N+M Cold Standby - Hitachi Compute Blade 2000 User Manual

N+M Cold Standby

When using a non-standby partition as a standby partition, follow the steps below:

1 Back up configuration information on a non-standby partition using the UBR
command of SVP command mode.
2 Configure the non-standby partition to a standby partition, and build N+M cold
standby for operation.
When using a standby partition as a non-standby partition, follow the steps below:

1 Configure a standby partition to a non-standby partition to release the N+M cold
standby.
2 Configure the non-standby partition to the LP mode and start it.
3 If some configuration is backed up, finish LPAR manager and restore the
configuration using the UBR command of SVP command mode.
If you do not follow the steps above, more than one WWN or
MAC address can exist and can cause serious problems.
Make sure to use the steps above.
Time Setting in Switchover and
Recovery with N+M Cold Standby
This subsection describes the time setting in switchover and recovery in N+M cold
standby environment.
Problem

Time difference might occur when switchover or recovery occurs in the N+M cold
standby environment due to the difference for BIOS time in specifications on the
OS.
This problem might occur if all the following three conditions are satisfied.

(1) The Compute Blade System uses the N+M cold standby function.
(2) The following OSs shown in (a) and (b) are mixed in the same N+M cold
standby group.
(a) OSs that recognize BIOS time as local time
Windows
 ........
Red Hat Enterprise Linux with Local time as a setting value
 ........
(b) OSs that recognize BIOS time as UTC
Red Hat Enterprise Linux with UTC as a setting value
 ........
(3) An active server blade with (a) running is switched to a standby server blade
with BIOS time as UTC, or the former active server blade is switched back.
Or an active server blade with (b) running is switched to a standby server
blade with BIOS time as local time, or the former active server blade is
switched back.
(4) For standard server blade X55R4 model, RTC time synchronization is
disabled. If N+M group includes LPAR manager, RTC time synchronization is
not available. See "RTC time Synchronization at N+M Cold Standby Failover"
in Chapter 13 for details.
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