Re: 1x 3ware controllers vs. 2x 3ware controllers

[Mark Watts <mrwatts@fast24.co.uk>]

> On Sun, 1 Aug 2004, Mark Watts wrote:
> > RAID Configuration:
> > 4-disk RAID-5 with 64K block size.
> >
> > /dev/sda1 = / = 20GB
> > /dev/sda2 = swap = 2048MB
> > /dev/sda5 = /home = 100GB
> >
> > All partitions (except swap) formatted as ext3.
>
> It would be interesting to see difference if you put the system and swap
> on another drive that is not part of the RAID5.

With 2GB ram, I can disable swap entirely if you want, but I don't have 
another drive to put it on.

>
> > Kernel - 2.6.8rc1, SMP for x86_64
>
> I use v2.4, haven't used 2.6 with 3ware and SMP at all, so the problem
> might be there. Did you try the smp_affinity thing I emailed about 1-2
> days ago?

No - The system is at work - I'll try it on Monday.

>
> > Slow write speeds is one thing, practically locking the system up while
> > the write occurs is another, unless I'm missing something obvious.
>
> Well, if the system needs to page-in and this page-in takes seconds to
> fulfil because the raid5 is full at work and has a large latency queue,
> that might explain it. Does the system do anything else when you're
> copying?

No (thats the point!). Playing (or rather skipping) mp3's with xmms is about 
the most it does.

I'm going to try using xfs instead of ext3 on Monday too.