What happens if

What happens if you swap two disks in RAID array while the system is powered down?
If there were, say, three disks A, B, C, on three channels 1, 2, and 3 respectively.
Change the configuration so that disk A is now on channel 2 and disk B is now on channel 1, then power on.

Most likely, nothing happens.

The outcome depends on the method the controller uses to identify the disks. Most if not all modern controllers identify their disks by writing some identification data onto the disks. This way, the controller can tell what the order of disks is by looking at the disks themselves. In earlier days, there were some controllers identifying the disks by ports the disks are connected to. These would be fooled by the swap. Modern controllers (in most cases) carry on just fine.

I just tested it with Silicon Image Sil 3114, and Promise SureTrak EX4650, just in case.
Also, all modern software RAIDs (Linux md-raid and Windows LDM/Dynamic) will also handle this just fine.


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