On Thu, 26 Jul 2007, Michael H. Semcheski wrote:

> So... I haven't gotten to a successful installation yet, but I think I
> figured out what the problem was.
>
> I had a 3ware 9650se driving a 4x750 raid5.  What I forgot to was
> carve (I think this is the term) a boot volume out of the main array.
> That is, now I've got one 50GB drive, and one 2045GB drive, but they
> have the same constituent drives.

Doesn't the 'standard' PC partition-table only allow access up to 2TB for 
devices anyway?  I'd failed to spot that your total size ended up being 
(just) over 2TB which probably causes all sorts of issues...

On the boxes we have with larger raid setups, we are lucky enough that 
they can all chop up the raidset into <2TB chunks which get presented to 
the OS as seperate disks, which we can then join back together with LVM...

Apparently some raid devices can't do the chopping - I've heard this is 
true of some megaraid cards but have never used them myself - at least not 
for so long that 2TB was unthinkable at the time...

> PC's (as far as I know) can't boot off of a block device that holds
> more than XGB, where X is > 50 but less than 2045.  Many RAID cards
> allow you to create a smaller boot parition (which looks like a
> seperate scsi disk to the OS) but is part of the main array.

Support for >2TB devices is apparently possible at least with some 
hardware/drivers but when I asked (a year or two ago - so it may be out of 
date) I was strongly advised to avoid it for a while 'cos that code is new 
and less well tested.  Anyway you need to use one of the new fancy 
partition-table formats...

> Like I said, I haven't finished, because I'm in the process of
> rebuilding the array.  But I'll bet thats what the problem was.

In another 12-24 months I guess single disks >2TB will be out and all 
these things will need to work directly!

  -- Jon