I'm experiencing some really horrible performance problems on an AIX
5.2 machine with a jfs2 file system.

Try the following:

# make a dummy file
dd if=/dev/zero of=tmp bs=1024k count=1

# time creating 1000 hardlinks
time perl -e 'for ($i = 1; $i < 1000; $i++) { link("tmp", "tmp.$i"); }'

# time removing 1000 hardlinks
time rm tmp.*

Both creating the hardlinks and removing them takes about 7 _seconds_
on my AIX machine (on a local disk). Other compareable OSes (Solaris,
Linux, HP-UX, ...) can easily do this 100 times faster.

So - I'm wondering, what am i missing? Is there some option somewhere
I forgot to enable?

- Finn Arne

On Feb 6, 1:33 pm, Finn Arne Gangstad <fin...@fire.pvv.org> wrote:
> I'm experiencing some really horrible performance problems on an AIX
> 5.2 machine with a jfs2 file system.
>
> Try the following:
>
> # make a dummy file
> dd if=/dev/zero of=tmp bs=1024k count=1
>
> # time creating 1000 hardlinks
> time perl -e 'for ($i = 1; $i < 1000; $i++) { link("tmp", "tmp.$i"); }'
>
> # time removing 1000 hardlinks
> time rm tmp.*
>
> Both creating the hardlinks and removing them takes about 7 _seconds_
> on my AIX machine (on a local disk). Other compareable OSes (Solaris,
> Linux, HP-UX, ...) can easily do this 100 times faster.
>
> So - I'm wondering, what am i missing? Is there some option somewhere
> I forgot to enable?
>
> - Finn Arne


september:/tmp# time perl -e 'for ($i = 1; $i < 1000; $i++)
{ link("tmp", "tmp.$i"); }'

real 0m5.06s
user 0m0.02s
sys 0m0.11s
september:/tmp# time rm tmp.*

real 0m5.12s
user 0m0.05s
sys 0m0.10s

Seems like user+sys is small. Real time is large because of disk I/O
waits.
I think jfs commits the change to disk before returning.
--S