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Chapter 3 System Preparation156 September 2002 HPSS Installation GuideRelease 4.5, Revision 2u There are two loops (a and b) per adapter and two ports per loop (a1, a2, b1, b2)u The physical order of the disks are shown from the perspective of each portu A disk is accessed according to its closest port (e.g., either a1 or a2, b1 or b2)u When planning to configure striped SSA disks in HPSS, it is important to select disksfor each striped virtual volume that span ports, loops, and/or adapters. Thesedecisions can be made after determining the probable bottlenecks and then selectingindividual disks in a virtual volume to alleviate bottlenecks in the port, loop, oradapter, as desired.For SSA disks on an AIX SP node, use maymap to identify which loop the SSA disk is on.• Create volume groups for all disks to be used by HPSS.• Create all necessary raw disk logical volumes to be used by the HPSS Disk Mover(s).To create a volume group for a physical disk, use SMIT or the following:% mkvg -f -y -s To create a logical volume, use SMIT or the following:% mklv -y -traw Note that there are additional options for specifying exactly where on the physical disk thelogical volume should be placed, if that is considered important.To view all physical disks and associated volume groups:% lspvTo view all logical volumes on a given volume group:% lsvg -l • On each Disk Mover node, measure the raw read and write I/O performance of all HPSSdisks and verify that they are at expected levels. Create one or more tables documentingthe results. An example table can be found above. The output of these test should be storedin /var/hpss/stats for later analysis.Use the iocheck.ksh script from the deployment tools package to show the performance ofone or more individual disk devices as well as show the peak aggregate performance ofconcurrent I/O across multiple disks (e.g., to show the peak performance of adapters).To measure the individual and aggregate throughput of hdisks 4, 5, 6, and 7:% iocheck.ksh 4 5 6 7To measure read performance on a single disk:% iocheck -r -t 20 -b 1mb /dev/r |
