Hitachi TAGMASTORE MK-90RD011-25 - Manual (Page 357)

Hitachi Command Control Interface (CCI) User and Reference Guide 339
Condition Recommended Action
Sharing volumes in a hot
standby configuration
When paired volume is used for the disk shared by the hosts in hot standby configuration
using HA software, use the primary volume as the shared disk and describe the
corresponding hosts using the paired volume in the configuration definition file as shown
below. In the HA configuration, if a TrueCopy command issued by host C fails in host B
(because host B has gone down and/or IO_ERROR of the command device), host A is
connected and the command execution is retried.
Primary
volume
Secondary
volume
Host A Host B
Paired volume
HA
configuration Host C
Linkage with HA software The HORC Manager must not be an object of the process monitoring by the HA software
(cluster manager), because HORCM should run in the same level as the cluster manager.
Cooperation with HA software is done by activating the takeover command from the shell
script activated by the cluster manager in units of the package software.
Note: Cannot use a pair volume for the cluster lock disk which HA software uses for
election.
Maintenance Restart of HORCM is required if the storage system configuration is changed (e.g.,
microcode exchange, cache memory install/uninstall).
Hitachi TrueCopy only: In case of an error (e.g., single error in cache memory) which made
the pair volume is accompanied by maintenance work, the pairresync command or
paircreate command cannot execute copy rejection.
Command device Each Hitachi TrueCopy/ShadowImage command is executed by issuing a command to the
command device. The Hitachi TrueCopy/ShadowImage command is read or written from/into
the specific block area of the command device. Therefore, the command device cannot be
used by the user. In addition, this device must not belong to an LVM volume group. For
Windows systems, do not assign a drive letter to the command device to prevent utilization
by general users.
SCSI alternate path restrictions If the P-VOL and S-VOL are on the same server, alternate path from P-VOL to S-VOL
cannot be used. Use of SCSI alternate path to a volume pair is limited to among primary
(secondary) volumes. Alternate path using Hitachi Path Manager (Safe Path) is limited to
primary volumes.
Horctakeover (Swap-Takeover) When executing horctakeover on a standby server manually, I/O on the active server must
be stopped. When the package software goes for a standby server a failover by HA
software, the HA software must guarantee an I/O insulation of the active server.
HORCM failure to activate After a new system has been constructed, a failure to activate HORCM may occur due to
improper environmental setting and/or configuration definition by the user. Refer to the
HORCM activation log, and correct the setting(s).
Abnormal termination of
command
Refer to the command log file and HORCM log file to identify the cause of the error. If a
command terminates abnormally because of a remote server failure, recover the server from
the failure, then re-execute the command. If HORCM has shut down, restart HORCM. If an
unrecoverable error occurs, obtain the log files (see Table A.2) and contact the Hitachi Data
Systems Support Center.