Replaced RAID5 Disks, Want to Swap old ones back in---HOW?

[YogiBear79]

Synopsis: We took down one of our PowerEdge2650's and replaced the entire disk array, rebuilt the RAID5 and rebuilt the OS.

Long story not worth going into. How can I safely swap in the old set of disks, and get the computer to boot without damaging the data. And then obviously, swap the disks one more time to the current ones?

 

[technome]

Assuming the 2600 has a SCSI raid...

I sure hope you have the original disks marked as to which slot they came from. Likely you have a controller which will allow disk roaming, but drives can not roam to a channel from which they were not on originally. If you do not return the original disks to the corresponding channels you are in trouble.

Pull the "new array", mark the disks as to which slot they came from in case you want to reverse it again.

Go into the controller and clear the configuration, after you have documented the present configuration.

Restart the server, place the "old" array back in, do not configure.
Restart the machine, the boot up should balk, and declare a configuration mis-match, at which time it should ask if you want to use the configuration on disk (COD), obviously you do; the configuration will be read from the disks and saved in the raid bios, server will boot to OS. All should be fine.

To reswap the "new "array back in again, same procedure as above.

If you do not know the order of the drives, and you were using more then 1 channel of the raid card, do not do the above.


........................................
Chernobyl disaster..a must see pictorial

http://www.kiddofspeed.com/default.htm

 

[xxzab]

i believe with dell you need to recreate the drive config in the raid card, that is the case for 1800's dells,

WARNING but do not initialize the disks this will wipe the data off them

If you have a test server try this there first

second thing you can do if you cant get the old disks to work is to restore from backup.

Eric
Whirlpool Corp.

 

[technome]

I believe with dell you need to recreate the drive config in the raid card, that is the case for 1800's dells,"

You do not need to reconfigure !!!... with the configuration cleared, the raid adapter with read the raid configuration which is saved on the array ("Configuration On Disk"). I would not advise trying to configuration the raid in the raid bios, as it is easy to mess things up.

The other way is, from within the raid bios..
Step1. Press <Ctrl> <M> when prompted during bootup to access the
BIOS Configuration Utility.
Step2. Select Configure—>View/Add Configuration.
This gives you the option to view both the configuration on the
NVRAM and the hard drive disk.
Step3. Select the configuration on disk.
Step4. Press <Esc> and select YES to update the NVRAM.
Step5. Press <Esc> to exit, then reboot

http://lists.freebsd.org/pipermail/freebsd-stable/2006-February/022657.html

........................................
Chernobyl disaster..a must see pictorial

http://www.kiddofspeed.com/default.htm