394 IBM System Storage DS6000 Series: Copy Services with IBM System z
Example 26-52 shows the command that creates two FlashCopy relationships.
Example 26-52 mkflash to establish FlashCopy relationships for Global Mirror
dscli mkflash -record -nocp -cfg $DSCLI/profile/DS-02.profile 6500:6502 6501:6503
Date/Time: June 14, 2005 3:28:58 PM EDT IBM DSCLI Version: 5.0.3.134 DS: IBM.2107-7573731
CMUC00137I mkflash: FlashCopy pair 6500:6502 successfully created.
CMUC00137I mkflash: FlashCopy pair 6501:6503 successfully created.
To list the new FlashCopy pairs, use the command lsflash as described in 26.11.3, “Query
FlashCopy pairs” on page 396.
26.10.5 Create and start the Global Mirror session
For the creation of a Global Mirror session we have the DS CLI command mksession. This
command defines a session number and populates the Global Mirror session with Global
Copy source volumes.
Issue the following command to each LSS that has potential Global Mirror volumes:
dscli mksession -lss <LSS_ID> -cfg <Device configuration file> -volume <Volume>
<Volume> ... <Session_Number>
Example 26-53 illustrates how to create Global Mirror session number 01 for LSS 65 and add
two Global Copy source volumes to this session.
Example 26-53 mksession to create a session and add two volumes
dsscli mksession -lss 65 -volume 6500-6501 -cfg $DSCLI/profile/DS-01.profile 01
Date/Time: June 14, 2005 3:29:46 PM EDT IBM DSCLI Version: 5.0.3.134 DS: IBM.2107-7506551
CMUC00145I mksession: Session 01 opened successfully.
Note that this command only adds volumes to the newly defined session number 01. It does
not start the Consistency Groups formation process.
To list the session status, use the lssession command, which is described in 26.11.4, “Query
volumes in the session” on page 396.
To start the Consistency Groups formation process, start the Global Mirror session. For this
use the mkmir command. Also, when more than one storage disk subsystem participates with
its primary volumes in a common Global Mirror session, you have to specify topology
information in the command that starts the Global Mirror session.
The mkmir command has the following syntax:
dscli mkgmir -lss <Master LSS ID> -cginterval <Number of seconds> -coordinate
<Number of milliseconds> -drain <Number of seconds> -session <Session_ID> -cfg
<Master device configuration file>
<Master_Control_Path_LSS_ID>:<Subordinate_Control_Path_LSS_ID> ...
The following tuning parameters can be set at this time with the command:
cginterval - Specifies how long to wait between the formation of Consistency Groups. If
this number is not specified or is set to zero, then Consistency Groups are formed
continuously.
coordinate - Indicates the maximum time that Global Mirror processing queues host I/Os
when Global Mirror starts to form a new Consistency Group. The default is 50 ms.