- Auto-sector repair. With big disks, this is critical. I've lost software raids in the past due to latent bad block loss that led to more than one disk getting failed out. All big disks have this problem.
- Very reliable driver support. smartd support.
- Hot swap support, good management interface.
Software raid is good for some things, but I would not use it in a machine that requires high uptime. Each of my media servers has 24 400GB drives so ease of managment and reliability is critical. I used to strictly use software raid. No more.
On 3/23/06, Sander <[EMAIL PROTECTED]> wrote:
Tim Berger wrote (ao):
> I have two Linux media servers setup with 3ware 9500S controllers
> using raid "50" with seagate disks. With our configuration this is
> two raid 5's of 6 disks each that are then striped together. I get up
> to about 70MB/sec writes and 300MB/sec reads after the readahead is
> tweaked up.
I'm not impressed at all by 70MB/sec on a raid config. I currently have
eight Maxtor 300GB disks (slow) sw raid5 on a Marvell 8-port sata
controller, and see at least twice as much for writing.
Not to mention that the Marvell 8-port controller is much, much cheaper
than a 3ware 9500S controller.
With 3 controllers and 24 WD Raptors raid5, 500MB/sec should not be a
problem.
Can you try this for me, just for fun? It creates four 10GB files.
for i in `seq 4`
do time dd if=/dev/zero of=bigfile.$i bs=1024k count=10000
time dd if=bigfile.$i of=/dev/null bs=1024k count=10000
done
time rm bigfile.*
With a modern 'dd' it will also output the MB/sec speed.
Kind regards, Sander
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Humilis IT Services and Solutions
http://www.humilis.net
--
-Tim
