drive failure during rebuild causes page fault

[Peter Jeremy]

On Wed, 2004-Dec-15 19:16:59 -0500, asym wrote:
[audio jukebox]
>>what would be your recommendations for this particular (and very limited) 
>>application?
>
>Honestly I'd probably go for a RAID1+0 setup.  It wastes half the space in 
>total for mirroring, but it has none of the performance penalties of 
>RAID-5,

If you're just talking about audio, then RAID-5 would seem a better
choice.  You get much higher effective space utilisation (75-90%
rather than 50%) and even the degraded bandwidth is plenty for serving
a couple of audio streams.

> and upto half the drives in the array can fail without anything but 
>speed being degraded.

Normally, you replace a drive soon after it fails.  The risks of a
second drive failing should be fairly low.  Note that you should try
to get drives from different batches - all vendors have the occasional
bad batch and you don't want all your drives to die at once.

>RAID5 sacrifices write speed and redundancy for the sake of space.  Since 
>you're using IDE and the drives are pretty cheap, I don't see the need for 
>such a sacrifice.

For Gianluca's application, write speed wouldn't seem to be an issue.
Redundancy may or may not be an issue - it depends how quickly a
failed drive can be replaced and whether the risk of one of the
other drives failing during this period is acceptable.

The main advantage of RAID-5 is increased space - and this would seem
to be an important issue.

-- 
Peter Jeremy