What kind of performance should I be getting from a RAID 5 disk array with 4 hard drives rated at 6GB/sec in each array (total of 4 arrays on a Promise card). It's on a 64 bit Linix system and when I run the dd disk speed test I'm getting abotu 1.3GB /sec/
Try StreamFab Downloader and download from Netflix, Amazon, Youtube! Or Try DVDFab and copy Blu-rays! or rip iTunes movies!
+ Reply to Thread
Results 1 to 4 of 4
Thread
-
-
I'd say that was pretty darn good. That rating of 6GB/sec is probably not the sustained read rate anyway. Once the read cache is used up you're down to strict disk i/o. You should be pretty happy. At 1.3gb/sec your probably maxing out on the bus/backplane speed.
Note: You mean 4 drives in a 5 disk array, not 4 arrays. Though it may be a naming convention with Promise that I'm not familiar with. This gives you the space of three usable drives and with fourth used as the parity drive. Great for read performance with a slight hit on write performance. (Takes a little extra work to create the parity stripe.)Have a good one,
neomaine
NEW! VideoHelp.com F@H team 166011!
http://fah-web.stanford.edu/cgi-bin/main.py?qtype=teampage&teamnum=166011
Folding@Home FAQ and download: http://folding.stanford.edu/ -
OK, correction. 6GB/sec is interface. Actual disk speed rating in 600MB/sec. Light bulb finally went off earlier today and I checked a volume not on the RAID array and got numbers about half what I'm getting from the RAID array, so I guess it really is working right.
-
As luck would have it, I'm right in the middle of repairing 2 Servers that had RAID 5 systems (electrical problems), and after having one server be irreparable (sp?) because more than 1 drive went bad during rebuild, I've come to the conclusion that it's faster and safer to go with RAID 10. Once they're all up and running/serving again, I post a benchmark of their speeds. Read online about how RAID 5 isn't really secure anymore w/ large HDs, and even RAID 6 won't be in 5-10 years.
Just a suggestion.
Scott
(thank God I've got backups!)Last edited by Cornucopia; 18th Feb 2011 at 17:45.
Similar Threads
-
RAID controller question...
By RogerTango in forum ComputerReplies: 12Last Post: 21st Oct 2011, 23:59 -
Software raid over IDE & SATA disk
By RabidDog in forum ComputerReplies: 5Last Post: 11th Jun 2010, 22:58 -
Which is better for speed and performance?
By SIRCOOKS in forum ComputerReplies: 3Last Post: 20th May 2010, 22:03 -
RAID question
By mysts in forum ComputerReplies: 5Last Post: 6th Jul 2009, 15:31 -
RAID-0 Backup Question
By Gromit137 in forum ComputerReplies: 19Last Post: 2nd Jan 2009, 06:47