Re: Fragmentation of Journaling FS

[Constantin Loizides <Constantin.Loizides@isg.de>]

Hi Utz,

> Sorry, I'm in doubt with the sharp performace drop at 50% disk usage on a
> xfs filesystem.

No need to be sorry :-)

> 
> I made a quick and dirty test running this:
> 
> while time cp -a /usr/src/linux/drivers/ /mnt/xxx-`date '+%s'`; do sync; \
> df | grep mnt; done
> 
Ok, will try this when my test system is available...

Please notice, that I am using a different setup:
different version of xfs,
different file size distribution (i checked that on my /drivers/ dir)

Can you check your test on a small partition of 512 MB, just to 
make sure, that it gives the same flatness?


> 
> My results looks very resonable for me. A sliding performance degrade with a
> full disk. No performace sharp drop at about 50% usage.
Yes, indeed, that looks by far more reasonable, compare it to my 1GB
results which
are also quit smooth and only slowly degrading.


> 
> Is it possible to get your agesystem tool?
> 
Yes, I will make it available on the web.

Constantin