xattr performance and Samba4

James Peach jpeach at sgi.com
Tue Nov 23 22:50:02 GMT 2004

On Tue, Nov 23, 2004 at 04:14:13PM +0100, Bjoern JACKE wrote:
> On 2004-11-23 at 17:41 +1100 tridge at samba.org sent off:
> >The results are quite interesting, and show quite a large difference
> >between the different Linux filesystems. I haven't tested any
> >non-Linux systems that support xattrs yet.
> there has been another ACL Test some time ago been made by Andreas 
> Grünbacher, this one says that JFS is much better than JFS looks in 
> your tests. One of the reasons which might explain it's good ACL/EA 
> performance (which can't be seen in your benchmarks ;) ) might be that 
> Linux JFS is the JFS2, which was developed for OS/2, where ACLs and 
> AEs are excessively used. Also it shows some more details about the 
> technical background of the ACL/EA support of the different 
> filesystems. Interesting for example: XFS doesn't support many ACLs at 

XFS does up to 25 ACE per ACL.

> all, while other filesystems support up to 8k. Another bonus of JFS 
> and it's OS/2 history is that it can be made case insensitive, which 
> might give us a great performance gain if we rely on that.

XFS also has a case insensitivity option. I haven't been able to
demonstrate that it's a big performance win in Samba3, but I'm happy to
be corrected :)

James Peach | jpeach at sgi.com | SGI Australian Software Group
I don't speak for SGI.

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