Re: Extreme slowness with xfs [WAS: Re: Slowness with new pc]

From: Justin Piszcz
Date: Mon Nov 24 2008 - 18:53:03 EST




On Tue, 25 Nov 2008, Stian Jordet wrote:

ma., 24.11.2008 kl. 04.50 -0500, skrev Justin Piszcz:
While there still may be something else wrong, the first problem I see is
your sunit and swidth are set to 0.

Please read, a good article on what they are and how to set them:
http://www.socalsysadmin.com/

Oh, this was new to me. But the setting didn't change anything. I can
copy one large file between the xfs and ext3 disk (both ways), and I get
speeds between 160 and 200 MB/s. But unpacking the kernel source takes
between 5 and 10 minutes on the xfs disk, and a mere 15 seconds on the
ext3... (and it also used to take between 5 and 10 minutes when I had
xfs on the raid0, so it doesn't seem to be hardware related...)

If anyone has anything more I can try before I do the lengthy process of
backup 1TB, reformat and restore...

Thanks :)

Regards,
Stian


When you 'unpack the kernel source' ext3 will cache it etc, best way to test:

/usr/bin/time cmd
or
time cmd

where cmd is: bash -c 'tar xvf file.tar; sync'

Make sure its a tar and not gzip/bzip2 (limited by CPU/etc)

The other option is the relatime you stated, use this instead:

defaults,noatime,logbufs=8,logbsize=262144

then tell me what you get
(instead of relatime)

Justin.
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