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

I understand this, but I need the space.  I have databases that are over 3TB and my customers don't want to pay.  I 
just need to get the biggest bang for my customers bucks.  I know you get what you pay for.  I just didn't expect the 
3ware cards to perform so bad.  I think I would have been better off with 4 SATA controllers in the system and do 
software raid.  For my customers that will pay the big $$$, I am using SCSI raid controllers from ICP (now Intel I 
believe).

I am switching all of my 3ware controllers over to Adaptec SATA raid controllers.  I am getting better performance 
with them.  
Jim




---------- Original Message -----------
From: Mikael Abrahamsson <redacted>
To: Jim Buttafuoco <redacted>
Cc: linux-raid@vger.kernel.org
Sent: Sat, 31 Jul 2004 10:49:00 +0200 (CEST)
Subject: Re: 1x 3ware controllers vs. 2x 3ware controllers

On Fri, 30 Jul 2004, Jim Buttafuoco wrote:

quoted

I have a dual XEON 3.2 Ghz system 12 G of ram with a 3ware 8506-8 in it
(8 250 G drives).  The hard raid performance was very bad.  with the
load avg going over 40.  I then switched over to JBOD and software raid.  
The IO wait times are really high and the performance sucks.  Very hard
to explain to my boss where the $20k went. The system is a database
server (postgres).  I tried both kernel 2.4 and 2.6 with the same
problem.  I am now in the process of testing the adaptec raid
controller.

You should never ever ever use raid5 with something that is write 
intensive, such as a database server. Raid5 is a cost compromise that is a 
little of everything, if you want protection and speed at the same time, 
you should use raid1 (and possible raid0 the raid1:s).

I learnt this the hard way running a nntp (news) server.

-- 
Mikael Abrahamsson    email: swmike@swm.pp.se

------- End of Original Message -------