Re: nfs/local performance with software raid5 and xfs and SMP

[Steve Lord <lord@xxxxxxx>]

> 
> Just one comment here, the configuration in case c) is never a good idea,
> the raid code will automatically cause the disk head to thrash around
> that is why the performance is so bad there. I am not totally sure why
> we can do a reasonable job on deletes on a single disk, but not on a
> raid - there are synchronous writes in there. Unless your single disk
> xfs is on ide with write caching turned on. One more comment on xfs
> delete speed is that multiple parallel threads doing deletes will
> run faster than a single thread doing deletes, so lots of different
> threads doing deletes will not be as bad as a single large directory
> delete.
> 
> Steve
> 


I made a mistake here I meant config b) not c) - it looks like write
caching is on in this case.

Steve