HP-UX 11i v3 Native Multi-Pathing for Mass Storage (August 2012)

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Class I H/W Path Driver S/W State H/W Type Description
…
lunpath 16 0/2/1/0.0x500508b3009097f1.0x4014000000000000 eslpt NO_HW LUN_PATH
LUN path for disk17
lunpath 5 0/2/1/0.0x500508b3009097f9.0x4014000000000000 eslpt NO_HW LUN_PATH
LUN path for disk17
lunpath 22 0/4/1/0.0x500508b3009097f1.0x4014000000000000 eslpt CLAIMED LUN_PATH
LUN path for disk17
lunpath 13 0/4/1/0.0x500508b3009097f9.0x4014000000000000 eslpt CLAIMED LUN_PATH
LUN path for disk17
# dd if=/dev/rdsk/c5t2d4 of=/dev/null count=120
/dev/rdsk/c5t2d4: No such device or address
dd: cannot open /dev/rdsk/c5t2d4
The dd command cannot open /dev/rdsk/c5t2d4.
The following sequence shows how changing leg_mpath_enable while /dev/rdsk/c5t2d4 is
open does not affect the lunpaths used for I/O transfer on /dev/rdsk/c5t2d4 as long as it remains
opened.
1. Show current value of leg_mpath_enable for disk17, as follows:
# scsimgr get_attr -D /dev/rdisk/disk17 -a leg_mpath_enable
SCSI ATTRIBUTES FOR LUN : /dev/rdisk/disk17
name = leg_mpath_enable
current = true
default = true
saved =
2. Clear the statistics, as follows:
# scsimgr clear_stat -D /dev/rdisk/disk17 all_lpt
scsimgr: Cleared statistics successfully
# scsimgr get_stat –D /dev/rdisk/disk17 all_lpt | grep "Total I/Os processed"
Total I/Os processed = 0
Total I/Os processed = 0
Total I/Os processed = 0
Total I/Os processed = 0
3.
Open /dev/rdsk/c5t2d4 and transfer data, as follows:
# dd if=/dev/rdsk/c5t2d4 of=/dev/null count=100000000 &
[1] 17998
#
# scsimgr get_stat -D /dev/rdisk/disk17 all_lpt | grep "Total I/Os processed”
Total I/Os processed = 18071
Total I/Os processed = 17988
Total I/Os processed = 17988
Total I/Os processed = 17988
4.
Set leg_mpath_enable to false while /dev/rdsk/c5t2d4 is open, as follows:
# scsimgr set_attr -D /dev/rdisk/disk17 -a leg_mpath_enable=false
Value of attribute leg_mpath_enable set successfully
# scsimgr get_attr -D /dev/rdisk/disk17 -a leg_mpath_enable
SCSI ATTRIBUTES FOR LUN : /dev/rdisk/disk17
name = leg_mpath_enable
current = false
default = true
saved =
5.
Verify whether I/O transfers are performed on all lunpaths of disk17 even if multi-pathing is
now disabled for legacy DSFs of disk17, as follows:
# scsimgr get_stat -D /dev/rdisk/disk17 all_lpt | grep "Total I/Os processed”
Total I/Os processed = 73881
Total I/Os processed = 73780