Mailinglist Archive: opensuse-factory (776 mails)

[Jeff Mahoney <jeffm@xxxxxxxx>]

On 9/11/13 6:16 AM, Dirk Müller wrote:
> Hi Matthias,
>
> > Besides Scalability there are other attributes where
> > btrfs exceeds other filesystems.
>
> Regarding the scalability part, lets not compare something from 3
> years ago, lets compare the 13.1 kernel, kernel 3.11.0. Ext4 has had
> pretty nice improvements in 3.11 regarding scalability, see
> http://lkml.indiana.edu/hypermail/linux/kernel/1307.0/00286.html for
> details.
>
> http://www.phoronix.com/scan.php?page=article&item=linux_311_filesystems
>
> You might or not like this benchmark, but the headline is pretty
> clear: "EXT4 wins".
>
> Also, did btrfs fix the backlink issue? that seems to be a major
> scalability burden actually.

Again, yes:

commit f186373fef005cee948a4a39e6a14c2e5f517298
Author: Mark Fasheh <mfasheh@xxxxxxx>
Date:   Wed Aug 8 11:32:27 2012 -0700

    btrfs: extended inode refs

    This patch adds basic support for extended inode refs. This includes
support
    for link and unlink of the refs, which basically gets us support for
rename
    as well.

    Inode creation does not need changing - extended refs are only added
after
    the ref array is full.

    Signed-off-by: Mark Fasheh <mfasheh@xxxxxxx>

The current issue is the ability to enable them online. I have patches
to do that posted to the btrfs mailing list.

-Jeff


> And just to compare the _scalability_ we're talking about. the corner cases 
> are:
>
> BTRFS supports filesytems up to 16384 Petabytes. Ext4 has a slight
> disadvantage here, only spporting filesystems up to 1024 Petabytes.
> While that sounds like a serios scalability issue for SLE, it is less
> of a concern for the typical openSUSE case.
>
> Other scalability marks are not that interesting. But if we care about
> scalability and SSD support, F2FS might be interesting to look at as
> well..
>
>
> Greetings,
> Dirk


-- 
Jeff Mahoney
SUSE Labs