large RAID volume partition strategy

[Vivek Khera]

On Aug 17, 2007, at 10:44 PM, Ivan Voras wrote:

>
> fdisk and bsdlabels both have a limit: because of the way they  
> store the
> data about the disk space they span, they can't store values that
> reference space > 2 TB. In particular, every partition must start  
> at an
> offset <= 2 TB, and cannot be larger than 2 TB.

Thanks.  This is good advice (along with your other note about doing  
it in the RAID volume manager).  Nearly everyone else decided to jump  
on the raid level instead and spew forth the "RAID10 is better for  
database" party line.  Well to you folks: once you have 1Gb cache and  
a lot of disks, there is not much difference between RAID10 and RAID5  
or RAID6 in my testing.

I ended up making 6 RAID volumes across all the disks to maximize  
spindle counts and strip the data at 16kB.  This seems to work well,  
and I can assign the other partition as I need later on.