HP X.25/9000 User's Guide HP-UX 11i v3 (5900-1523, August 2011)
Fortunately SMH performs a thorough critical resource analysis automatically, and presents options
to you based on its findings. If you determine that critical resources will be affected by the procedure,
you could replace the card when the server is off-line, or if you must take action immediately, you
can use rad to attempt an on-line addition of a backup card and deletion of the target card.
Failover actions/single points of failure
In most cases, the system will automatically fail over to the alternate resource when a card is
suspended. However, some subsystems might require manual intervention. For example, the Logical
Volume Manager (LVM), will automatically redirect I/O for a temporarily disconnected disk resource
to a mirror, logging errors as it handles this situation.
• Along those lines, if the resource will be suspended for an extended period of time, a large
number of error log entries could result.
• In this type of situation, you may want to manually switch over to a mirror beforehand. When
you have completed the OLA/R procedure, the mirror and disk can be resynchronized.
If you suspend a card and the backup takes over, the system can contain a single point of failure.
If the backup resource fails before the new card is on-line, the system could potentially crash. This
window of vulnerability can be minimized by keeping the period of suspension as short as possible.
This requires careful planning, and gathering as much information as possible before actually
suspending driver operation and powering-down a card slot.
When an extended suspension period is unavoidable, or when the system is mission-critical, it is
desirable to configure a second backup resource if possible.
How to on-line replace (OLR) a J3525A PCI card using SMH
WARNING! When performing online replacement, the stack for all the ports of the interface card
under consideration will be stopped before replacement. They will be restarted after the replacement.
Thus any user application which has open connections will receive DISCONNECT messages. The
connections will have to be re-established after successful replacement of the interface card.
1. Start SMH.
2. From the SMH Areas screen, select PeripheralDevices.
3. From the PeripheralDevices screen, select Cards.
4. From the I/O Cards screen, view the list of available I/O cards. Select from the possible entries
mentioned below:
• HP J3525A PCI 2-port PSI card
5. From the Menu bar, select Actions.
6. From the Actions drop-down list, select Replace.
7. SMH now performs a Critical Resource Analysis (CRA). That is, now that you have selected
to Replace a card, SMH’s first step is to confirm that no critical resources will be disabled
when the card is taken off-line.
Output messages from the CRA process are presented in the Analyze Critical Resources screen
which will be shown before you can proceed. The messages displayed on this screen and the
availability to continue on from it (OK button activated) depend on the results of the analysis.
Table 17 Three possible critical resource analysis (CRA) outcomes
User ActionsButtons ActivatedScreen DisplaysNotesOutcome
Click Cancel to halt
the operation and
OK and Cancel“No affected
resources are critical
At this point, you can
still cancel the
replacement process.
No critical resources
identified.
cancel theor in-use” and
replacement with no“Critical Resource
How to on-line replace (OLR) a J3525A PCI card using SMH 73