[mythtv-users] Hard Drives that Actually Work?

Phill Edwards phill_edwards at hotmail.com
Wed Dec 15 23:04:11 UTC 2004

>     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
>    friend.
>2. You could argue that it was the fault of the hard disk not
>    returning a failure error code - I agree.

I had a RAID mirror set up for a while on my home Internet 
gateway/NAT/firewall box. In the end I turned off RAID in favour of setting 
up a nightly backup onto the 2nd disk with rsync. That way if I accidentally 
deleted/stuffed up something I could get the previous version back from the 
backup disk. With  RAID I couldn't do that. Sure, I could have backed up my 
RAID disks but this ain't exactly a mission critical setup and I'd have to 
buy yet more disk. The way I have it now I can lose 1 day's worth of data, 
but I could modify the backup regime if that worried me.

I think it's good to question whether RAID is the best solution for a home 
setup. Sometimes there's a simpler more useable solution that gives you more 
of what you need for most scenarios.

I'll just go and put my flame suit on now...

More information about the mythtv-users mailing list