Hitachi AMS 2000 Series, Reference Manual

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Troubleshooting
Hitachi AMS 2000 Family Command Control Interface (CCI) Reference Guide
General troubleshooting
If you have a problem with the CCI software, first verify that the problem is
not being caused by the UNIX or PC host hardware or software, and try
restarting the host. Table 2-5 provides operational notes and restrictions for
CCI operations.
For maintenance of ShadowImage, SnapShot, TrueCopy, and TCE volumes,
if a failure occurs, it is important to find the failure in the paired volumes,
recover the volumes, and continue operation in the original system.
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Table 2-5: CCI Operational Notes
Condition Recommended Action
Startup or shutdown
restrictions When the host starts, the primary volume host may update the secondary
volume. The secondary volume must not be mounted automatically in the
startup sequence. If the secondary volume is used by the LVM, the volume
group of the LVM must be deactivated. The secondary volume must be
mounted in the split state or in the simplex mode.
When the host starts, the secondary volume can be activated without
confirmation, once it can be guaranteed that the secondary volume has been
PSUS (Read/Write enable) or it is in the SMPL state during the host shutdown
sequence.
Hot standby operations CCI commands cannot execute hot standby operations between the primary
and secondary volumes. Use the takeover command intended for the HA
configuration to execute the hot standby operation. In hot standby operation,
two hosts are used, and the active (primary) and standby (secondary) host
programs are run alternately in each host in case one host fails. Follow these
precautions:
Operation across volumes. Since each CCI command causes the host
software to handle the volume by volume, a single volume should not be
partitioned to prevent it from being used by selected hosts.
Using LVM and paired volume together. When constructing the LVM on
the paired volume in the mutual hot standby configuration, the LVM logical
volumes must be constructed in units of volume to prevent the volumes from
being mounted by the LVM.
Coexistence of LVM
mirror and TrueCopy When the LVM mirror and TrueCopy volumes are used together, the LVM
mirror handles write errors and changes the volumes. Thus, the fence level
of the volumes used by the LVM mirror must be set to data.
Using paired volume in
a single host When constructing a paired volume in a single host, it is necessary to activate
two or more CCI instances. To activate two or more CCI instances, instance
numbers must be assigned using the environmental variable HORCMINST.
The HORCM and CCI commands must possess this environmental variable. A
configuration definition file and a log directory must be set for each instance.