retriving data off one disk of a mirror

[Andrew McKellar]

I'm working with about 10 DL380 G3 that has had one of their drives removed for data protection. I'm trying to get some information off these drives by mounting the ext2 partitions and copying the data to an array. I can't seem to figure out how to get the drives to be seen by the raid controller without clobering the drives. Currently, i'm using a linux boot from cd dist called Recovery is Possible and it doesn't support the rpms that are provided by compaq/hp. Any thoughts would be very helpfull...
Andrew.

[Greg Carlson]

Andrew,

Back on the netserver side, since Raid 1 is just a mirror copy, it also is usually readable by a JBOD scsi HBA like an adaptec or symbios controller. Try to just access the drive without going through a SAC. The SAC will want to initialize the drive and wipe out the data.

Ciao,
Greg

[Uwe Zessin]

Remember that the SmartArray controllers put their configuration data on the disk, too. I don't know how big that area is and if it is at the beginning or at the ending of the disk.

Removing disks from a SmartArray controller 'for data protection' = split mirror cloning - is not a supported operation.

I won't be surprised if people tune in and tell that it has worked for them. That's OK with me ;-) Just be warned that this is not 100% safe. I know people who have lost their data.

[Andrew McKellar]

When I put the drive in a Dell poweredge PERC controller, i was able to 'see' the drive but there was a single partition of type 12 called 'compaq diagnostics'. The partition was from 1 to 1 cylinders...?!? I'm still looking for ideas on how to get this data off the drives. Thanks for the help so far!

Andrew.

[Uwe Zessin · Accepted solution]

All universal SCSI disk drives come with this #$*% type 12 partition, by the way. It is possible that the SmartArray controller starts using the disk a few blocks later, so you see the factory default from block 0.

I am afraid the only true way is to stick the disk back into a SmartArray controller. You must put it back into its original slot position, else you are attempting a 'drive roaming with a reduced disk array' which is - guess what? - not supported either. It might work - it might not work.

[Leslie Martin]

Andrew
RAID Controllers write a small amount of data called a 'Raid Information Set' to drives attached. This basically tells the Controller which drives, their physical locations in the drive cage and the type of RAID set they belong to ie RAID 5. Controllers from different manufacturers write this informatiuon in diferent ways which is why a RAID Controller from Dell ie PERC may not be able to see the data written by say a Smart Controller. As the drives originally came from a DL380G3 you should be able to see your data if you connect the drives to a modern Smart Controller