Removing volumes from a session (Global Mirror)

Complete this task to remove volumes from a Global Mirror session. This task is also the first step in removing the Global Mirror environment from your system.

Ensure that you have closed the Global Mirror sessions associated with the Global Mirror environment if you are processing this task as part of removing the Global Mirror environment from your system.

This task covers two circumstances

removing volumes from a session without removing the session from Global Mirror processing
removing all volumes from each session as part of the steps for removing the Global Mirror environment from your system.

You can remove Global Copy primary volumes from a Global Mirror session at any time after the Global Mirror session has started without stopping the session.

If you have many volumes that you want to remove from a Global Mirror session, you might consider removing them from the session in stages. This lessens the impact on your processing. If you intend to use the volumes in a different configuration, you must remove the pair and path associations. Removing a volume from a Global Mirror session does not remove the pair and path associations.

Perform the following steps to remove volumes from a Global Mirror session. The example commands in this task are shown in two formats. The first format shows the type of information that the command requires. The second format provides the command with declared values for the variables.

Issue the lssession command to query the status of all volumes that are associated with the sessions of a specified logical subsystem. Enter the lssession command at the dscli command prompt with the following parameters and variables:
dscli>lssession –dev storage_image_ID -l LSS_ID
```
dscli>lssession –dev IBM.1750-68FA120 -l 01
```
When you use the -l parameter, a detailed report displays a list of Global Mirror sessions for the specified logical subsystem (LSS) and information about the volumes of each session in the list.
Analyze the report and determine which volumes that you want to remove.
Issue the chsession command to remove the specified volumes from the specified Global Mirror session. Enter the chsession command at the dscli command prompt with the following parameters and variables:
dscli>chsession -dev storage_image_ID -lss LSS_ID -action remove -volume volume_ID session_ID

Example
```
dscli>chsession -dev IBM.1750-68FA120 -lss 10 -action remove 
-volume 0100-010F,0180-018F,0120 01
```
A confirmation message indicates that the session has been modified successfully.
Note: A volume ID range is defined by two volume IDs that are separated by a hyphen. Multiple volume IDs or volume ID ranges must be separated by a comma.

After the volumes have been removed from the Global Mirror session, you must end the volume associations for the removed volumes (FlashCopy, Global Copy pair, and remote mirror and copy path) if you plan to use the volumes in a different configuration.