Duplex RAID contoller on ML350 G4?

[scott campbell_6]

Greetings,

I have a G4 ML350 and I've purchased two 642 Raid controllers, the diagram on the inside lid for configuring multiple RAID controllers on the same drive cage does not match what I have. (diagram shows two SCSI ports, I have one and then two more that have a short cable terminating to each other. The documentation I have found so far indicates that I have to have a separate drive cage with identical drives. I want to have the RAID I'm going to configure in the drive cage to have fail over capabilities to the second controller in case the first one fails. Anyone point me in the right direction?

[Oleg Koroz · Accepted solution]

you need additional
Duplex SCSI Backplane Option Kit 339323-B21
or just card
SPN 371722-001

also option
ML3xx Two Bay Hot Plug SCSI Drive Cage 244059-B21

see attachment

[Oleg Koroz]

correction

SPN 371722-001 actual what you have, stay as simplex in one cage and get optional dual cage, as if I'm not wrong, after dividing standard cage to duplex you have 2 and 4 HDD

[scott campbell_6]

Ok, just want to check my facts:
-I purchase the back plan and the additional cage.
-?-The backplane will allow me to put two controllers onto the existing cage?

-?-Or is the reason I need the Cage expansion so that I can add two more drives to the existing 6 in the cage that came with the server, and then breaking the 8 total drives into two separate raid arrays with 4 each. Essentially mirroring each other

Thanks for your help.

[Oleg Koroz]

With regular cage you have option to configure:

6 HDD
4 and 2
or with optional cage
6 and 2
4 , 2 and 2 (you will be needed three internal channels, with two 642 you don't have that option).

you can create array with any HDD as long it's connected to same array controller.
642 one internal one external.


Select more appropriate option configuration that suitable to your company needs.

[scott campbell_6]

Ok, so the trick then is to make sure that the total disk space in the 2 drive configuration matches the disk space in my 6 drive configuration right?

Thanks again for your help.

[Oleg Koroz]

Hi Scott

I just gave you technical info: possibilities and configuration

Way how you will configure or math you can do on your own. there is nothing to be mandatory how to configure
You named what you need - we answer

Beside that I'm not really sure if configuration with two SA642 controllers installed at same time make big sense. I would keep it on the shelf with spare HDD.

SA 642 they don't fail often.

Use additional HDD as online spare if you really worry.

As if 642 fails you still need access and swap boot order for controller, also you never know a failed PCI card might stop you at POST, till it removed completely.

Installing spare one insight of the box takes 2 minutes.

[scott campbell_6]

Thanks very much for your input, it has helped me very much.

Scott