Poor Disk Write Performance

[Ayman Altounji]

I've got a new G2 DL380 with a Smart Array 5302/64 controller and (6) 72.8GB Wide Ultra3 drives in a RAID5+1 array. We're using this server to store Ghost (.gho) image files and while we get pretty good performance downloading an image (150Mb/min), generating an image or uploading from a client laptop/desktop back to the server is awful (10Mb/min). I'm not seeing any unusual network issues and have the NIC and network ports manually set to 100Mbps/Full Duplex. At Compaq's direction I've updated to latest firmware/software updates for server and controller with negative results. I've even removed the integrated 5i controller at their request with no difference in performance. The kicker is that this server is replacing an old ProLiant 5000 dual PPro 200Mhz, 512MB with Smart-2DH and Wide-Ultra SCSI-3 drives that sits on the same segment and we get 200Mb/min download & 60Mb/min upload on this old platform.

[Ayman Altounji]

Have you adjusted the read/write cache utilization in the Array Configuration Utility? It is possible this is the cause. Have you looked at the desktops to make sure their network settings are 100/Full as well? The 5300 controller is a pretty smoking controller so I DOUBT this is the bottleneck - but possible. I suppose if downloads are all fast then it really wouldn't be network related. If you are running the 5300 controller are you using the pretty (multi-colored) Amphenol SCSI cable? You will need this to achieve Ultra 3 disk speeds.

[Ayman Altounji]

Its the NIC, we have the same issue it depends on the NIC you use and what you have for infrastructure, we set aside a spare CIsco 3524 and hard set the ports to 100 full and we saw performance go up immediately. The internal NIC and the Intel based NICs are dogs with ghost uploads I see anywhere from 10 to 30 MB with those when I switch to a 3com it pops up to close to 80MB. Its definitely not your controller or your disk subsystem

[Ayman Altounji]

One of my colleagues found the solution to this problem. It appears to be a problem particular to an MSDOS client copying data to a Windows 2000 server as described in the following article:

http://support.microsoft.com/default.aspx?scid=kb;EN-US;q244826

The registry tweak didn't work for us, so we used the switch described in the following article as our problem was particular to the MSDOS Ghost client:

http://service2.symantec.com/SUPPORT/ghost.nsf/034d12503a06d36c8525692d0046dbfa/bceb76a54c160ab48825697d006e0405