Setup of RAID 0+1 using Smart Start 1

[barcoalex]

I'm installing a new ML350 and the specs call for duplexed mirroring (2 SCSI adapters, 1 HDD on each, data written to both as mirror). I have been provided with a 431 adapter for 1 channel, and I am using the integrated SCSI bus (channel 1) for the other.
The problem is Smart Start does not seem to give the option for duplexing (v.5.3). The system is also insistent on setting one of the controllers as the boot controller. Right now that is set as the 431.
How can I configure the server to use both adapters in a duplexing mode of mirror? I need to get the server installed... please HELP!

 

[jkallen]

What you want cannot be accomplished at the hardware level. You will need to setup the system using 1 controller. If you choose to use the 431 (you should), you need to choose RAID 0. Then you will have have to use OS mirroring to "duplex" to the other HDD on plain SCSI.

I assume you want to do this for high availability - you may want to re-think your solution. If the 431 fails, you will not be able to boot off the other HDD without being there to 1)change the boot controller order in RBSU and, 2)put in a boot floppy with a different boot.ini. To make matters worse, W2K may not boot if the boot controller is gone even though you have a backup SCSI controller (this is supposed to work, but only does so about 50% of the time so test it).

Disk duplexing is way overrated and has to rely on software mirroring. Anytime MS mirroring gets involved, you need alternate Boot.ini files. In your situation its even worse because you have 2 very different controllers. Also, that RAID 0 disk cannot be plugged onto your plain SCSI chain and be used by the plain scsi controller. RAID disks are a different format of sorts.

I would just go with the 431 and put both disks on it setup as RAID 1 (you can call it RAID 0+1 if it makes your client feel better, because this is the same thing just renamed when marketing heard about it).

Good Luck

 

[barcoalex]

Thanks for the response. In this case I am going to be installing NetWare 5.1 so the Windows 2000/NT issues are a moot point.
The next question is, is the "no hardware solution" a product of Compaq limitations, or only a problem with 2000/NT? If it is just a MS issue, is there a solution for Novell that allows two controllers?

 

[jkallen]

It's not really a Compaq problem per say and MS just simply enables the ability to do it at all. Back when I was a CNE, there was disk mirroring support in Netware - if its still there, everything above applies the same.

It's just that the Smart-Array controllers were never designed for duplexing without help from the OS, but Compaq's not alone here. I don't know of any other vendor that has cards that do this. I imagine some SCSI controllers are built with this capability, but it would be a very comlicated thing to build with hardware alone. The controllers would have to be aware of each other and stay in sync accross the PCI bus with one acting as a slave of sorts receiving the mirrored data.

Novell has a nice picture of it on their site (

http://www.novell.com/documentation/lg/nw42/index.html?cncptenu/data/hv2sep3k.html)

which shows what you want to do. It appears with this solution, you would not experience any downtime and the OS would handle it transparently. This came for 4.2, however, so I hope it still applies.