ExpressCluster X 2.0 for Windows Reference Guide - Nec

Section III Maintenance information
Connecting mirror disks/hybrid disks manually
As for hybrid disk resources, if the above is performed while another server in the same server
group is using the shared disk, the data on the shared disk may be destroyed. Make sure to stop
the other server or disconnect the disk cable of the other server when you perform the above.
Recovering from mirror breaks
When the auto-mirror recovery is enabled, no special operation is required. Mirroring is
automatically recovered. However, if mirroring needs to be recovered forcibly, execution of a
command or operations for forcible mirror recovery using the WebManager are required.
If the auto-mirror recovery is disabled, you have to recover mirroring by executing a command or
using the WebManager.
The difference mirror recovery function is disabled and full copy is performed in the following
cases:
• When the partition configuration for mirror disk resource or hybrid disk has been changed
due to disk replacement etc.
• When both servers fail at the same time while mirror disk resource is normally activated
• When the current servers (servers updating and managing the disk in the server group) in
the both server groups fail at the same time when the hybrid disk resource is normally
activated
• When difference information could not be written successfully due to disk failure etc.
Automatically recovering from mirroring
When the auto-mirror recovery is enabled, mirroring is automatically recovered under the
following conditions:
1. Mirror disk resource or hybrid disk resource is active.
2. The server where mirror disk resource or hybrid disk resource is activated contains the latest
data.
3. Servers in the cluster are in the normal status, and you can verify their mirroring statuses.
4. The data among the servers is not the same.
The auto-mirror recovery is not performed if any of the following applies.
1. One of the servers (for hybrid disk resource, all servers in one of the server groups) is not
started.
2. You cannot confirm the mirroring status of the other server.
3. There is no server whose mirror status is normal.
781