12H Autoraid hooking to 2 x K580's w/MC/Servieguard

[J Lavi]

One of our customers wants to connect 2 x FW-SCSI controllers from 2 x K580's to a single 12H Autoraid for MC/Serviceguard implenation? Will this work? If so how do you configure the cables? D o you recommend a better way?

[David Bell_1]

Joe,

This will indeed work. The idea is to hook both K-580's utilizing (2)A2969A HP-HSC FWD HBA's (for each host for HA)to the Model 12H AutoRAID. To do this, the SCSI address (set on the HBA) should be set to 7 (default) on one host and to 6 on the other host. This is for both HBA's. This will avoid SCSI conflicts. You will then utilize a 'Y' cable with inline termination to connect to the array.

The product number is C2980A for the M/F HVD SCSI ILT (In line termination)cable. Please see the pdf at:

http://www.hp.com/racksolutions/prodinfo/datacables/ds_scsi-legacy-cables.pdf

You can also see:

http://www.hp.com/racksolutions/prodinfo/datacables/ds_scsi-inline-cables.pdf

You will find the manuals for the Model 12H disk array at:

http://www.hp.com/cposupport/manindex/hpsurestor19162_eng_man.html

You should be able to find a connection diagram in the user's manual. Further, you can look at the MC/SG manuals at http://docs.hp.com

The verbage associated to MC/SG from the Configuration guide is as follows:

In-line terminated cables are used in MC/ServiceGuard and High Availability MC-certified systems. They eenable the host bus adapter to be serviced without interrupting the accessibility of the SCSI bus by other hosts. If the host bus adapter card has auto termination, it needs to be defeated by adjusting jumper shunts per the host bus adapter User Guide instructions. In-line terminated cables allow servers and host bus adapter cards to be serviced without inhibiting the remainder of the SCSI bus by removing termination dependency from the host bus adapter.

Be sure you have the latest firmware for the HBA's, Model 12H, and PDC. Also be sure you have the latest patches for WSIO SCSI as well as MC/SG.

HTH,

Dave

[A. Clay Stephenson]

The plan outlined above will work but if you use inline-terminator cables (any you should) make certain that you disable the on-board termination for each controller. The suggested method is standard MC/SG configuration for 12H's.

If you want optimum performance from the 12H, do not vgimport using the -s option but do it manually listing the pv_links manually. If you use the -s vgimport, all the I/O will go through the primary controller (usually X).
What you want to do is setup each VG so that it is comprised of 2 LUN's of equal size. There is absolutely no reason to go beyond 2 LUN's per VG. LUNA's primary path should be through controller X (alternate Y); LUNB's primary path should be through controller Y (alternate X). You then stripe each LVOL within this VG across both LUNS usually in 64k stripes. The idea behind this is that you fully utilize both external data paths. THe other key to performance is to configure no more that 50-60% of the array capacity as LUNs. This will leave the AutoRAID in RAID 1/0 at all times for much better throughput.