Re: Are linux-fs's drive-fault-tolerant by concept?

[John Bradford]

> > Buy IDE disks in pairs use md1, and remember to continually send the
> > hosed ones back to the vendor/shop (and if they keep appearing DOA to
> > your local trading standards/fair trading type bodies).
> 
> 
>   I buy three drives at a time so I have a matching spare, because AFAIC
> you shouldn't be doing RAID on unmatched drives.

Err, yes you should :-).

Unless they are spindle syncronised, the advantage of identical
physical layout diminishes, and the disadvantage of quite possibly
getting components from the same, (faulty), batch increases :-).

>   Using RAID1 is especially important when using software instead
> of hardware for fault-tolerance because the software is more likely to
> have bugs just because of the 'culture' of hardware vs. software
> developers, and the RAID5 algorithm is very hard to get right anyway,
> especially in failure/rebuild mode.  Even on a hardware controller
> RAID5 is still inherently less reliable.

The advantage of RAID1 over a SLED is probably greater than the
advantage of RAID5 over RAID1.

>  (...and what's all this about unreliable drives, anyway?  Every drive
> I have bought since 1987 still works.)

I haven't had a drive failiure for a long time.  Maybe I'm just really
lucky.

John.