Re: [linux-lvm] LVM2 striping or md raid0

[Chris Cox <chris_cox stercomm com>]

Kelly Byrd wrote:
> 
> 
> On Sat, 22 Sep 2007 18:36:41 -0700, Kelly Byrd <kbyrd-lvm memcpy com>
> wrote:
>> Two questions really:
>>
>> I'm going to use lvm to partition up 4 equal size partitions.
>> I can either use the md driver to RAID0 them the make /dev/md0
>> my PV, or just use the 4 partitions as PVs and stripe across
>> them.
>>
>> How does lvm2 striping compare with md's RAID0 as far as speed?
>> I don't quite get how it stripes on chunk sizes smaller than
>> a PE, but a 4MB stripe size seems crazy.
>>
>> Finally, what's the tuning advice for LVM2 striping? I usually
>> create my RAID0 or RAID5 with 128k chunk sizes, is it similar
>> for LVM2 striping?
>>
>>
> 
> anyone?

This is merely my own opinion, but md was designed to be
THE software raid mechanism.  So, my preference would be
to establish a RAID md device and make that into a PV.

Of course, I don't believe in non-RAID (i.e. RAID0) anyhow.
Maybe someone else will chime in on this one.


-- 
Chris Cox
Sr. Unix Sys Admin