Re: mkfs.xfs questions

[Iustin Pop <iusty@k1024.org>]

On Fri, Dec 01, 2006 at 04:23:41AM +0000, Christian Kujau wrote:
> On Wed, 29 Nov 2006, Jasmin Buchert wrote:
> >Is there any real advantage of making the log size 32-64 MB and
> 
> From 'man mkfs.xfs':
> 
>    If the  log  is  contained within the data section and size isn't
>    specified, mkfs.xfs will try to select a suitable log
>    size depending on the size of the filesystem.  The actual
>    logsize depends on the filesystem block size and the directory
>    block size.
> 
>    Otherwise, the size suboption is only needed if the log
>    section of the filesystem should occupy less space than the size
>    of the special file.
> 
> So, if you're not limited by very special space restrictions, you won't 
> need the "size" option.

I don't understand how you took that conclusion. The explanations refer
to the default log size. I believe the original poster asked about the
performance advantage of *raising* the log size above the default values
for internal logs, and my impression is that metadata-intensive
workloads benefit from increasing the log size (however no hard numbers
are available).

A while back when mkfs.xfs had more conservative default value, bigger log
sizes indeed helped for big filesystems.

Regards,
Iustin