Copying source to intermediate tape

For an initial, baseline transfer for a SnapMirror relationship, you might want to do the transfer using a tape. To do this, you first need to copy the base data to tape.

Steps

1. If you do not know whether the disk geometries (that is, the size and number of disks) of the source volume and the ultimate destination volume match, use the snapmirror retrieve -g command to determine if this is so.

   In the consoles of both the source and destination storage systems, enter the following command: snapmirror retrieve -g vol_name

   For both the source and the destination volume, the system displays the number and block size of the disks it includes.

   Example

   A return value of 7200000x10 7000x10 means that the specified volume consists of 10 disks of 720,000 blocks and 10 disks of 7,000 blocks.

   • The most desirable result is for the source and destination volume disk geometries to match.
   • If the geometries do not match, record the disk geometry of the destination volume for later use.

2. At the source system, load the tape into a local attached tape device.
3. At the source system, start the data transfer to tape by entering the following command: snapmirror store [-g dest_disk_geom] source_volume dest_tapedevices

   -g dest_disk_geom applies if the disk geometry of the destination volume, as determined in Step 1, is different from the disk geometry of the source volume. If they are different, use the -g parameter to specify the destination volume disk geometry.

   Example

   -g 140000x10,7000x10

   source_volume is the volume you are copying.

   dest_tapedevices is a comma-separated list of tape devices to which you are copying the volume.

   Example

   snapmirror store -g 14000x10,7000X10 vol2 nrst0a,rst1a

   SnapMirror starts transferring data to tape. This command creates a baseline transfer. If you have to use more than one tape, SnapMirror prompts you for another tape.

4. If SnapMirror prompts you for another tape, add another tape to the drive, and continue transfer of data to tape by entering the following command:snapmirror use dest_tapedevices tape_drive

   dest_tapedevices is the tape device or a comma-separated list of tape devices to which you are copying the volume.

   tape_drive is the drive holding the new tape you supplied.

   Note: The snapmirror use command does not support copying qtrees from tape. If you specify a qtree path as the source or destination, SnapMirror returns an error message.

5. Repeat the previous step until SnapMirror finishes copying the volume to tape.