiB path /dev/sdg
>        devid    5 size 3.64TiB used 3.61TiB path /dev/sdb
>        devid    6 size 5.46TiB used 5.43TiB path /dev/sdf

Re: btrfs filesystem resize <ID>:max not working

[Chris Murphy]

On Thu, Apr 9, 2015 at 10:03 AM, André-Sebastian Liebe <andre@lianse.eu> wrote:
> Hey list,
>
> I've got a problem with resizing a multi drive filesystem.
> I had a 5 disk array of 4TB drives. Then I added a 5th (6TB) drive to
> the array and replaced one of the 4TB ones with a 6TB drive.

You did device add, device delete, then fi resize? It should work but
it's better to use btrfs replace start for this sort of operation
since it does all of that in one step.

> As you can
> see in my `btrfs fi sh` output below, my newly added drive (ID=6) has
> the expected size of 5.46TiB, but my replaced drive (ID=4) won't show up
> as 6TB as expected. Neither a `btrfs fi res max /data/pool0` nor a
> `btrfs fi res 4:max /data/pool0` had any effect.
>
> Any suggestions how to reclaim the 2TB free space of drive 4?

Not sure, this has always worked for me in the past, online. You could
try unmounting and doing a btrfs dev scan, remounting, and then
retrying the command. There's nothing in dmesg? There should be
something there whether it succeeds or fails.


-- 
Chris Murphy

[solved] Re: btrfs filesystem resize <ID>:max not working

[André-Sebastian Liebe]

Hey all,


On 04/09/2015 09:49 PM, Chris Murphy wrote:
> On Thu, Apr 9, 2015 at 10:03 AM, André-Sebastian Liebe <andre@lianse.eu> wrote:
>> Hey list,
>>
>> I've got a problem with resizing a multi drive filesystem.
>> I had a 5 disk array of 4TB drives. Then I added a 5th (6TB) drive to
>> the array and replaced one of the 4TB ones with a 6TB drive.
> You did device add, device delete, then fi resize? It should work but
> it's better to use btrfs replace start for this sort of operation
> since it does all of that in one step.
I did a device replace.


>> As you can
>> see in my `btrfs fi sh` output below, my newly added drive (ID=6) has
>> the expected size of 5.46TiB, but my replaced drive (ID=4) won't show up
>> as 6TB as expected. Neither a `btrfs fi res max /data/pool0` nor a
>> `btrfs fi res 4:max /data/pool0` had any effect.
>>
>> Any suggestions how to reclaim the 2TB free space of drive 4?
> Not sure, this has always worked for me in the past, online. You could
> try unmounting and doing a btrfs dev scan, remounting, and then
> retrying the command. There's nothing in dmesg? There should be
> something there whether it succeeds or fails.
Okay, I did a scrub, unmounted it, scanned for devices, remounted it and
redid the resize for drive 4. This time I got a syslog entry showing the
start of the resize and  about 5 minutes later the command finished
without an error.

Konsole output
> Apr 10 08:58:39 apc01 kernel: BTRFS info (device sdd): resizing devid 4
> Apr 10 08:58:39 apc01 kernel: BTRFS: new size for /dev/sdg is
6001175126016

`btrfs fi sh` finally shows both of my 6TB drives

Konsole output
> # btrfs fi sh
> Label: 'apc01_pool0'  uuid: 066141c6-16ca-4a30-b55c-e606b90ad0fb
>        Total devices 6 FS bytes used 23.43TiB
>        devid    1 size 3.64TiB used 3.61TiB path /dev/sdd
>        devid    2 size 3.64TiB used 3.60TiB path /dev/sdc
>        devid    3 size 3.64TiB used 3.60TiB path /dev/sde
>        devid    4 size 5.46TiB used 3.60TiB path /dev/sdg
>        devid    5 size 3.64TiB used 3.61TiB path /dev/sdb
>        devid    6 size 5.46TiB used 5.43TiB path /dev/sdf



Thanks for the hint!

Cheers
André