[ale] Disk IO Question

[James Taylor]

I would suggest that your datapaths are not going to be the bottleneck with SATA drives.
I had a client running SATA for several years on an iSCSI  appliance, and one day we hit a brick wall with the mail performance.  We spent weeks trying to tune the I/O paths to deal with it, and when we looked at the actual SATA drive transfer capacity, we realized the drives were the problem.
We replaced the drives with 15k RPM SATA drives, and life has been good ever since.
Check your drive specs and see if that's where the limitation really is.
-jt 
 

James Taylor
The East Cobb Group, Inc.
678-697-9420
james.taylor at eastcobbgroup.com
http://www.eastcobbgroup.com




>>> <mmillard1 at comcast.net> 10/29/2009  04:49 PM >>> 


I have a Suse OES server running on an  IBM 346with 2 gig of RAM.   I've installed two Addonics Multilane SATA cards connect with Multilane cables to external SATA enclosures housing 4 WD Caviar Green 1.5 TB Drives.  



I have about 1.8 TB of Data on one Enclosure which changes daily.  My plan was to copy the 1.8 TB to the second enclosure daily and send the drives in that unit off site.  



My expectation was that by having 4 independant SATA paths per unit  would give me  substatial performance when moving data between these units.  



I'm seeing a constant speed of about 60 gig per hour.  This is much slower than I expected.  Have any of you done anything like this? Is this the kind of performance I should expect?  Hopefull some of you bright people can share some wisdom with me.