Migrating from disk-based to server-based fencing in an online cluster
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Migrating from disk-based to server-based fencing in an online cluster

You can either use the installer or manually migrate from disk-based fencing to server-based fencing without incurring application downtime in the VCS clusters.

See About migrating between disk-based and server-based fencing configurations.

You can also use response files to migrate between fencing configurations.

See Migrating between fencing configurations using response files.

Warning:

The cluster might panic if any node leaves the cluster membership before the coordination points migration operation completes.

This section covers the following procedures:

Migrating using the script-based installer

See “To migrate from disk-based fencing to server-based fencing using the installer”.

Migrating manually

See “To manually migrate from disk-based fencing to server-based fencing”.

To migrate from disk-based fencing to server-based fencing using the installer

  1. Make sure system-to-system communication is functioning properly.
  2. Make sure that the VCS cluster is online and uses disk-based fencing.
    # vxfenadm -d

    For example, if VCS cluster uses disk-based fencing:

    I/O Fencing Cluster Information:
================================
Fencing Protocol Version: 201
Fencing Mode: SCSI3
Fencing SCSI3 Disk Policy: dmp
Cluster Members:
		* 0 (galaxy)
		1 (nebula)
RFSM State Information:
		node 0 in state 8 (running)
		node 1 in state 8 (running)
  3. On any node in the cluster, start the installvcs program with the -fencing option.
    # /opt/VRTS/install/installvcs -fencing

    The installvcs program starts with a copyright message and verifies the cluster information.

    Note the location of log files which you can access in the event of any problem with the configuration process.

  4. Confirm that you want to proceed with the I/O fencing configuration.

    The installer verifies whether I/O fencing is configured in enabled mode.

  5. Confirm that you want to reconfigure I/O fencing.
  6. Review the I/O fencing configuration options that the program presents. Type 4 to migrate to server-based I/O fencing. 
    Select the fencing mechanism to be configured in this
Application Cluster [1-4,q] 4
  7. From the list of coordination points that the installer presents, select the coordination points that you want to replace.

    For example:

    Select the coordination points you would like to remove
from the currently configured coordination points:
   1) emc_clariion0_62
   2) emc_clariion0_65
   3) emc_clariion0_66
   4) All
   5) None
   b) Back to previous menu
Enter the options separated by spaces: [1-5,b,q,?] (5)? 1 2

    If you want to migrate to server-based fencing with no coordinator disks, type 4 to remove all the coordinator disks.

  8. Enter the total number of new coordination points.

    If you want to migrate to server-based fencing configuration with a mix of coordination points, the number you enter at this prompt must be a total of both the new CP servers and the new coordinator disks.

  9. Enter the total number of new coordinator disks.

    If you want to migrate to server-based fencing with no coordinator disks, type 0 at this prompt.

  10. Enter the total number of virtual IP addresses or host names of the virtual IP address for each of the CP servers.
  11. Enter the virtual IP addresses or host names of the virtual IP address for each of the CP servers.
  12. Verify and confirm the coordination points information for the fencing reconfiguration.

  13. Review the output as the installer performs the following tasks:

    • Removes the coordinator disks from the coordinator disk group.

    • Updates the application cluster details on each of the new CP servers.

    • Prepares the vxfenmode.test file on all nodes.

    • Runs the vxfenswap script.

      Note the location of the vxfenswap.log file which you can access in the event of any problem with the configuration process.

    • Completes the I/O fencing migration.

  14. If you want to send this installation information to Symantec, answer y at the prompt.
    Would you like to send the information about this installation
to Symantec to help improve installation in the future? [y,n,q,?] (y) y
  15. After the migration is complete, verify the change in the fencing mode.
    # vxfenadm -d

    For example, after the migration from disk-based fencing to server-based fencing in the VCS cluster:

    I/O Fencing Cluster Information:
================================
Fencing Protocol Version: 201
Fencing Mode: Customized
Fencing Mechanism: cps
Cluster Members:
		* 0 (galaxy)
		1 (nebula)
RFSM State Information:
		node 0 in state 8 (running)
		node 1 in state 8 (running)
  16. Verify the current coordination points that the vxfen driver uses.
    # vxfenconfig -l

To manually migrate from disk-based fencing to server-based fencing

  1. Make sure system-to-system communication is functioning properly.
  2. Make sure that the VCS cluster is online and uses disk-based fencing.
    # vxfenadm -d

    For example, if VCS cluster uses disk-based fencing:

    I/O Fencing Cluster Information:
================================
Fencing Protocol Version: 201
Fencing Mode: SCSI3
Fencing SCSI3 Disk Policy: dmp
Cluster Members:
		* 0 (galaxy)
		1 (nebula)
RFSM State Information:
		node 0 in state 8 (running)
		node 1 in state 8 (running)

  3. Make sure that you performed the following tasks on the designated CP server:

    • Preparing to configure the new CP server.

    • Configuring the new CP server

    • Preparing the new CP server for use by the VCS cluster

    See the Veritas Cluster Server Installation Guide for the procedures.
  4. Create a new /etc/vxfenmode.test file on each VCS cluster node with the fencing configuration changes such as the CP server information.

    Refer to the sample vxfenmode files in the /etc/vxfen.d folder.

  5. From any node in the VCS cluster, start the vxfenswap utility:
    # vxfenswap [-n]

  6. Review the message that the utility displays and confirm whether you want to commit the change.

    • If you do not want to commit the new fencing configuration changes, press Enter or answer n at the prompt.

      Do you wish to commit this change? [y/n] (default: n) n

      The vxfenswap utility rolls back the migration operation.

    • If you want to commit the new fencing configuration changes, answer y at the prompt.

      Do you wish to commit this change? [y/n] (default: n) y

      If the utility successfully commits, the utility moves the /etc/vxfenmode.test file to the /etc/vxfenmode file.

  7. After the migration is complete, verify the change in the fencing mode.
    # vxfenadm -d

    For example, after the migration from disk-based fencing to server-based fencing in the VCS cluster:

    I/O Fencing Cluster Information:
================================
Fencing Protocol Version: 201
Fencing Mode: Customized
Fencing Mechanism: cps
Cluster Members:
		* 0 (galaxy)
		1 (nebula)
RFSM State Information:
		node 0 in state 8 (running)
		node 1 in state 8 (running)
  8. Verify the current coordination points that the vxfen driver uses.
    # vxfenconfig -l
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