Description : Procedure for Creating True Copy pairs in Hitachi

Platform : Hitachi

Model : AMS 2100/2300/2500

Category : Configuration

Problem : Procedure for Creating True Copy pairs in Hitachi

Prerequisites

• Logical units for the primary and secondary volumes must be created and formatted. They must have identical block counts.

• Logical units for volumes to be paired must be in Simplex status. • DM-LUs must be set up.

Create Pair Process A TrueCopy pair consists of primary and secondary volume whose data stays synchronized until the pair

is split. During the create pair operation, the following takes place:

• All data in the local P-VOL is copied to the remote S-VOL.

• The P-VOL remains available to the host for read/write throughout the copy operation.

• Pair status is Synchronizing while the initial copy operation is in progress.

• Status changes to Paired when the initial copy is complete.

• New writes to the P-VOL continue to be copied to the S-VOL in the Paired status.

Procedure: Step 1: To create a pair In the Navigator 2 GUI, click the check box for the local array, then click the

Show & Configure Array button.

Step 2: In the navigation tree, click Replication, then click Remote Replication. The Remote Replication

screen displays.

Step 3: Click the Create Pair button. The Create Pair screen displays.

Step 4: Enter a Pair Name, if desired. Omitting the pair name results in a default name created for you

(which can be changed via the Edit Pair screen).

Step 5: Select the LUN to become the P-VOL.

Step 6: Enter the LUN for the S-VOL. Keep in mind that the P-VOL and S-VOL must have matching sizes.

Step 7: Click the Advanced tab.

Step 8: From the Copy Pace dropdown list, select the speed at which copies will be made. Select Slow,

Medium, or Fast.

Step 9: In the Group Assignment area, you have the option of assigning the new pair to a consistency

group. Do one of the following:

• If you do not want to assign the pair to a consistency group, leave the Ungrouped button

selected.

• To create a group and assign the new pair to it, click the New or existing Group Number button

and enter a new number for the group in the box.

• To assign the pair to an existing group, enter its number in the Group Number box, or enter the

group name in the Existing Group Name box.

Step 10: In the Do initial copy from the primary volume field, leave Yes checked to copy the primary to

the secondary volume.

Step 11: Select a Fence Level of Never or Data.

Step 12: Click OK.

Step 13: Check the Yes, I have read message then click Confirm.

Step 14: Click Close on the success message.

Best Practice’s

The create pair and resynchronize operations affects performance on the host. Therefore:

Perform the operation when I/O load is light.

Limit the number of pairs that you create simultaneously within the same RAID group to

two.

If a TrueCopy pair is cascaded with ShadowImage, and the pair of one or the other is in

Paired or Synchronizing status, place the other in Split status for performance reasons.

If you have two TrueCopy pairs on the same two arrays and the pairs are bi-directional, that

is, a local and remote volume on each array, perform copy operations at different times to

avoid performance slow-down.

Monitor write-workload at the remote array as well as on the local array. Performance on

the remote array affects performance on the local array, since TrueCopy operations are

slowed down by

unrelated remote operations. Performance backup reverberates across the two systems.

Use a copy pace that matches your priority for either performance or copy time.