Hi all,
We're getting a number of 2 node 8440s delivered with what looks like an odd configuration to me.
total of 4 drive shelves (shelf with nodes + 3 extra drive shelves) and 20 * 3.84TiB SSDs.
Expected configuration is mean to be RAID-5 3+1 HA
Is that a valid config ? I thought drives had to be put in pairs per shelf ? (from the best practises guide) I did ask the HPE person and got told to read up on "Express Layout", but even though that allows the 2 nodes to share PDs when creating LDs it still doesn't feel like it would allow an odd numbner of drives per shelf.
Anyone have comments ? Or a good link to "Express Layout" as I can only find the same paragraph repeated in multiple diocuments.
I may be over thinking things!
Code:
Express Layout
This unique technology born from the HPE 3PAR three-layer virtualization technology allows 3PAR controller nodes to share access to SSDs in
order to further drive efficiency. Replacing traditional layouts for flash, Express Layout allows each SSD to be actively accessed by both
controllers in a node pair at the same time. This allows a node pair to use capacity from every drive to build logical capacity. For smaller
configurations, like an eight drive system, Express Layout allows the nodes to significantly reduce the overhead historically associated with parity
RAID layouts and can result in more than 10% reduction in overhead which increasing performance by allowing more than one controller to drive
I/O through the drive