* understanding btrfs fi df
@ 2015-08-16 14:33 Hendrik Friedel
2015-08-16 14:57 ` Hugo Mills
0 siblings, 1 reply; 6+ messages in thread
From: Hendrik Friedel @ 2015-08-16 14:33 UTC (permalink / raw)
To: Btrfs BTRFS
Hello,
I am struggling to understand the output of btrfs fi df:
btrfs fi df /mnt/__Complete_Disk/
Data, RAID5: total=3.85TiB, used=3.85TiB
System, RAID5: total=32.00MiB, used=576.00KiB
Metadata, RAID5: total=6.46GiB, used=5.14GiB
GlobalReserve, single: total=512.00MiB, used=0.00B
I have three disks:
btrfs fi show
Label: none uuid: a8af3832-48c7-4568-861f-e80380dd7e0b
Total devices 3 FS bytes used 3.85TiB
devid 1 size 2.73TiB used 2.73TiB path /dev/sdf
devid 2 size 2.73TiB used 2.24TiB path /dev/sdd
devid 3 size 2.73TiB used 2.73TiB path /dev/sde
So I would expect around 5.4TiB to be available. In fact I am currently
using 4.4TiB and the drive seems to be full (I cannot store more data).
I went through Marcs Blog post on this, but the hints there did not
help. In particular:
btrfs balance start -dusage=95 /mnt/__Complete_Disk/ (started with 55)
What's wrong here?
Regards,
Hendrik
---
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: understanding btrfs fi df 2015-08-16 14:33 understanding btrfs fi df Hendrik Friedel @ 2015-08-16 14:57 ` Hugo Mills 2015-08-19 16:10 ` Hendrik Friedel 0 siblings, 1 reply; 6+ messages in thread From: Hugo Mills @ 2015-08-16 14:57 UTC (permalink / raw) To: Hendrik Friedel; +Cc: Btrfs BTRFS [-- Attachment #1: Type: text/plain, Size: 2734 bytes --] On Sun, Aug 16, 2015 at 04:33:52PM +0200, Hendrik Friedel wrote: > Hello, > > I am struggling to understand the output of btrfs fi df: > > btrfs fi df /mnt/__Complete_Disk/ > Data, RAID5: total=3.85TiB, used=3.85TiB > System, RAID5: total=32.00MiB, used=576.00KiB > Metadata, RAID5: total=6.46GiB, used=5.14GiB > GlobalReserve, single: total=512.00MiB, used=0.00B > > I have three disks: > > btrfs fi show > Label: none uuid: a8af3832-48c7-4568-861f-e80380dd7e0b > Total devices 3 FS bytes used 3.85TiB > devid 1 size 2.73TiB used 2.73TiB path /dev/sdf > devid 2 size 2.73TiB used 2.24TiB path /dev/sdd > devid 3 size 2.73TiB used 2.73TiB path /dev/sde Here's your problem -- you've got a RAID 5 filesystem, which has a minimum allocation of 2 devices, but only one device has free space on it for allocation, so no more chunks can be allocated. I'm not sure how it ended up in this situation, but that's what's happened. From btrfs fi df, you've filled up all the existing data allocation, so the usual filtered balance isn't going to help, because there's no space within the existing allocation to compact the storage into. You will need to free up some space on devices 1 and 3, and then run a full balance. There are two ways I can see of doing this: 1) add a small (4-8 GiB, say) block device, do a full balance, and then delete the device again: # btrfs dev add /dev/sdx /mnt/__Complete_Disk # btrfs balance start /mnt/__Complete_Disk # btrfs dev del /dev/sdx /mnt/__Complete_Disk 2) convert a few chunks of the existing FS, on devices 1 and 3, to single, which should free up some space across all the devices, and then run a full balance, and finally convert the single back to RAID 5: # btrfs balance start -dconvert=single,devid=1,limit=4 /mnt/__Complete_Disk # btrfs balance start -dconvert=single,devid=3,limit=4 /mnt/__Complete_Disk # btrfs balance start -dprofiles=raid5 /mnt/__Complete_Disk # btrfs balance start -dconvert=raid5,soft /mnt/__Complete_Disk Hugo. > So I would expect around 5.4TiB to be available. In fact I am > currently using 4.4TiB and the drive seems to be full (I cannot > store more data). > > I went through Marcs Blog post on this, but the hints there did not > help. In particular: > btrfs balance start -dusage=95 /mnt/__Complete_Disk/ (started with 55) > > What's wrong here? > > Regards, > Hendrik > > --- > Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. > https://www.avast.com/antivirus > -- Hugo Mills | ©1973 Unclear Research Ltd hugo@... carfax.org.uk | http://carfax.org.uk/ | PGP: E2AB1DE4 | [-- Attachment #2: Digital signature --] [-- Type: application/pgp-signature, Size: 836 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: understanding btrfs fi df 2015-08-16 14:57 ` Hugo Mills @ 2015-08-19 16:10 ` Hendrik Friedel 2015-08-19 16:17 ` Hugo Mills 0 siblings, 1 reply; 6+ messages in thread From: Hendrik Friedel @ 2015-08-19 16:10 UTC (permalink / raw) To: Hugo Mills, Btrfs BTRFS Hello Hugo, thanks for your hint. On 16.08.2015 16:57, Hugo Mills wrote: > Here's your problem -- you've got a RAID 5 filesystem, which has a > minimum allocation of 2 devices, but only one device has free space on > it for allocation, so no more chunks can be allocated. I'm not sure > how it ended up in this situation, but that's what's happened. > > 2) convert a few chunks of the existing FS, on devices 1 and 3, to > single, which should free up some space across all the devices, and > then run a full balance, and finally convert the single back to RAID > 5: > > # btrfs balance start -dconvert=single,devid=1,limit=4/mnt/__Complete_Disk > # btrfs balance start -dconvert=single,devid=3,limit=4/mnt/__Complete_Disk > # btrfs balance start -dprofiles=raid5/mnt/__Complete_Disk > # btrfs balance start -dconvert=raid5,soft/mnt/__Complete_Disk I did that. In order to run the first two commands I had to free some space though, which was no problem. Now the output is: root@homeserver:/media# btrfs fi df /mnt/__Complete_Disk Data, RAID5: total=3.79TiB, used=3.78TiB System, RAID5: total=32.00MiB, used=416.00KiB Metadata, RAID5: total=6.46GiB, used=4.85GiB GlobalReserve, single: total=512.00MiB, used=0.00B root@homeserver:/media# btrfs fi show Label: none uuid: a8af3832-48c7-4568-861f-e80380dd7e0b Total devices 3 FS bytes used 3.79TiB devid 1 size 2.73TiB used 2.43TiB path /dev/sdf devid 2 size 2.73TiB used 2.43TiB path /dev/sdd devid 3 size 2.73TiB used 1.38TiB path /dev/sde How can only 1.38TiB be used on devid 3? Greetings, Hendrik -- Hendrik Friedel Auf dem Brink 12 28844 Weyhe Tel. 04203 8394854 Mobil 0178 1874363 --- Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. https://www.avast.com/antivirus ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: understanding btrfs fi df 2015-08-19 16:10 ` Hendrik Friedel @ 2015-08-19 16:17 ` Hugo Mills 2015-08-19 17:37 ` Hendrik Friedel 0 siblings, 1 reply; 6+ messages in thread From: Hugo Mills @ 2015-08-19 16:17 UTC (permalink / raw) To: Hendrik Friedel; +Cc: Btrfs BTRFS [-- Attachment #1: Type: text/plain, Size: 2196 bytes --] On Wed, Aug 19, 2015 at 06:10:06PM +0200, Hendrik Friedel wrote: > Hello Hugo, > > thanks for your hint. > > On 16.08.2015 16:57, Hugo Mills wrote: > > Here's your problem -- you've got a RAID 5 filesystem, which has a > >minimum allocation of 2 devices, but only one device has free space on > >it for allocation, so no more chunks can be allocated. I'm not sure > >how it ended up in this situation, but that's what's happened. > > > >2) convert a few chunks of the existing FS, on devices 1 and 3, to > >single, which should free up some space across all the devices, and > >then run a full balance, and finally convert the single back to RAID > >5: > > > ># btrfs balance start -dconvert=single,devid=1,limit=4/mnt/__Complete_Disk > ># btrfs balance start -dconvert=single,devid=3,limit=4/mnt/__Complete_Disk > ># btrfs balance start -dprofiles=raid5/mnt/__Complete_Disk > ># btrfs balance start -dconvert=raid5,soft/mnt/__Complete_Disk > > > I did that. In order to run the first two commands I had to free > some space though, which was no problem. > > Now the output is: > root@homeserver:/media# btrfs fi df /mnt/__Complete_Disk > > Data, RAID5: total=3.79TiB, used=3.78TiB > System, RAID5: total=32.00MiB, used=416.00KiB > Metadata, RAID5: total=6.46GiB, used=4.85GiB > GlobalReserve, single: total=512.00MiB, used=0.00B > > root@homeserver:/media# btrfs fi show > Label: none uuid: a8af3832-48c7-4568-861f-e80380dd7e0b > Total devices 3 FS bytes used 3.79TiB > devid 1 size 2.73TiB used 2.43TiB path /dev/sdf > devid 2 size 2.73TiB used 2.43TiB path /dev/sdd > devid 3 size 2.73TiB used 1.38TiB path /dev/sde > > How can only 1.38TiB be used on devid 3? It shouldn't happen, as I understand how the process works. Can you show the output of "btrfs fi df /mnt/__Complete_Disk"? Let's just check that everything is indeed RAID-5 still. After this, we're probably going to have to look at the device and chunk trees to work out what's going on. Hugo. -- Hugo Mills | "I lost my leg in 1942. Some bastard stole it in a hugo@... carfax.org.uk | pub in Pimlico." http://carfax.org.uk/ | PGP: E2AB1DE4 | [-- Attachment #2: Digital signature --] [-- Type: application/pgp-signature, Size: 836 bytes --] ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: understanding btrfs fi df 2015-08-19 16:17 ` Hugo Mills @ 2015-08-19 17:37 ` Hendrik Friedel 2015-08-21 22:45 ` Hendrik Friedel 0 siblings, 1 reply; 6+ messages in thread From: Hendrik Friedel @ 2015-08-19 17:37 UTC (permalink / raw) To: Hugo Mills, Btrfs BTRFS Hi Hugo, thanks for your help. >> Now the output is: >> root@homeserver:/media# btrfs fi df /mnt/__Complete_Disk >> >> Data, RAID5: total=3.79TiB, used=3.78TiB >> System, RAID5: total=32.00MiB, used=416.00KiB >> Metadata, RAID5: total=6.46GiB, used=4.85GiB >> GlobalReserve, single: total=512.00MiB, used=0.00B >> >> root@homeserver:/media# btrfs fi show >> Label: none uuid: a8af3832-48c7-4568-861f-e80380dd7e0b >> Total devices 3 FS bytes used 3.79TiB >> devid 1 size 2.73TiB used 2.43TiB path /dev/sdf >> devid 2 size 2.73TiB used 2.43TiB path /dev/sdd >> devid 3 size 2.73TiB used 1.38TiB path /dev/sde >> >> How can only 1.38TiB be used on devid 3? > > It shouldn't happen, as I understand how the process works. Can you > show the output of "btrfs fi df /mnt/__Complete_Disk"? Let's just > check that everything is indeed RAID-5 still. Here we go: btrfs fi df /mnt/__Complete_Disk Data, RAID5: total=3.79TiB, used=3.78TiB System, RAID5: total=32.00MiB, used=416.00KiB Metadata, RAID5: total=6.46GiB, used=4.85GiB GlobalReserve, single: total=512.00MiB, used=0.00B Greetings, Hendrik Greetings, Hendrik -- Hendrik Friedel Auf dem Brink 12 28844 Weyhe Tel. 04203 8394854 Mobil 0178 1874363 --- Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. https://www.avast.com/antivirus ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: understanding btrfs fi df 2015-08-19 17:37 ` Hendrik Friedel @ 2015-08-21 22:45 ` Hendrik Friedel 0 siblings, 0 replies; 6+ messages in thread From: Hendrik Friedel @ 2015-08-21 22:45 UTC (permalink / raw) To: Hugo Mills, Btrfs BTRFS Hello Hugo, >> It shouldn't happen, as I understand how the process works. Can you >> show the output of "btrfs fi df /mnt/__Complete_Disk"? Let's just >> check that everything is indeed RAID-5 still. > > Here we go: > > btrfs fi df /mnt/__Complete_Disk > > Data, RAID5: total=3.79TiB, used=3.78TiB > System, RAID5: total=32.00MiB, used=416.00KiB > Metadata, RAID5: total=6.46GiB, used=4.85GiB > GlobalReserve, single: total=512.00MiB, used=0.00B can you help me on this? As far as I see, it's all Raid5. So, >> After this, we're probably going to have to look at the device and >> chunk trees to work out what's going on. Can you help me on this? Regards, Hendrik --- Diese E-Mail wurde von Avast Antivirus-Software auf Viren geprüft. https://www.avast.com/antivirus ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2015-08-21 22:45 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2015-08-16 14:33 understanding btrfs fi df Hendrik Friedel 2015-08-16 14:57 ` Hugo Mills 2015-08-19 16:10 ` Hendrik Friedel 2015-08-19 16:17 ` Hugo Mills 2015-08-19 17:37 ` Hendrik Friedel 2015-08-21 22:45 ` Hendrik Friedel
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