Moving RAID arrays between servers

Question

We're planning some DR scenarios and one of the things I need to understand is the limits / options for recovering data from RAID 1 arrays where the original server has died. The original server is set up with 2 RAID 1 arrays O/S and data. What I want to do is take the Data array (either as a set or one of the 2 mirrored disks) and see / access the data on the disk from another server.
I need to understand if this is possible on the following servers

Dell 2500 (Perc3/Di) to Dell 2500
Dell 2500 to Dell 2600
Dell 2500 to Dell 2850
Dell 2600 (Perc4/Di) to Dell 2600
Dell 2600 to Dell 2850
Dell 2850 (Perc4/Di) to Dell 2850

From reading around the forums it appears that this is only possible on the Dell 2500 boxes if the new server (recipient) has the same model and firmware of array controller as the old server (donor) due to LUN roaming not being insttalled on the 3/Di card, however I'm really hoping that someone out there can tell me otherwise.

Any ideas?
N

Dev Mgr · Answer

The most important part of being able to boot an OS is the ability to see the data; have the proper raidcontroller driver installed.

The PE2500 ROMB option (PERC3/Di) is an Adaptec solution.
The PE2600 ROMB option (PERC4/Di) is an LSI solution.
The PE2850 ROMB option (PERC4e/Di) is an LSI solution.

If your servers use PCI-X/PCIe raid controllers, then this list wouldn't be relevant, as this list is only the Raid-On-MotherBoard options for each of these servers.

The following section mainly is assuming you're using the ROMB options for each of these servers.

Going from an Adaptec controller to an LSI controller or vice versa I highly suspect won't work properly. Both these vendors store the disk config (or a copy of it) on the drives, but they may have this in a different format from eachother causing drives set up one brand controller to not be properly readable (raid config-wise) by the other brand's controller.

If you check the downloads for the PERC4/Di and PERC4e/Di the latest drivers match in version number (6.46.2.32 as of 4/11/2006), so I suspect that you may have more luck trying to move drives between servers here.

There are a few other factors to keep in mind however. You didn't mention your OSes, but if they're Windows (2000/2003), chipset drivers could play a role, and also the different server models could be using different NIC cards and video solutions, which would make a difference for all OSes (except for video drivers if you're using an OS without a graphical UI, or that uses a generic videodriver).

NacMacFeegle · Answer

Thanks very much for this - unfortunately it confirms what we feared. We are using ROMB for all servers, we're not looking at recovering the OS as I knew this would be different with respect to drivers etc. I was hoping that RAID 1 on an adaptec controller would be readable as RAID 1 by an LSI controller where there was an NTFS volume with data files. I'll need to work out a separate recovery plan for the 2500 units.
Cheers
N

hemerich · Answer

Recovering the OS might also be possible: if you create a boot floppy. Even in a new machine, the boot sector should remain intact. If it is not the first (or Nth controller, as it was in the original machine) you should be able to edit the boot.ini on the floppy and make it work, especially if you try it ahead of time.

PowerEdge HDD/SCSI/RAID

Moving RAID arrays between servers

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