I/O to the external volume from the open system host is in progress.

Stop I/O to the volume and un-mount the volume from the host.

Host I/O is forcibly stopped if you disconnect when I/O is in progress.

The external volume includes LDEVs used in pair operations with the following copy software products:

• ShadowImage
• Universal Replicator
• TrueCopy
• Thin Image
• Global-active device

Delete the pair.

You can disconnect without deleting a ShadowImage pair when pair status is PSUE or Suspend/SUSPER.

The external volume includes LDEVs registered to a Thin Image data pool.

Delete Thin Image data pool.

The external volume includes LDEVs registered to a Dynamic Provisioning pool volume (DP-VOL).

Perform all of the following operations on DP-VOLs associated with the external volume:

• Stop using the DP-VOLs.
• Use the Block LDEVs window to block the DP-VOLs.
• If the Data Direct Mapping attribute is enabled for the external volume, block only the related DP-VOL.

In addition, recover the path failure of the Pool VOL if the Pool VOL registered in the DP pool has a failure.

The external volume includes LDEVs for which Volume Migration processing is in progress.

Delete the migration plans.

The external volume is used in a global-active device quorum disk.

Delete the quorum disk settings.