PRIMEQUEST System Disk Mirror for Windows User's Guide V1.0

1.5 Mirror Group States

The typical mirror group states are as follows.

 

The state before mirror group creation

Before creating a mirror group, you must create partitions on the mirror source disk and remove all partitions from the mirror destination disk.

[Figure 1_10: Before mirror group creation]

 

The state after mirror group creation

After a mirror group is created, synchronization copying from the mirror source disk to the mirror destination disk is performed, and the mirroring state of the disks is established when the copy is completed. The mirror source disk will be the master disk and also the read disk and the mirror destination disk will be the sub disk.

[Figure 1_11: After mirror group creation]

 

The state when booted from the mirror destination disk

When the system is booted from the boot disk's mirror destination disk, the mirror destination disk will be the master disk and also the read disk and the mirror source disk will be the sub disk.

[Figure 1_12: When booted from the mirror destination disk]

 

The state after sub disk I/O error occurrence

If an I/O error occurs on the sub disk, the sub disk will be a non-mirrored disk as an ERROR disk.

[Figure 1_13: After sub disk I/O error occurrence]

 

The state after sub disk removal

If the sub disk is removed from the mirror group, sub disk partitions are removed and the sub disk will be a non-mirrored disk.

[Figure 1_14: After sub disk removal]

The state after master disk I/O error occurrence

If an I/O error occurs on the master disk, the sub disk will be the read disk and the master disk will be a non-mirrored disk as an ERROR disk. If the system is rebooted in this state, the sub disk will be the new master disk.

[Figure 1_15: After master disk I/O error occurrence]

 

The state after master disk removal

If the master disk is removed from the mirror group, the sub disk will be the read disk and the master disk will be a non-mirrored disk. In this event, the system will be rebooted automatically, and the previous master disk's partitions are removed. After the reboot, the sub disk will be the new master disk.

[Figure 1_16: After master disk removal]

The read disk
The read disk is also the master disk under normal conditions. However, the sub disk will be the read disk:

• If an I/O error occurs on the master disk when the sub disk is VALID
  

• During the period before the system reboot after the master disk removal