Technical data

occurs because the Secure Path persistence module is loaded (at init level 1) only when the
LVM configuration is complete (before init level 1). Thevolumegroupsareactivatedby
Secure Path’s init script at init level 2.
• Concurrent or overlapping ioscans canresultinthefirst ioscan reporting intermediate path
states of the second ioscan. The second ioscan correctly reports the state of the paths. An
application doing ioscan compares could erroneously detect an error when another ioscan
begins.
• During an ioscan, sdisk drivers attach to swsp interface drivers instead of fcparray
(SCSI-3) or fcpdev (SCSI-2). Be c areful with applications that use ioscan output that
depends on the hardware tree that existed before installation of Secure Path.
• When a path to a device managed by LVM becomes unavailable because of a controller, path
link, switch, or HBA failure, you can delay the I/O requests by up to one m inute imm ediately after
the failure. As a result, the responsiveness of mirrored logical volumes may be affected briefly.
When a physical volume becomes unavailable, applications generally experience a delay while
an I/O request to that physical volume times out. By default, this delay is 30 seconds, but you
can change the delay time using the pvchange(1M) command.
• If you issue a read command, LVM selects another mirror and tries again.
• If you issue a write command, LVM records the error and continues, as long as the data has
been written successfully to at least one mirror.
In either case, with Secure Path installed, this initial timeout can take up to one m inute. LVM keeps
track of the physical volume status as Unavailable and future I/O requests do not experience
this delay.
NOTE:
Beforedeactivatingthevolumegroup,ensurethatalllogicalvolumesofthevolumegroupare
unmounted. See “Secure Path device path representation and usage”fordetails.
Secure Path Manager (spmgr)
The following problems may arise in spmgr for Active-Passive disk arrays:
• If there are several Secure Path devices configured on the system, the Secure Path startup services
can take longer because device scanning is initiated to synchronize Secure Path persistence data.
• If a preferred path to a device is in the Failed state, and you run a spmgr restore –d
device command, the command line displays the prompt only. The path remains in a Failed
state and no path change is made. This is the expected response to the command.
• The spmgr alias command is used to refer to a large cumbersome old name using a shorter or
clearer alias. Reversing the argument order in spmgr alias alias_name old_name results in
the alias replacing the old name. Any command using the old name results in an error. You must
delete the alias for the old n ame to work correctly.
• The spmgr alias command checks a table of reserved words to prevent you from using words
in an alias that would result in unexpected behavior. However, this list is not comprehensive. Be
careful to avoid using special characters that could be misinterpreted by the shell, such as a
leading “-” or “$.” The current list of reserved words maintained by spmgr are:
add alias client delete display help log notify on off password
prefer quiesce restart restore select set spmgr unalias unprefer
• The spmgr restore –r 0000-0000-0000-0000 command should produce an error for an
invalid WWNN, but instead it successfully restores all preferred paths on all attached arrays just
like the spmgr restore all command.
• Ifyouenableauto-restoreusingthespmgr set –a on command, and then select a new
path using the spmgr select -p path_instance command, the path remains selected
and will not be auto-restored. Auto-restore returns to the currently active path only if that path
has failed and has been repaired.
• The spmgr add any_arg any_arg W W LUNID command generates the following error m essage:
Lun should be 0-7
HPStorageWorksSecurePath3.0FServicePack3forHP-UX11iv1.0and11iv2.0
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