[mythtv-users] Why RAID 5 stops working in 2009

[jedi]

On Fri, Oct 24, 2008 at 03:11:17PM -0700, David Brodbeck wrote:
> On Fri, October 24, 2008 1:57 pm, jedi wrote:
> > On Fri, Oct 24, 2008 at 01:54:11PM -0700, David Brodbeck wrote:
> >> On Fri, October 24, 2008 12:45 pm, Mache Creeger wrote:
> >> > Should we just pray that although the statistics say otherwise,
> >> > native RAID5 on Linux will not self-destruct when using many large
> >> > capacity drives?
> >> >
> >> > Any ideas?
> >>
> >> Don't use RAID 5.  Use RAID 10 instead.  See this page for a humorous
> >> take
> >> on why:
> >> http://www.miracleas.com/BAARF/BAARF2.html
> >
> >     ...I've been thinking not RAID 10 but LVM on top of RAID1.
> 
> Sure, that's basically the same thing.  RAID 10 just means you're taking a
> bunch of RAID 1 mirrored pairs and striping data across them RAID 0 style.
>  RAID 01 is the opposite; it's taking two identically-sized RAID 0 stripes
> and mirroring them.  Functionally the two are equivalent, except I think
> RAID 10 has some advantages when you have to rebuild.

      I would expect that RAID1 + LVM would have the advantage since
the rebuild would only need to occur from one drive to another. My main
reason for choosing that over RAID10 would be the ability to incrementally
add and remove mirrored pairs from the LVM as drives get upgraded. I would
be less interested in speed than the fact that all the disks are presented
as a unified storage space.

[deletia]