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

On Fri, 2004-07-30 at 00:15, Mark Watts wrote:

quoted

I'm looking at building what I guess you could call a budget NAS
array.  I'm looking to start with four 250MB SATA drives on 3ware
8506-4LP controller.  I eventually want to move to eight drives in the
box.  Is there any reason to expect that the performance of eight
drives spread across two 8506-4LP controllers is going to be any worse
then the same eight drives all on one 8506-8?

oh one thing I forgot -- are you going to use software RAID or hardware
RAID?  Because with hardware RAID, I don't think you can spread a RAID
across two controllers.  That might affect your decision.

With the performance issues I'm seeing with the 8506-4LP's I have, I wouldn't 
recommend them to anyone currently...

The thread on LKML from a few days ago about mke2fs -j and 8506-4LP says it 
all, but basically and reasonable amount of I/O brings a Dual Opteron system 
to its knees.
And by reasonable I mean copying ISO images from a usb2 drive to a raid 5 (4 x 
250GB maxtor) or even just formatting a 600MB partition.

I've been able to get nearly 1.5 Gbits/sec off of an 8506-8, with 8
250GB disks...  of course those are all 1 megabyte reads (but from
random locations).  Is your problem related to # of IO's, or size of
transfer?

	Scott