similar to: Finding Fragmentation on a Btrfs Volume

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 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

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

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

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

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

In support of the recently added capability to remount with lzo compression, provide a helper function to check the compression INCOMPAT flags when remounting with lzo compression, and set the flags if necessary. Also, implement the new helper function when defragmenting with explicit lzo compression and when setting the default subvolume. Signed-off-by: Mitch Harder

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

Hello, Does anybody know how to avoid the file fragmentation when a file is created over NFSv3? A file created locally is OK: dd bs=32k if=/dev/zero of=test count=32x1024 conv=fsync filefrag test test: 10 extents found, perfection would be 9 extents When I create the file in the same dir, but from another machine, mounted over NFS: filefrag test test: 4833 extents found, perfection would be

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.

Hi Timo, Any chance the mbox/mdbox writer code could be modified to do physical preallocation on files to help avoid file(system) fragmentation? Constantly appending a file is the prime recipe for causing fragmentation, and mbox is notorious for this--not a fault of Dovecot but the nature of the mbox beast. Obviously maildir doesn't have such a problem, but some (many?) of us still prefer

Hi all, i am new on btrfs, i am testing KVM on btrfs (host: kernel x86-64 3.5.3), the performance is reasonable. I have two question on defrag, can someone help me? 1. According to btrfs wiki, defragment a COW file will produce two unrelated files. Does it apply to the "autodefrag" mount option? 2. Is there any command for the fragmentation status of a file/dir ? e.g. fragment

We''ve been hitting BUG()''s in btrfs_cont_expand and btrfs_fallocate and anywhere else that calls btrfs_get_extent while running xfstests 13 in a loop. This is because fiemap is calling btrfs_get_extent with non-sectorsize aligned offsets, which will end up adding mappings that are not sectorsize aligned, which will cause problems in some cases for subsequent calls to

Hi! Is there plans for fragmentation analyzing/reporting and online defragmentation tools for btrfs? And what about delayed allocation? Thanks!

Two files in the different subvolumes may have the same inode id, so The rb-tree which is used to manage the defragment object must take it into account. This patch fix this problem. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> --- fs/btrfs/file.c | 45 +++++++++++++++++++++++++++++++++++---------- 1 files changed, 35 insertions(+), 10 deletions(-) diff --git a/fs/btrfs/file.c

Let me preface this by saying "Yes, I know *nix filesystems don't need to worry about fragmentation". That said, is there a way to check the overall level of fragmentation of a live ext3 filesystem? I know about filefrag, but that's for specific files. And I think e2fsck tells you, but only if you take the filesystem offline for the scan. Is there anything that will give

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

A user has encountered a NULL pointer kernel oops in btrfs when encountering media errors. The problem has been identified as an unhandled NULL pointer returned from find_get_page(). This modification simply checks for a NULL page, and returns with an error if found (the extent_range_uptodate() function returns 1 on errors). After testing this patch, the user reported that the error with the

Introduce a new flag FIEMAP_FLAG_COW to fiemap ioctl(2) interface. If this flag is set, the kernel will only return the mapped extents which are in copy-on-write state. Signed-off-by: Jie Liu <jeff.liu at oracle.com> Cc: Alexander Viro <viro at zeniv.linux.org.uk> Cc: Andreas Dilger <adilger at dilger.ca> Cc: Dave Chinner <david at fromorbit.com> Cc: Mark Fasheh

Right now inode cache inode is treated as the same as space cache inode, ie. keep inode in memory till putting super. But this leads to an awkward situation. If we''re going to delete a snapshot/subvolume, btrfs will not actually delete it and return free space, but will add it to dead roots list until the last inode on this snap/subvol being destroyed. Then we''ll fetch deleted