TimeFinder (W2K)

Summary:

In this exercise, students will explore the Logical Volume Manager considerations when making File system data available that have been copied to BCVs on a backup host from Standard Volumes on a production host using Basic disks. The process of establishing a BCV pair copies all data from the Standard Volume to the BCV, including the signatures and MBRs. LDM databases from dynamic disks also copy, if originally resident on the standard volumes.

Objectives:

a)    Establish BCVs with Standard Volumes and verify that they are fully synchronized.

b)    Split the BCVs and the Standard Volumes.

c)     Make the data on the BCVs available to the backup host.

d)    Re-establish the BCVs and the Standard Volumes.

Note: If a production server owns both the standard and BCV volumes, you will not be able to successfully mirror the standard volume(s) which are dynamic disks to the BCVs on the same host. The reason is that this results in the BCV disk not being uniquely identified to the Operating System. Procedures required to resolve this duplication are not possible at the present time for Dynamic Disks. Such a mirror causes the BCV to fail to import as a foreign disk. You will be forced to “revert to basic disk” for this volume, effectively loosing access to all data on the disk.  It is generally necessary to have a backup host when mirroring data between standards and BCVs on Windows 2000 hosts.

This exercise builds on the previous exercises so first we will confirm that the filesystem and data created in the last step of TimeFinder Lab 1, are available.

1.   Verify that the drive letter you created in the previous exercise is available.

2.   Verify that the SYMCLI Device Group contains the correct devices.

a)     Use the following SYMCLI commands to list and verify the Device Group you created in the previous exercise.
# symdg list
# symdg show mystddg | more

b)     Verify that the associated BCVs are available to your host.
# symbcv list pd

c)      Check the environment variables for SYMCLI and if necessary set the SYMCLI_DG variable to your device group.  Note: Variables are case sensitive.
# symcli –def
# SYMCLI_DG=mystddg
# set SYMCLI_DG

3.   Establish, synchronize, and split your BCVs. Stop all activity to the Standard Volumes before the split to ensure a complete and consistent copy on the BCVs. In Windows 2000, you can remove the drive letter on a partition to stop I/O and flush file system buffers. Another method is to use EMC’s symntctl.exe tool, as in the following: symntctl umount –drive “letter”

a)     Ensure that the BCVs are not already established and synchronized, if not perform an establish operation now, else go to step 3(c). Remember to stop any processes and unmount any drive letters associated with partitions on the BCVs using the following commands from the SIU – CLI:

Stop I/O to the BCV volumes by removing their drive letters.

NOTE: You should run the symntctl openhandle command first here:

            symntctl openhandle –drive “drive_letter”

             It is recommended for scripting to echo the return code. If the code is #2 then there are openhandle processes on the drive.

Now dismiss the BCV volumes cache

            symntctl umount –drive “drive_letter” : -fs

Lastly, Unmount the BCV drive letter

                                symntctl umount –drive “drive_letter”

# symmir –full establish -nop

b)     Verify that BCV is fully synchronized.
# symmir query –i 10

   Or

  # symmir verify –synched –i 10

c)      The best procedure before splitting the Standard from the BCV is to stop I/O to the standard volumes by removing their drive letters as you did in step a) above and in the following.

NOTE: You should run the symntctl openhandle command first here:

            symntctl openhandle –drive “drive_letter”

             It is recommended for scripting to echo the return code. If the code is #2 then there are openhandle processes on the drive.

Now dismiss the BCV volumes cache

            symntctl umount –drive “drive_letter” : -fs

Lastly, Unmount the BCV drive letter

                                symntctl umount –drive “drive_letter”

            If the Standard cannot come off line then you can simply flush the file system buffers against the volume using the following

                        symntctl flush –drive “drive_letter”

Be aware that this will not cause a flush of application buffers – only file system buffers.

d)     Split the Standard Volumes and the BCVs.
# symmir split

4.      On the backup host, mount the BCV volumes.

5.      Use Windows Explorer on the Backup host to confirm that the data was copied.

Exercise wrap-up:
If you want to re-establish the BCVs to the Standard Volumes saving the changes made on the standards, what steps would you have to follow?

_______

If you again split the BCVs and wanted to make them available, what steps would you have to follow?
_______

If you want to re-establish the BCVs to the Standard Volumes saving the changes made on the BCVs, what steps would you have to follow?
_______

This concludes the TimeFinder Lab 2 (W2K). Please unmount your file systems, removing the drive letters, and delete the SYMCLI Device Group mystddg.

1.                    symdg –force delete mystddg

Good Luck!