CP Redundancy fails when disk partition schemes are mismatched on CPM-8600s

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Article ID: 168107

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Updated On:

Products

XOS

Issue/Introduction

This article describes a workaround and a solution for an issue in which CP Redundancy fails because hard disk partition schemes are mismatched on CPM-8600s.CP-Redundancy will fail on a CPM-8600 when adding or replacing a CPM-8600 if the hard disk partition sizes on the new secondary CPM do not match those configured on the primary CPM-8600. When this happens, the new CPM-8600 transitions to Offline instead of synchronizing with the primary and becoming secondary. This condition causes the following error message to display on the console during boot up:

------- waiting for result of election
Election done... transition to REPAIR

**** Attention administrator: Disk partitions on this CP
are different from those of Primary CP and cannot be mirrored.
This CP will go to Offline now to be fixed....


In some cases, this message may not display during boot up. However, the message can also be found in the /crossbeam/logs/cbscprmd.log file on the offline CPM-8600:

Nov 17 13:35:39 [I] int CCprm::ComparePartInfo (part_info_t *, unsigned int)
mirror partition size mismatched: local dev=md6 size=4016000, remote dev=sda6 size=1004031
Nov 17 13:35:39 [F] int CCprm::ProcessMidInfoMsg (mirror_info_t *)
**** Attention administrator: Disk partitions on this CP
are different from those of Primary CP and cannot be mirrored.
This CP will go to Offline now to be fixed....
Nov 17 13:35:40 [I] void CCprm::OfflineState () Node state changes REPAIR -> OFFLINE

Cause

Problem: Crossbeam supports either an 80 GB or 120 GB partition scheme on the CPM-8600, for both non-RAID and RAID configurations. In order for CP Redundancy to work, the partition schemes must be identical on both CPM-8600s.

Resolution

Crossbeam recommends that you perform a clean installation with Install Server V6.0 or later and choose the partition scheme that matches the primary CPM when prompted during the installation procedure:

The hard drive(s) on this CPM can be partitioned as either 120GB or 80GB.
If you plan to use CPM Redundancy feature, please make sure that the partition
sizes on both CPMs are the same.


Enter the appropriate scheme when the following question appears:

Which partition scheme would you like to use (120 | 80) ?

Workaround

Crossbeam has developed a utility that converts a 120 GB partition scheme to an 80 GB partition scheme. This utility over-writes the existing partition scheme on an offline CPM.

Important: Before you run the partition conversion utility, note the following considerations:

  • Crossbeam recommends that you perform this procedure from the console and log the output to a file.
  • You can only use this utility to resize the disk partition size on an offline CPM from 120 GB to 80 GB. To determine the disk partition size on a CPM, do the following:

a)    From the Unix prompt, run cat /proc/partitions and look at the #blocks

b)    Look at the lines for sda6, sda8, sda11, and sda13. If the CPM has a dual disk configuration, also look at the lines for sdb6, sdb8, sdb11, and sdb13.

For disks with a 120 GB partition size, the output appears as follows:
major minor  #blocks  name
   8     6    2008093 sda6
   8     8   40001818 sda8
   8    11    2008093 sda11
   8    13   40001818 sda13
 
For disks with an 80 GB partition size, the output appears as follows:
major minor  #blocks  name
   8     6    1004031 sda6
   8     8   28001263 sda8
   8    11    1004031 sda11
   8    13   28001263 sda13
  • You must configure a management port on the offline CPM in order use the partition conversion procedure.

Running the partition conversion utility

1.   Go to /crossbeam/bin directory and determine if the partition_resize.shar file is present. If it is present, go to step 5. If the file is not present, continue with step 2.

2.   Download the partition conversion utility file partition_resize.shar.gz from the Crossbeam Customer Support portal (http://www.crossbeam.com/support/online-support/). You must have a valid support account to access the portal. See References, below, for a link to the partition conversion utility.

3.   After downloading the file, transfer it to the Offline CPM.

4.   At the Linux prompt, extract the utility using the following command:

tar –xzvf partition_resize.shar.gz
 
5.   Configure the CPM to be Offline on next reboot using the following commands:

CBS# configure cp-redundancy set this_cp offline

CBS#
wr
 
6.   Execute the utility at the Linux prompt using the following command:

./partition_resize.shar
 
Note: If the CPM is not set to be offline on the next reboot, the utility displays a message to that effect, and exits. You must perform step 5 and then execute the utility again.

Note: If the CPM disk drive has 80 GB partition size when the utility starts, it will exit without resizing the partitions, displaying a message to that effect.

7.   The partition_resize.shar script will then automatically resize the partitions on the offline CPM to match that of the primary CPM. During this process the system will reboot a total of 3 times. When the script has completed successfully the login prompt will appear. After logging in the following message will display for 1 hour:

XOS login: admin
Password:
Last login: Tue Nov 17 12:45:33 on ttyS0
Partition resize completed successfully.
Remove /etc/motd to get rid of this message
Information was last updated on Tue Nov 17 12:03:06 EST 2009


The following log entry is written to /var/log/messages:

Dec  1 11:02:07 XOS partition_resize: Partition resize completed successfully

8. The CPM-8600 is now ready to synchronize with the running Primary CPM. To do so, execute the following commands on the Offline CPM:

CBS# configure cp-redundancy set this_cp election

CBS# wr

CBS#
reload all
 
9.  Verify that the CPM-8600s begin the synchronization process.