Re: Strange delete performance using XFS

Peter Grandi
2007-04-07T13:28:12Z

[ ... slowness deleting a lot of inodes ... ]

>> The Dell system has got a battery-backed write-cache. The
>> 3ware system has no battery unit. However it's supposed to
>> provide write cache, too.

Whatever, but you cannot have both metadata consistency and high
speed without fully reliable hw...

> [ ... ] The Dell's raid system can safely buffer outstanding
> writes and flsuh them, the 3ware can't so it stalls waiting
> fot the disks to catch up. [ ... ] I'd be tempted to just use
> the 3ware as a JBOD and use sw, but I'm arguably biased, I've
> had so many reliability and performance problems with hw raid
> over the years

Uhm, I had a friend that worked for a middling storage system
vendor and he was telling me horror stories about bugs and
misdesigns in their quite popular RAID products.

3ware seem to me one of the more reliable RAID brands, their
cautious approach may be why they are slower above.

> I will almost always use sw raid given the choice.

Does not buy you a lot over well designed RAID host adapter.
it is also a lot less convenient.