CERC Performance Question

[Sturgis, Grant]

Greetings List,

I am experiencing very poor performance with a CERC SATA 1.5/6ch RAID 
card wtih firmware v4.1-0.  Four disks are configured in RAID 5 and the 
OS is RHEL ES 4.0.  I understand that this is not a high performance 
RAID card or RAID configuration (write penalty associated with RAID 5), 
but this just seems ridiculous.

Created a 5GB file with the command:

dd if=/dev/zero of=big_file bs=1024 count=5120000

and then timed a move operation from an NFS mount to the local RAID 
array connected at 1000Mbps end-to-end:

time mv /hosts/server/test/big_file local_test_folder

and the results were:

0.623u 34.342s 9:44.65 5.9%     0+0k 0+0io 3pf+0w

This is over 10 minutes to move that much data over a gigabit 
connection.  What's even worse is that the load average on the system 
exceeded 18 resulting in an unusable system for all other users.  There 
was no response to any commands or login attempts.

Does this seem reasonable to you?  What can I do to improve this 
performance (short of doing away with RAID 5)?

Any comments and suggestions are very much appreciated.

Thanks,

Grant
----------------




Pardon this rubbish:

This electronic message transmission is a PRIVATE communication which contains
information which may be confidential or privileged. The information is intended 
to be for the use of the individual or entity named above. If you are not the 
intended recipient, please be aware that any disclosure, copying, distribution 
or use of the contents of this information is prohibited. Please notify the
sender  of the delivery error by replying to this message, or notify us by
telephone (877-633-2436, ext. 0), and then delete it from your system.