[Samba] filesystem of choice?

[Stan Hoeppner]

On 6/24/2011 5:31 PM, John Drescher wrote:
>>        I would use 'xfs'.  I believe samba was originally developed
>> over xfs, so it's likely the ea-suppot and acl support has had the most
>> testing there.  Especially if your file server is setup with a UPS, then I'd
>> strongly recommend it.   If not, ext4 might be safer (with write
>> through).   It will be slower, but safer.
>>
>>        With a UPS, XFS's default 'write-back', will give the fastest
>> performance for large file writes (I think reads as well).   It's worst
>> performance is on "removing" large numbers of files, as that is pretty
>> much a  synchronous operation...
> 
> I would just use ext4, it does not have the ext3 large file slowness
> or xfs slowdown with lots of small files.

"xfs slowdown with lots of small files" is no longer true.  To be
accurate, the complaint was never with "lots small files" but with
metadata write performance, i.e. deleting, renaming, changing
attributes, etc, of lots of any sized files--operations that saturate
the log journal.

This poor reputation was gained long ago because XFS yielded relatively
poor performance with operations such as "rm -rf" on a kernel source
tree.  Such an operation is metadata write intensive and previously
would bring the XFS log journal to its knees, saturating the physical IO
channel(s) to the disk subsystem, creating a severe bottleneck.  Today
this type of operation is as fast as EXT4 thanks to Dave Chinner's
ingenious delayed logging patch.  It in essence pushes much of the
previous journal IO operations into memory, consolidates the log writes,
and thus decreases actual disk IO eliminating the bottleneck:

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/filesystems/xfs-delayed-logging-design.txt

-- 
Stan