On Thu, Jun 23, 2011 at 07:37:12PM +0200, Martin Steigerwald wrote: > Hi! > > Short summary: I suspect that rsync´ing files to a newly created BTRFS > partition with a subvolume *and* enabled space_cache triggers the error > mentioned in the subject line of this mail. I reported this also as: > > Bug 38112 - btrfs: failed to load free space cache for block group on > rsync´ing to space_cache BTRFS with subvolume > > https://bugzilla.kernel.org/show_bug.cgi?id=38112 > > I will add a reference to my post here to the bug report, so feel free to > use whatever suits you best to follow up. > > > This happened on a ThinkPad T520 with 3.0.0-rc3-amd64 Debian/GNU Linux > kernel. The issue happened on a 2.5 inch external eSATA/USB harddisk which > I changed to BTRFS. On the repoot after the rsync process was stalled the > unrelated non space cache using root filesystem did not mount anymore with > 3.0.0-rc3-amd64 and 2.6.39-2-amd64 kernel. But thankfully it did mount > with a 2.6.38 grml 2011 amd64 kernel and now work again. > > > Thus I did > > merkaba:~> mkfs.btrfs -L daten /dev/sdc2 > > WARNING! - Btrfs Btrfs v0.19 IS EXPERIMENTAL > WARNING! - see http://btrfs.wiki.kernel.org before using > > fs created label daten on /dev/sdc2 > nodesize 4096 leafsize 4096 sectorsize 4096 size 447.13GB > Btrfs Btrfs v0.19 > > merkaba:~> mount -o space_cache,compress=lzo /dev/sdc2 /mnt/amazon-daten > merkaba:~> dmesg | tail -3 > [137440.930038] device label daten devid 1 transid 7 /dev/sdc2 > [137440.930507] btrfs: enabling disk space caching > [137440.930518] btrfs: use lzo compression > > > Then I unmounted, added a fstab entry without space_cache option since I > read that once BTRFS created a space_cache it would use it anyway it is > mounted with clear_cache to clear the cache again. > > I created a sub volume for movies, cause I wanted to be able to not > snapshot the movie files: > > merkaba:~> btrfs subvolume create /mnt/amazon-daten/Filme > Create subvolume '/mnt/amazon-daten/Filme' > > I then did my rsync from the backup which BTW was a BTRFS with space_cache > as well - created today: > > merkaba:~> rsync -a -H --acls --xattrs --sparse /mnt/steigerwald-daten/ > /mnt/amazon-daten > > A short while after starting the rsync I got: >
I've just posted a patch for this, sorry about that I've fixed this before but there has been recent work in this area to make it more generic and we lost that particular fix. Thanks, Josef -- 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
