Hello, I have a Dual-controller P2000 directly attached via SAS 6Gb to four ESXi hosts
The P2000 currently has 12x 600GB SAS 15K LFF disks in RAID10, 1 vdisk
We are looking to add around 12TB of usable capacity to it, on RAID10
I wanted to ask if it's better to get:
1x D2600 LFF shelf with 12x 2TB LFF 7.2k rpm SAS disks (3.5-inch SC Midline, 652757-B21 )
or 2x D2600 shelves with 12x 1TB LFF 7.2 rpm SAS disks each? (3.5-inch SC Midline, 652753-B21)
Usually we carve 600-700GB LUNs and present them to our ESXi 5.1u1 hosts
Is there a chance we might hit I/O bottleneck by adding 2 shelves? if I understand correctly the max throughput with the 6Gb SAS interface is 750MByte/sec ? 80% of the storage will be consumed by the 2 hosts.
Are HP 7.2k rpm drives recommended for this SAN or is the performance severely impacted when compared to the regular 600-900GB 15k rpm?
The other option for us would be the SFF version of the enclosure with 24x 900GB 15k rpm SAS SFF disks, which would be about 3x the price. Are these 900GB 15k disks going to give us 3x the performance? I'd like to keep the cost of this upgrade around $8-10k
You have to be aware that SATA disks are not natively dual-ported, the 3.5" MSA disks have an interposer to make them dual-ported but the 2.5" ones do not so SFF SATA are only useful on a single controller model with no failover.
The SAS 6Gb cables/connectors have 4 lanes and these are grouped into a wide port so it's really 24Gb, not that you can achieve anywhere near that with the type or random I/O you'll be throwing at it.
652757-B21 are SC drives, the disks are the same as other SFF ones but they are in HP's new style gen8 caddies and won't fit in the D2700, 619291-B21 is the 900GB SFF disk in the correct caddy. There's also a different part number for exactly the same thing marketed by the Storageworks division rather than the server division but the Quickspecs have been updated to say "HP MSA P2000 G3 Arrays support both the HP ProLiant Server SFF Hard Disk Drives and HP MSA SFF Hard Disk Drives" so you can now use whichever is cheapest.