similar to: enquiry about defrag

Kernel 3.1-rc8 btrfs-progs-0.19 mount options: noatime,autodefrag (space_cache is enabled) There are snapshots present on the filesystem. When I do a btrfs fi defrag on a file, the file becomes much more fragmented. The end result can be a file with 20k times more fragments than before. Initially I thought the extents were just smaller but were next to each other, so I checked with both

Hi list, I have a few large image files (VMware workstation VMDKs and TrueCrypt containers) which I routinely back up over the network to a btrfs raid10 volume via bigsync (https://code.google.com/p/bigsync/). The VM images in particular get really fragmented due to CoW, which is expected. I haven''t yet switched off CoW on the backups directory mainly to experiment and see what

Hi, I have 4 machines, all converted to BTRFS about 6 months ago, now all running Ubuntu Quantal with kernel 3.5.0-17 The matter is that all these machines are now getting slower and slower everyday, every disk access causing the disk to be 100% busy for long periods, to the point that I''m now seriously considering migrating everything back to ext4... From the start BTRFS was "not

While exploring some btrfs maintenance with respect to defragmenting I ran the following commands: # filefrag /path/to/34G.file /path/to/5.7G.file /path/to/34G.file: 2406 extents found /path/to/5.7G.file: 572 extents found Thinking those mostly static files could be less fragmented I ran: # btrfs filesystem defragment -c /path/to/34G.file # btrfs filesystem defragment -c /path/to/5.7G.file and

Hi! Today I converted my /home from Ext4 to BTRFS by reformatting and copying all over again. I created the filesystem with -l 16384 -n 16384 -d single -m single on an logical volume Intel SSD 320 and mount with compress=lzo,spacecache. Current state: merkaba:~> btrfs filesystem show failed to read /dev/sr0 Label: ''home'' uuid: […] Total devices 1 FS bytes used

We''re going to use this flag EXTENT_DEFRAG to indicate which range belongs to defragment so that we can implement snapshow-aware defrag: We set the EXTENT_DEFRAG flag when dirtying the extents that need defragmented, so later on writeback thread can differentiate between normal writeback and writeback started by defragmentation. This patch is used for the latter one. Originally patch

Hi folks, I''m using Ubuntu 12.10 Quantal with # uname -r 3.5.0-24-generic And it seems I cannot defrag : # filefrag /boot/initrd.img-3.5.0-24-generic /boot/initrd.img-3.5.0-24-generic: 3 extents found # btrfs filesystem defrag /boot/initrd.img-3.5.0-24-generic # echo $? 20 # filefrag /boot/initrd.img-3.5.0-24-generic /boot/initrd.img-3.5.0-24-generic: 3 extents found Any clue

I set the C (NOCOW) and z (Not_Compressed) flags on a folder but the extent counts of files contained there keep increasing. Said files are large and frequently modified but not changing in size. This does not happen when the filesystem is mounted with nodatacow. I''m using this as a workaround since subvolumes can''t be mounted with different options simultaneously. ie. one with

Hi, I''ve been using btrfs for my root partition for about a month on archlinux and recently Ive started using the i3 window manager and starting X manually and I now boot to run level 3 (multi-user.target for systemd) and Ive noticed that booting archlinux on a btrfs root, there is a lot off hdd chatter after the login prompts are displayed, which doesnt happen with ext4 on root, so I

Someone recently posted the following statement midway down the page at http://forums.gentoo.org/viewtopic-t-305871-postdays-0-postorder-asc-highlight-ext3+ordered+data-start-25.html >You don't need to defragment ext2/ext3 because as you use the >filesystem file blocks and inodes are moved around and reallocated >to keep the data nearly contiguous. It's not perfect, but it

- Add incompat flag, otherwise btrfs-progs will report error when operating on btrfs filesystems mounted with lzo option. - Allow to turn on lzo compression for defrag operation: # btrfs filesystem defragment -c[zlib, lzo] <file> Note: "-c zlib" will fail, because that''s how getopt() works for optional arguments. Signed-off-by: Li Zefan

The reason the deadlock is that: Task Btrfs-cleaner umount() down_write(&s->s_umount) sync_filesystem() do auto-defragment and produce lots of dirty pages close_ctree() wait for the end of btrfs-cleaner start_transaction reserve space shrink_delalloc() writeback_inodes_sb_nr_if_idle()

What are the recommendations for running KVM images on BTRFS systems using kernel 3.4?  I saw older posts on the web complaining about poor performance, but I know a lot of work has gone into btrfs since then.  There also seemed to be the nocow option, but I didn''t find anything that said it actualy helped. Anybody have ideas? Thanks, Matt -- To unsubscribe from this list: send the line

Hi, I planned to boost my btrfs performance today. here some errors I met: my ''btrfs filesystem show'' result: ~ # btrfs filesystem show failed to read /dev/sr0 Label: none uuid: 9b9aa9d9-760e-445c-a0ab-68e102d9f02e Total devices 1 FS bytes used 36.59GB devid 1 size 49.52GB used 49.52GB path /dev/sda6 Label: none uuid: 559dec06-4fd0-47c1-97b8-cc4fa6153fa0

Provide for modification of the limit of compressed extent size utilizing mount-time configuration settings. The size of compressed extents was limited to 128K, which leads to fragmentation of the extents (although the extents themselves may still be located contiguously). This limit is put in place to ease the RAM required when spreading compression across several CPUs, and to make sure the

Hi, If i set strict allocate = yes in samba to speed up the transfer of a mssql database dump, then btrfs does not compress the file. I have tried it also by just copying a small file in Windows to the samba share and the same. I have tried btrfs mount options autodefrag and then btrfs fi defrag -c and the file still does not get compressed. I have tried kernels 3.6.11, 3.8 and 3.10.7 on FC16

Hello, I habe the problems described in here https://btrfs.wiki.kernel.org/index.php/Gotchas: Files with a lot of random writes can become heavily fragmented (10000+ extents) causing trashing on HDDs and excessive multi-second spikes of CPU load on systems with an SSD or large amount a RAM. On servers and workstations this affects databases and virtual machine images. The nodatacow mount option

After running ceph on XFS for some time, I decided to try btrfs again. Performance with the current "for-linux-min" branch and big metadata is much better. The only problem (?) I''m still seeing is a warning that seems to occur from time to time: [87703.784552] ------------[ cut here ]------------ [87703.789759] WARNING: at fs/btrfs/inode.c:2103

On Mon, Oct 11, 2010 at 6:46 PM, Calvin Walton <calvin.walton@gmail.com> wrote: > On Mon, 2010-10-11 at 03:30 +0300, Felipe Contreras wrote: >> I use btrfs on most of my volumes on my laptop, and I''ve always felt >> booting was very slow, but definitely sure is slow, is starting up >> Google Chrome: >> >> encrypted ext4: ~20s >> btrfs: ~2:11s

Hi, all, I got machines running continuously for long time, but then the underlying ext3 file systems becomes quite heavily fragmented (94% non-contiguous). We just don't have a chance to shutdown the machines since they are always busy.. I tried the defrag 0.70 version comes with e2fsprog package and standalone 0.73 packages, but neither help me since the defrag tool can not handle ext3.