Raid 5 on two scsi buses with different maximum speeds

Question

I'm quite a noob, I'm trying to set up as a study machine an old HP ProLiant DL385 G1.

I've configured a RAID 5 out of six SCSI 3.5" HDDs using: - Smart Array 6i controller; - (4 x SCSI Ultra320 36,4GB disks, 15K) AND (2 x SCSI Ultra3 36,4GB disks, 10K), all on the same local SCSI bus.

Now the disks should run on the SCSI bus at most @ 10K, 160MB/s, as imposed by the slowest Ultra3.

If I put the two groups of disks on two different SCSI local buses, would the overall performances of the array be improved? The two-buses configuration requires an optional terminator board...

I cannot resist asking: so it is not possible to create a single array raid 5 out of six disks on two different scsi buses? — anto, Apr 30 '14 at 15:14
You can, yes... if you use a dual-channel controller like a Smart Array 6402 or 6404. — ewwhite, Apr 30 '14 at 15:27
Thank you, I'll check out again the documentation for the Smart Array 6i! — anto, Apr 30 '14 at 15:44

score 2 · Accepted Answer · answered Apr 30 '14 at 14:32

Don't bother. The split-bus/split-channel (aka "Duplex Mode*") design was only helpful in separating OS and data drive activity and offering an opportunity to use multiple Smart Array RAID controllers. It would break your 6 bays into 2 + 4 bays.

Just use the system as-is, though. The stakes are low, and this is very old equipment/technology.

Raid 5 on two scsi buses with different maximum speeds

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