Win2k3/Exchange Box RAID Configuration Suggestions

[Colebert]

ok, so i'm configuring an Exchange 2003 box (to be used exclusively for this purpose) to be put into production on a domain with two other domain controllers. The system is a Dell PE1800, 1x2.8GHz w/ 1GB RAM.

My question is how to configure the storage subsystem. Here are my pieces:

Intel PCI-X 2ch U320 RAID Adapter
4x Fujitsu 73gb 10K U320 drives (MAP models)
2x Hitachi 73gb 10K U320 drives (storage review rates slightly less than the MAP)
2x 4 device U320 scsi cables


how should I arrange the setup?

OPTION 1: (I was originally leaning towards)

2x Hitachis in RAID1 as system drive
3x Fujitsus in RAID5 for exchange storage
1x Fujitsu for hot spare
(array 1 on ch1 w/ hot spare; array 2 on ch2)

OPTION 2:

All drives in RAID5 array w/ 1 reserved for hot spare


OPTION 3:

All drives in RAID50 array w/ no hot spare




What would the experts recommend (either from given options, or other ideas)

 

[imported_Kensai]

Option 2.

 

[Matthias99]

I'd lean towards option 2, although you might also consider a RAID10 (though I'm not sure if that controller supports 6-drive RAID10 arrays). You might get better write performance than with a RAID5 -- but it would cut down your capacity quite a bit. I don't know how much data you're expecting to have to keep on the server.

 

[Colebert]

thanks for the input so far.

roughly 50 users mailboxes so space isn't tight. currently we are using MSMAIL w/ PSTs stored on a novell file server that has probably 50gb total, so space won't be a critical issue, just moderately important to plan for the future.

RAID50 not worth the cost?

 

[Colebert]

controller is Intel SRCU42X Ultra320 SCSI. seems to have lots of features.

 

[Matthias99]

Originally posted by: Colebert
thanks for the input so far.

roughly 50 users mailboxes so space isn't tight. currently we are using MSMAIL w/ PSTs stored on a novell file server that has probably 50gb total, so space won't be a critical issue, just moderately important to plan for the future.

RAID50 not worth the cost?

RAID50 isn't a standard RAID level... that would be, what, a RAID5 made out of three or more RAID0 arrays? Doesn't seem to make sense; it's not much more fault-resistant than regular RAID5 (you can still lose your data if two drives go down, though sometimes you would be OK), and RAID5 is already striped (so I don't think it would improve performance much, if at all).

 

[Colebert]

i wasn't sold on the idea, but it was in the intel brochure as having better read performance than RAID 5.


would it help my performance any to do the RAID 1 system drive, then a smaller RAID5 array for the exchange storage?

 

[lansalot]

Option 2 definitely.

 

[Matthias99]

Originally posted by: Colebert
i wasn't sold on the idea, but it was in the intel brochure as having better read performance than RAID 5.

I'm not seeing how it would help performance at all. RAID5 already stripes both data and parity across all the drives involved -- "RAID50" would just be a second layer of striping underneath the RAID5. It gives you a slight improvement in redundancy at the cost of some of your space (with six drives, you'd have five drives worth of usable space with RAID5, but only four drives' worth with RAID50). Maybe I'm missing something.

would it help my performance any to do the RAID 1 system drive, then a smaller RAID5 array for the exchange storage?

I don't think it would make a meaningful difference. You probably won't be hitting the system drive/partition much in normal operation.

 

[Colebert]

sounds good.


is there any good reason to split arrays across channels?

 

[lansalot]

Yes. Throughput being the main one.

 

[Colebert]

in my head that was the reason, but i had not gotten official confirmation on that.

thanks.