Re: [linux-lvm] Allocation Policy for Cloud Computing needed

[Sebastian Riemer <sebastian.riemer@profitbricks.com>]

On 20/02/12 23:41, Ray Morris wrote:
> Since you're using RAID anyway, consider testing RAID 10, which will 
> distribute IO across spindles.

I've already tested RAID-10 with MD as well as letting LVM do the
striping. This is total equal: There are too many IO processes on all
spindles for good performance. All r/w-heads in RAID-10 have to be
repositioned over and over again.
Even in random IO this only reads from a single spindle per RAID-1 array.
Without striping MD RAID-1 has a good read balancing algorithm. With
that I can read from both spindles in the RAID-1 array simultaneously.

> For scripting, see Linux::LVM on CPAN. It gives you that information 
> as a nice data structure. I welcome feature requests and patches. 
> (Linux::LVM::Do coming soon for modifying rather than just querying 
> LVM objects.)

Thanks, I'll look at that.

Cheers,
Sebastian