Am Samstag, 17. Dezember 2011 schrieb Sergei Trofimovich: > On Fri, 16 Dec 2011 21:58:45 +0100 > > Martin Steigerwald <Martin@xxxxxxxxxxxx> wrote: > > Nope. Doesn´t seem to help much. > > > > How to turn it off, after turning it on? > > > > deepdance:~> LANG=C mount -o remount,datacow / > > mount: / not mounted already, or bad option > > In debian you can disable syncing on per-process basis: > http://packages.debian.org/sid/eatmydata > > $ eatmydata apt-get install foo > $ eatmydata firefox > $ eatmydata liferea > > makes things more bearable I am not ready to accept that this is the proper answer to what I experience. Applications using fsync() are realistic real world scenarios and I think BTRFS has to cope with that. Yesterday I upgraded the laptop to 3.2-rc4. After converting the inode cache the filesystem appeared to be faster, but I have to wait for some Debian packages to pile up on the repository servers to get a real impression. I think I will scrub / balance / defragment the filesystem after a backup. But I am not sure in what order. I understand that defragment defragments files. But then what does balance do? For RAID setup I have seen it distributing data evenly across drives when I echo > /sys/block/sda/[…]/delete a drive before and BTRFS had to distribute unevenly cause of that. But what does it do on a filesystem on a single drive? I bet it would balance out trees? Will it resize trees with lots of unused space as well? According to deepdance:~> btrfs filesystem df / Data: total=11.23GB, used=6.98GB System, DUP: total=8.00MB, used=4.00KB System: total=4.00MB, used=0.00 Metadata, DUP: total=1.86GB, used=511.35MB deepdance:~> btrfs filesystem show […] Label: 'debian' uuid: 2bf5b1dc-1d89-4f0d-a561-1a5551a27275 Total devices 1 FS bytes used 7.48GB devid 1 size 15.00GB used 14.97GB path /dev/dm-0 Btrfs Btrfs v0.19 the filesystem might have had some chances to fragment heavily, cause the tree sizes add up almost to the 15 GB of space available. I also remember that for some time the filesystem was nearly full which would explain the tree sizes. Ciao, -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
