solstice disksuite - raid 5

[kwilliams99]

Using solaris 8 on an enterprise 450 4 cpu system, with
solstice disksuite.
We have set up a raid5 comprising 8 x 35Gb (8 disks spread over 4 controllers).
We have found that when have copied 35Gb from 1 disk to another without raid or mirroring using cpio , it took
45 minutes, but when copying the same 35Gb from a non-raid disk to the newly created raid5 ufs , it takes over 4 hours.
I was expecting it to be slower but this seems excessive
Is there any tuning or anything that can be done to improve this?
(We don't have any spare disks to do other mirroring, we really need these 8 disks to give a 240Gb filesystem.
Thanks for any advice.

 

[Guest_imported]

Possible turn set ufs:ufs_WRITES=0.

 

[performance]

If you have to move great quantity of data you can maybe think of modifying the interlace size while creating the RAID device.
RAID 5 performance in write are not so good, due to the fact that the system must also calculate the parity.

Hope it helps,
Jeremy