Hannu Krosing wrote:
> How do you do RAID 1+0 with just two drives ?
>
Hmm, good point -- I must have been tired last night ;-). With two
drives you can do mirroring or striping, but not both.
Usually I've seen a pair of mirrored drives for the OS, and a RAID 1+0
array for data. But that requires 6 drives, not 5. On non-database
servers usually the data array is RAID 5, and you could get away with 5
drives (as someone else pointed out).
As I said, I've never personally found it necessary to move WAL off to a
different physical drive. What do you think is the best configuration
given the constraint of 5 drives? 1 drive for OS, and 4 for RAID 1+0 for
data-plus-WAL? I guess the ideal would be to find enough money for that
6th drive, use the mirrored pair for both OS and WAL.
Joe
