Cloning HDDs from a hardware RAID array?
Is it possible to clone the individual disks of a hardware RAID to get a copy of the contained array?
I have an Adaptec RAID controller. I put it offline, attached the RAID member HDDs to a regular SATA port and tried to clone the disks to some other disks using G4L using the RAW mode. It looked like the clone process did work based on the amount of data copied. But after I used the cloned disks on the Adaptec RAID controller, it did not find any arrays but did detect the disks.
I wonder if it is even possible to clone the disk or if there is some data that has to be copied in another way?
Update: As there where some questions on the how and why:
- the array in question is causing problems and I figured it would be the safest way to clone the disks and work with the copy instead of the original disks.
- the array did not fit on one disk (to clone to) so I figured it would be the way to go
- I don't have enough NAS storage available to clone the array to
- I tried to clone to larger disks as the original model is no longer available (no longer sold) and I'm out of replacements
- I did power down the system before (and between) copying/switching the disks to avoid hotswap detection issues and confusing the controller and having a consistent state between the disks
Solution 1:
Is it possible to clone the individual disks of a hardware RAID to get a copy of the contained array?
yes, it is possible to copy individual disks. Regardless if they are part of a RAID array or not. Just power the computer with the drives in it down, move the un-powered drive to another computer * and copy it.
There are many methods to do the last. Some of them are:
- Full disk image (e.g. with Norton Ghost)
- Full disk image (e.g. with Acronis)
- A simple
dd,catorcpof the whole drive (any unix like OS, either installed or from a LiveCD/LiveUSB.
Any of those will do as long as the disk you are copying is not in use.
You can even read from the disk and store the copy somewhere on the network (e.g. use cat piled though netcat).
I have an Adaptec RAID controller. I put it offline, attached the raid members HDDs to a regular SATA port and tried to clone the disks to some other disks using G4L (http://sourceforge.net/projects/g4l/) using the RAW mode. It looked like the clone process did work (amount
According to your link g41 supports raw copies of whole disks. That should have worked.
of data copied), but after I used the cloned disks on the Adaptec RAID controller, it did not find any arrays (but did detect the disks).
Dis you copy to identical disks? (Read: Did you copy to disks with the precise same size? Copying from 2TB to 2TB (with the second 2TB being a few KB smaller) might cause lots of problems if there is data in the last sector of the disk.
Vice versa: larger disk might also cause problems for the same reason.
So I wonder if it is even possible to clone the disk or if there is some data that has to be copied in another way?
A 1:1 raw copy to a identical disk should work.
it is a weird way to copy data though. Normally you would just create a second RAID array (or wipe and restore the original RAID) and restore the data from backups.
This leads me to the idea that you have "problem X" and that you are trying to solve that by "method Y". That might work but adding why you want to do this strange thing might help a lot.
*: The reason to use another computer is that the RAID card might detect that a drive has been removed and drop it from the array. Thus power it down, remove the drive, copy the drive and place it back before powering on the RAID card.
(Unplugging the RAID card might also work).