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devices is apparently possible at least with some hardware/drivers but when I asked (a year or two ago - so it may be out of date) I was strongly advised to avoid it for a while 'cos that code is new and less well tested.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

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