Purpose

You should consider using this procedure under the following conditions:

• The current quorum disk is no longer available.
  
• The current quorum disk is unable to meet the performance requirements of the ARX system.
  
• You need to move the share for administrative purposes.

Prerequisites

You must meet the following prerequisites to use this procedure:

• Have administrative privileges on the ARX system
• Have a filer with a share prepared for Quorum disk usage

Description

The quorum disk is an NFS or CIFS share on any reliable, external filer. Each peer records its heartbeat messages on the quorum disk, and reads the heartbeat messages from the other. This is another path for reading the peer’s heartbeats, in addition to the path through the redundant-pair link. You may change the quorum disk that a high-availability pair of ARX systems uses, without requiring a maintenance window, failover, or interruption of service.

Procedures

Changing the quorum disk on both members of a high-availability pair

You use the quorum-disk command to change the quorum disk. To simultaneously change the quorum disk on both members of a high-availability pair, perform the following procedure:

Impact of workaround: This procedure is performed on both units at the same time. If an unexpected reload occurs while the switches are misconfigured, issues may occur due to both switches becoming active at the same time.

1. Open two separate terminal windows, and log in to the CLI on both ARX systems at once.
2. Enable privileged mode on both terminals by typing the following command in each terminal:

   enable

3. Verify that both ARX systems can reach the new quorum disks, using the following command syntax in each terminal:

   probe exports host <ip address> [user <username> windows-domain <domain-name>]

   Note: By default, the probe exports command uses anonymous credentials when probing the specified host. The user and windows-domain values are required only if anonymous access has been disabled on the host being probed.

   Replace <ip address> with the IP address of the filer that will host the new quorum disk share.
   
   For example:

   probe exports host 10.0.0.1

   Note: The probe exports command may take several minutes to complete.

   The command output appears similar to the following example:

   Export probe of filer "10.0.0.1"
   % INFO: Filer 10.0.0.1 does not support CIFS or is unreachable.
     
   CIFS Credentials: [anonymous]
   
   Security:
     NFS
       Path (Owner)                                 Access
       -------------------------------------------  -------------------------------
       /var/exports/quorum                          Mounted,rsize=32768,wsize=32768
       /var/exports/meta                            Mounted,rsize=32768,wsize=32768

   Important: Verify that the share you intend to use as your quorum disk is mounted in the probe exports output.

   Note: If you are using NFS for the quorum disk, you may disregard errors about CIFS support, and the other way around.

4. You must enter cfg-redundancy mode on both units. First, enable privileged mode by typing the following command in each terminal:

   enable

5. Enter configuration mode by typing the following command in each terminal:

   config

6. Enter redundancy configuration mode by typing the following command in each terminal:

   redundancy

   Both systems are now in cfg-redundancy mode.
7. Perform the appropriate quorum-disk command on both units.

   Important: Do not press Enter at this time.

   For example:

   quorum-disk 10.0.0.1:/var/exports/quorum nfs3

   Note: For more information, including the full syntax of the quorum-disk command, refer to the ARX CLI Reference Guide.

   Note: Prepare to perform Steps 8 and 9 simultaneously (or as close to one another as possible).

8. Press enter on the first terminal window.

   Note: It does not matter if the first terminal window in this context is the junior or the senior peer.

   A message that appears similar to the following example logs to the terminal:

   08-25 20:37:59 The configured quorum disk path differs on the peer switch. This should be corrected immediately.

9. Press enter on the second terminal window.
   
   A message that appears similar to the following example logs to syslog:

   08-25 20:38:08 Quorum disk paths now agree. [NetHb-58.1, 2f148bf7bb883ef81e9f536ca659920000000000]

10. To review the status of the Redundancy link, use the following command:

    show redundancy

11. Run the show redundancy command repeatedly on both units until the status of the quorum disk is verified as up.
    
    The command output appears similar to the following example:

                                                   Transitions
    Node Switch/Quorum Disk   Status     Role    Total Last (UTC)
    ---- -------------------- ---------- ------- ----- -------------------
     1   SupARX1k2a           Up         Active  1     20:36:25 08/25/2008
    *2   SupARX1k2b           Up         Backup  Never -
     QD  10.0.0.1             Up         Quorum  2     20:39:44 08/25/2008

    Note: The status may display as down for up to one minute. This behavior is expected. If the quorum disk share continuously fails to come up, open a case with F5 Technical Support.

12. Once the new quorum disk is verified as up from both units, the move of the quorum disk is complete.

Supplemental Information

• For more information on quorum disks and high-availability ARX system pairs, refer to the ARX CLI Network-Management Guide