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I've been running a PowerEdge 1950 Generation III with the Dell SAS 6/iR and a RAID 1 array of two SATA SSDs. Since that RAID controller has no battery I wanted to upgrade to the Dell PERC 5/i which does have a battery. I intend to continue to run a RAID 1 array on the PERC 5/i.

I have a backup of the data (but not of the whole disk: Linux + data).

Is it possible to change the RAID controller and have it working immediately afterwards or will the change in the RAID controller result in...

possibility number 1... a dead array but no loss of data meaning I can just switch back to the original controller and no harm was done, or

possibility number 2... loss of data, or

possibility number 3....other problems?

H2ONaCl
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1 Answers1

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RAID controllers store the RAID configuration on the controller itself and the disks also. When disks with an existing RAID configuration are connected to a different RAID controller, the controller uses the configuration on the disks to "rebuild" its own. So, for you, it should be as simple as swapping the controllers and letting the new controller pick up the configuration from the disks.

Regardless, for any operation like this, I would strongly recommend getting at least an image backup / shadow copy before proceeding.

simonlehmann
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  • It all depends on the metadata used by the first controller being compatible/readable by the new one. When dealing with proprietary RAID this is not always true. – shodanshok Feb 12 '17 at 21:01
  • This SHOULD work from PERC6 to PERC5, but firmware versions can play a role there. The specific action to perform after swapping controllers is an "import" of the configuration, which the replacement controller should prompt for. If that doesn't work, you can also attempt recreating the same configuration fresh *without* initializing the disks. – JimNim Feb 13 '17 at 15:07
  • This swap worked. I want to note that the PERC 5 utility did not offer the option to import a foreign virtual disk array. "Foreign" was greyed out. The only available option was to create a new virtual disk array. The creation operation took several minutes so I was expecting the result to be a blank array. It turned out differently. This "setup" was recognized by BIOS and it loaded the operating system that was already on the physical disks. – H2ONaCl Feb 25 '17 at 05:37