On Wed, Mar 14, 2012 at 2:35 PM, John R Pierce pierce@hogranch.com wrote:
On 03/14/12 12:16 PM, Les Mikesell wrote:
If you were running software RAID1 on that box, don't trust anything on the drives now. Maybe even if you weren't, but it is especially weird when alternate reads randomly revive bad data that you thought had been fixed already.
and the worst part is, even if you found mismatching blocks on the mirrors, there's no way to know which one is the 'good' one, as there's no block checksumming or anything like that with conventional RAID.
this is a major reason I *insist* on ECC for any sort of server other than a lightweight home system. ECC memory will detect bit failures so you KNOW something is funky.
I _thought_ the server where I had this problem was supposed to have had 1-bit error correction and I also thought that if the error couldn't be corrected with ECC it was supposed to crash instead of continuing. But maybe it had the wrong kind of RAM installed or something that disabled the ECC.