Smart Array 6i - duplex setup

[Casey Black_1]

I had posted this in thhe Proliant forum and have received some useful answers although the do seem to conflict with material I've read elsewhere. Here's the original post:

What is the recommended configuration when using the duplex option on the DL380 G4. We have 6 drives and had planned to have 2 drives in a RAID 1 and the other 4 in a RAID 5.

Would we want to have the RAID 1 on one channel and the RAID 5 on a separate? Or would it be better to mix the RAID 5 between the two channels.

Thanks!

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Subsequent to posting that I had done some reading that seemed to indicate you want to balance the physical drives across the available SCSI channels. My current thinking is to split the RAID 5 between the two channels and have the RAID 1 on one of those channels (the duplex option has drives in the 2/4 setup).

Thanks for any assistance.

[Jacob Zeeman · Accepted solution]

Hi Casey,

When you have the DL380G4 server configured as Duplex the first two slots (Slot zero and one) are on one channel, while the other four on the second channel. If you plan on having the two drives on channel one in a RAID 1 configuration then you have no drives/slots left on the first channel to span the channels for your RAID 5.

If you want to span the channels you'll have to take two drives from the first channel and create an array with two drives on the second channel. Then create your RAID 1 with the last two drives on the second channel. So you can do this, but I think this voids any benefit of using the duplex configuration.

Usually you'll want to create a mirrored set on the first channel, and put your OS on that RAID set. Then use the remaining four drives in a RAID 5 configuration as storage space, on the second channel.

Hope this helps.

Thanks,
Jacob Zeeman
HP Server Storage

[Casey Black_1]

Thanks Jacob. I spoke with HP support yesterday and they too indicated that this was the mose common setup (mirror on one channel and RAID5 on the second). They did however say that splitting the RAID 5 was a valid configuration and that it should theoretically provide a performance improvement (as drive usage on the mirror piggybacked on the second channel would be minimal).

I ended up erring on the side of caution and using the common configuration.

Thanks again.