Is it possible for a power failure to cause some part of a machine to write one or more random bits to a storage device?
Someone proposed the following idea to address such a risk: create multiple partitions on a single disk which together form a single RAID1 array; then assemble multiple such arrays together as another RAID device; use that to store the file system.
My guess is that this is expected to work since random data cannot be written to each RAID member simultaneously. Perhaps there wouldn't be enough residual power for the drive head to seek forward and write the same random data in each member partition. If all goes to plan, the RAID member with the bad data would be kicked out of RAID after the kernel reads from that block.
Such a setup would likely cause significant performance degredation due to excessive head seeking during all disk IO.
Is the threat of writing random data during power loss a real one? Are there other solutions to this problem?
EDIT: I should have been more clear. I believe the idea of putting a RAID1 on a single disk is a very bad idea. I'm asking about this because I heard of someone who thought it was a good idea and has implemented more than one system like this. I was hoping to put this idea to rest once and for all.
I was trying to figure out what possible reason they would have for this design, but I was later told that this was likely the result of a naive response to unplanned growth during a very hectic time.
I tried thinking of a situation where this might be useful, such as the idea of a payload for a linux filesystem modification getting corrupted, with the command to send the data remaining uncorrupted. I recognize that's unlikely, so it seems that this issue can be put to rest after all. Thank you @gene! : )