RAID-5 performance is slow on Poweredge 2800 with PERC 4e/Di
Posted on 2009-04-02
I'm having a performance issue with reading and writing on a Poweredge 2800.
I have a 7 disk RAID-5 array controlled by a PERC 4e/Di. When I copy a 1 GB file from the server to my workstation, it copies at an average of about 4.68 megabytes per second. I've tried other copy configurations (workstation to workstation, other switches, switch ports, etc) but I think I can rule out all of those because when I copy my 1 GB file from a USB flash drive, it copies at 9.09 MB/s.
Why this disparity between reading from the RAID and a USB drive?
This is a server for a small office, and although it is running SQL, Exchange and serving files, there are only about 25 people in the office. When I'm not transferring files, CPU and network usage reported in Task Manager are nominal (average less than 10% and 2.5%, respectively). The system has 4 GB of memory. Windows sees two disks, C: and D:. Both are on the same Virtual Disk on the RAID controller (Bad setup, I know).
The Dell Openmanage application says the PERC 4e/DI firmware version is 521X, and it has 256MB memory. Cache options are Adaptive Read-ahead, Write-back, and Cache I/O.
How can I increase the speed of reading and writing to the RAID array?