On 05/06/13 16:43, Hugo Mills wrote: > On Wed, Jun 05, 2013 at 04:28:33PM +0100, Martin wrote: >> On 05/06/13 16:05, Hugo Mills wrote: >>> On Wed, Jun 05, 2013 at 03:57:42PM +0100, Martin wrote: >>>> Dear Devs, >>>> >>>> I have x4 4TB HDDs formatted with: >>>> >>>> mkfs.btrfs -L bu-16TB_0 -d raid1 -m raid1 /dev/sd[cdef] >>>> >>>> >>>> /etc/fstab mounts with the options: >>>> >>>> noatime,noauto,space_cache,inode_cache >>>> >>>> >>>> All on kernel 3.8.13. >>>> >>>> >>>> Upon using rsync to copy some heavily hardlinked backups >>>> from ReiserFS, I've seen: >>>> >>>> >>>> The following "block rsv returned -28" is repeated 7 times >>>> until there is a call trace for: >>> >>> This is ENOSPC. Can you post the output of "btrfs fi df >>> /mountpoint" and "btrfs fi show", please? >> >> >> btrfs fi df: >> >> Data, RAID1: total=2.85TB, used=2.84TB Data: total=8.00MB, >> used=0.00 System, RAID1: total=8.00MB, used=412.00KB System: >> total=4.00MB, used=0.00 Metadata, RAID1: total=27.00GB, >> used=25.82GB Metadata: total=8.00MB, used=0.00 >> >> >> btrfs fi show: >> >> Label: 'bu-16TB_0' uuid: 8fd9a0a8-9109-46db-8da0-396d9c6bc8e9 >> Total devices 4 FS bytes used 2.87TB devid 4 size 3.64TB used >> 1.44TB path /dev/sdf devid 3 size 3.64TB used 1.44TB path >> /dev/sde devid 1 size 3.64TB used 1.44TB path /dev/sdc devid >> 2 size 3.64TB used 1.44TB path /dev/sdd > > OK, so you've got plenty of space to allocate. There were some > issues in this area (block reserves and ENOSPC, and I think > specifically addressing the issue of ENOSPC when there's space > available to allocate) that were fixed between 3.8 and 3.9 (and > probably some between 3.9 and 3.10-rc as well), so upgrading your > kernel _may_ help here. > > Something else that may possibly help as a sticking-plaster is to > write metadata more slowly, so that you don't have quite so much of > it waiting to be written out for the next transaction. Practically, > this may involve things like running "sync" on a loop. But it's > definitely a horrible hack that may help if you're desperate for a > quick fix until you can finish creating metadata so quickly and > upgrade your kernel... > > Hugo.
Thanks for that. I can give kernel 3.9.4 a try. For a giggle, I'll try first with "nice 19" and syncs in a loop... One confusing bit is why the "Data, RAID1: total=2.85TB" from "btrfs fi df"? Thanks, Martin -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
