xfs
[Top] [All Lists]

re: Software RAID, a bit OT

To: Ben Gollmer <ben@xxxxxxxxxxxx>, XFS <linux-xfs@xxxxxxxxxxx>
Subject: re: Software RAID, a bit OT
From: Greg Freemyer <freemyer@xxxxxxxxxxxxxxxxx>
Date: Wed, 17 Jul 2002 16:55:51 -0400
Organization: The NorcrossGroup
Sender: owner-linux-xfs@xxxxxxxxxxx
Ben,

If you can scrap together another $500, I would consider dropping those Promise 
controllers and adding a 3ware controller.

As I understand it, with the Promise controller you can still only do one disk 
seek operation at a time.  This eliminates the performance advantages of RAID.

Someone please correct me if I'm wrong.

With the 3ware it does the RAID in hardware and does overlapping seeks.  (They 
have just changed there model numbering scheme, so I can't remember what the 
new model numbers are.)

If you stick with Promise controllers, I don't know if RAID 1+ 0 will be any 
faster than RAID 5 or not.  I would guess they will be almost the same speed.  
All the RAID performance descriptions I know assume your hardware supports 
overlapping seeks.

Greg

 >>  Hi storage gurus!

 >>  Hope you don't mind me asking this on-list, but I've gotten some very
 >>  helpful storage-related info from here in the past. I'm putting together a
 >>  server for a small group of developers; we have no real budget, so we're
 >>  trying to keep things cheap. Here's our hardware specs so far:

 >>  2x P3 700 MHz
 >>  512 MB RAM
 >>  2 Promise PCI ATA-133 controllers
 >>  3 Seagate 80 GB HDDs

 >>  This server is going to handle file sharing, e-mail, CVS, and a
 >>  bug-tracking
 >>  database for us. Our project has some rather large files so we need a good
 >>  amount of storage space. I was planning to software RAID 5 the HDDs
 >>  together
 >>  for a total of 160 GBs. I have been enjoying XFS on my workstation but I
 >>  know it has had problems with software RAID 5 in the past. Are these
 >>  problems fixed now?

 >>  We also considered trying to grab another 80 GB drive from somewhere and
 >>  do
 >>  a RAID 0+1 (still giving us 160 GBs storage) but I don't know if Linux
 >>  software RAID handles this well.

 >>  Most of us run the -aa kernel tree on our workstations but I have no
 >>  problem
 >>  running SGI CVS kernels on the server if they are reasonably stable. Any
 >>  input would be much appreciated :)

 >>  Ben






Greg Freemyer
Internet Engineer
Deployment and Integration Specialist
Compaq ASE - Tru64 v4, v5
Compaq Master ASE - SAN Architect
The Norcross Group
www.NorcrossGroup.com


<Prev in Thread] Current Thread [Next in Thread>