How to achieve over 2 TB/hr network backup with Integrity entry-class servers running HP-UX 11i v3

17
ports or paths should be added to the system for greater throughput and efficiency. This
characterization benefited immensely from the ability to capture client data read and write metrics for
backup and restore operations on the client systems.
The following is an example of sar –H command output. In addition to displaying the number of
I/O operations per second (as does the sar –d command), the sar –H command displays more
details about Reads and Writes.
# sar -H 10 3
HP-UX hpsas002 B.11.31 U ia64 06/29/09
13:36:39 ctlr util t-put IO/s r/s w/s read write avque avwait avserv
%age MB/s num num num MB/s MB/s num msec msec
13:36:49 sasd1 100 35.52 570 0 570 0.00 35.52 1 0 6
13:36:59 sasd1 100 35.32 566 0 566 0.00 35.32 1 0 6
13:37:09 sasd1 100 35.34 567 0 567 0.00 35.34 1 0 6
Average sasd1 100 35.39 568 0 568 0.00 35.39 1 0 6
#
Displaying all paths to a specific device (ioscan –m lun)
The new ioscan –m lun option provided by HP-UX 11i v3 allows you to display all the lunpaths
for a particular LUN on the system. This helps determine which tapes are accessible, through which
I/O ports, and displays all the lunpaths to each tape device. Displaying the lunpaths enables you to
copy and paste long lunpaths for use with scsimgr commands.
The following is an example of ioscan –m lun command output:
# ioscan -m lun /dev/rtape/tape12_BEST
Class I Lun H/W Path Driver S/W State H/W Type Health Description
======================================================================
tape 12 64000/0xfa00/0x18a estape CLAIMED DEVICE online HP
Ultrium 4-SCSI
0/3/0/0/0/1.0x500110a0008b9f72.0x0
0/3/0/0/0/1.0x500110a0008b9f73.0x0
0/7/0/0/0/1.0x500110a0008b9f72.0x0
0/7/0/0/0/1.0x500110a0008b9f73.0x0
/dev/rtape/tape12_BEST /dev/rtape/tape12_BESTn
/dev/rtape/tape12_BESTb /dev/rtape/tape12_BESTnb
#
Note
The tape device with a Persistent DSF of /dev/rtape/tape12_BEST has four lunpaths (two
beginning with 0/3/0… and two beginning with 0/7/0…) to the physical device. All are
represented with this single Persistent DSF.
Setting specific I/O path for tape devices (scsimgr get_attr / set_attr /
save_attr)
The scsimgr command on HP-UX 11i v3 is a very powerful management tool for monitoring and
managing storage connectivity of the server and for displaying various I/O metrics for connected
storage devices, including tape devices. Load balancing of I/O for tape devices is performed using
the “path lockdown” algorithm (using the lpt_lockdown device attribute), which automatically
balances lockdown of tape lunpaths across the available HBA ports.
In some cases, the default automatic load balance allocation of tape lunpaths across the available
I/O ports might not be optimal. You can override the default auto balancing of ”path lockdown” for