Re: Advice on raid/lvm
On Thu, 09 Apr 2009, Mark Allums wrote:
>> Is there an advantage of software raid10 over multiple raid1 arrays
>> joined with LVM? Capacity can be dynamically added with pairs of disks.
>
>
> Only one: simplicity. It would make it easier for someone to
> understand, in the beginning.
Well, md-raid10 is actually raid 10, not stripping stacked on top of a
mirror. It has the concept of near and far copies of raid blocks, and one
of the possible configurations reduces to the same layout you get when you
stripe data over two mirror sets. It is supposed to be able to perform a
lot better than device-mapper on top of two md raid1 sets ever could, but I
didn't test that to check.
What I *dislike* in md-raid10 is that it is more difficult to chose the
right disks to remove when you want to remove all possible disks from an
array without losing data, and also that either the kernel or the tools
didn't let me create a raid set with half the devices missing last time I
tried that (but that may have been fixed already on latest mdadm + latest
kernel).
--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
Reply to: