ext4 online defrag status?

ext4 online defrag status?

[Tomasz Chmielewski]

I was wondering what is the status of online defragment for ext4?


Generally, fragmentation isn't a big problem with every day usage, but 
can bite when virtual machine (i.e. KVM) disk images are files.

For example:

vm-111-disk-1.raw: 28054 extents found, perfection would be 138 extents


There have been some ext4 defrag patches posted in 2008 and 2009 - what 
is the state of this now in late 2010?



-- 
Tomasz Chmielewski
http://wpkg.org

Re: ext4 online defrag status?

[Kazuya Mio]

Hi Tomasz,

2010/11/22 4:33, Tomasz Chmielewski wrote:
> There have been some ext4 defrag patches posted in 2008 and 2009 - what is the state of this now in late 2010?

Ext4 online defragment has been already merged into the kernel space.
However, e4defrag command has been stopped updating since August 2009,
although some bugfix patches were posted.
I don't know why not e4defrag command is updated, but Ted, the e2fsprogs
maintainer, previously said that e4defrag needs acid test.
https://bugs.launchpad.net/ubuntu/+bug/321528

I have been continuing to evaluate e4defrag command. If someone would help,
please test the newest e4defrag by the following steps:

1. Download e2fsprogs git tree
    # git pull http://git.kernel.org/pub/scm/fs/ext2/e2fsprogs.git

2. Apply the patch I sent a while ago
    http://marc.info/?l=linux-ext4&m=128272690010784&w=4

3. Apply the latest bugfix patch
    http://marc.info/?l=linux-ext4&m=129015317309425&w=4

Regards,
Kazuya Mio