[mythtv-users] Hard Drives that Actually Work?
bam at snoopy.apana.org.au
Wed Dec 15 22:04:34 UTC 2004
>>>>> "Asciimonster" == Asciimonster <asciimonster at myrealbox.com> writes:
Asciimonster> Erroneus read data cannot be corrected in any way,
Asciimonster> so that's all in the game. And that only corrupts a
Asciimonster> few files while a complete hard disk crash just
Asciimonster> looses you entire info. And if I understand you
Asciimonster> correctly, RAID1 *does* protect you againt
Asciimonster> that. Moreover the CRC checks on hard disk makes it
Asciimonster> report an error before it get's the chance of
Asciimonster> reading the wrong info.
I have heard of a case when a cheap hard disk in a RAID1 setup failed,
however it didn't report its failure. The hard disk just returned
random data. Yes, CRC should protect against this, but it
didn't. Maybe the hard disk didn't properly check the CRC. Or maybe it
died to such an extent it could no longer control the IDE
interface. What happened is a mystery. The computer read this random
data from the faulty hard disk (not just file data, file system meta
data too) and wrote it to the good hard disk. The result really was
all information completely lost.
1. This didn't happen to me, it is my recollection of events told be a
2. You could argue that it was the fault of the hard disk not
returning a failure error code - I agree.
Brian May <bam at snoopy.apana.org.au>
More information about the mythtv-users