Question : Raid 6 Performance Problems / best Stripe Size / converting to Raid 5

On a server DL380 G4 HP Server , operates as DC, DNS, Wins, RRAS, and File and Print SErver (System Partition is Raid 5 3 Disks, no write cache)
The Files are all on a direct attachet SCSI MSA20 6x250GB SATA 7.2 + 1 Spare Disk configured as Raid 6. Write/Read cache is enabled)

first time I supported this company they had massive interruption on the file system. So I found out that the write cache was not enabled on that Raid 6 configuration (MSA20 Controller). This improved the performance and the network latency is much better.
But still not like other systems I know. To copy date 10 Gb takes up to 15 - 20 minutes

The network is  GB, Stripe Size of the Raid 6 is 128kb
Windows 2003, NTFS 4kb, Volume type logical

What would you recommend to improve this kind of configuration
Reduce Strip size to 64 kb or direct convert to raid 5 (just not secure as raid 6). Files are mixed small and large word, excel etc , large ppt's , jpg

Answer : Raid 6 Performance Problems / best Stripe Size / converting to Raid 5

A couple of things come to mind.

1. a 3 disk raid 5 with no write cache on your system RAID will be slow. You should convert to a mirror.

The MSA20 needs an External RAID controller if I remember correctly. The external RAID controller probably isn't that good if it came with the DL380 G4 and MSA20. It is likely overworked by using a RAID 6 configuration. The best modern controllers struggle with RAID 6. I would consider moving to a RAID 5 with a hot spare or upgrading the RAID controller to a better model with a large cache (256-512) and BBWC.