Validating and Recovering Redundant SRP File Integrity

Note: The information in this section does not apply to the ERX-310 router, which does not support SRP module redundancy.

Even when flash cards on the primary and redundant SRP modules are synchronized, differences can exist in the content of files that reside on the primary flash card and the redundant flash card. You can use the flash-disk compare command to detect these differences so you can validate and, if necessary, recover the file integrity of the redundant SRP module.

The flash-disk compare command validates only those files that are synchronized between the primary and redundant SRP modules. It does not compare files that are normally excluded from the synchronization process, such as log files and core dump files. The command uses a simple checksum error detection algorithm to compare the contents of a file residing on the flash card of the primary SRP module with the contents of the same file residing on the flash card of the redundant SRP module.

To validate and recover redundant SRP file integrity:

1. Ensure that the file systems on the primary flash card and the redundant flash card are synchronized. (See Synchronizing Flash Cards for details.)
2. Issue the flash-disk compare command, specifying whether to perform the checksum validation for all files in NVS or only for configuration files.

   host1#flash-disk compare all

   host1#flash-disk compare configuration

   The flash-disk compare configuration command, which validates only configuration files, excludes larger files such as software releases and scripts from the validation process. As a result, this command takes less time to complete than the flash-disk compare all command, which validates all NVS files.

3. Review the flash-disk compare output to determine whether any files failed the checksum validation.

   If the flash-disk compare command detects differences in the content of one or more files, the router reports a checksum test failure.

4. If one or more files failed the checksum validation, determine whether the corrupted files reside on the primary SRP module or on the redundant SRP module.
5. If the corrupted file resides on the primary SRP module, issue the srp switch command to force a switch from the primary SRP module to the redundant SRP module.

   This action ensures that the error-free version of the file will be on the SRP module that takes control after the switch.

6. Issue the synchronize command with the low-level-check keyword to force the router to:
   • Validate all files in NVS (when you use the all keyword) or only configuration files in NVS (when you use the configuration keyword).
   • Synchronize all files that failed the checksum test during the flash-disk compare command, as well as any other unsynchronized files.

     host1#synchronize low-level-check all

     host1#synchronize low-level-check configuration

     This action resolves any file discrepancies between the primary and redundant SRP modules and restore SRP file integrity.

     Note: Both the flash-disk compare and synchronize low-level-check commands perform CPU-intensive processing that can take several minutes to complete. For best results, do not run these commands simultaneously on the same router. In addition, do not run multiple instances of the flash-disk-compare command simultaneously on the same router.

flash-disk compare

• Use to perform a checksum validation that compares the contents of the NVS file system on the primary SRP module with the contents of the NVS file system on the redundant SRP module.
• The command validates only those files that are synchronized between the primary and redundant SRP modules; it does not validate log files, core dump files, and other files that are excluded from the system synchronization process.
• Specify one of the following keywords:
  • all—Compares all files in NVS; this option can take several minutes to complete.
  • configuration—Compares only configuration files; this option takes less time to complete because it compares only a subset of the files in the NVS file system.
• If all files pass the validation test, the router reports that all checksums matched and displays the total number of files and total number of bytes of information compared.
• If one or more files fail the validation test, the router reports a checksum test failure and does not display the total number of files and bytes compared.
• If one or more of the following conditions exist, the command fails and the router displays a message that explains why it cannot perform the checksum test:
  • The file systems on the primary flash card and the redundant flash card are not synchronized.
  • The router does not contain a redundant SRP module.
  • The redundant SRP module is offline.
• Example 1—Shows output when all files passed the validation test

  host1#flash-disk compare all
  WARNING: This command may take several minutes to complete.
  Proceed? [confirm]
  WARNING: No changes should be made to the system while this command is in
           progress.
  Please wait.........................................................
  All file checksums matched.
  Number of Files = 866
  Number of Bytes = 61660650

• Example 2—Shows output when one or more configuration files failed the validation test

  host1#flash-disk compare configuration
  WARNING: This command may take several minutes to complete.
  Proceed? [confirm]
  WARNING: No changes should be made to the system while this command is in
           progress.
  Please wait......
  At least one configuration file failed checksum test.

• There is no no version.
• See flash-disk compare.

synchronize

• Use to force the NVS file system of the redundant SRP module to synchronize with the NVS file system of the primary SRP module.
• If you synchronize the redundant SRP module with the primary SRP module and the redundant module is armed with a release different from the one it is currently running, the redundant SRP module is automatically rebooted to load the armed release.
• Optionally, you can use the low-level-check keyword to force the router to validate all files or only configuration files in NVS, and to synchronize all files that failed the checksum validation test during the flash-disk-compare command as well as any other files that are unsynchronized.
• When you use the low-level-check keyword, you must also specify one of the following keywords:
  • all—Validates all files in NVS, and synchronizes all files that failed the checksum test as well as any other unsynchronized files; this option can take several minutes to complete.
  • configuration—Validates all configuration files in NVS, and synchronizes all files that failed the checksum test as well as any other unsynchronized files; this option takes less time to complete because it validates only a subset of the files in the NVS file system.
• If one or more of the following conditions exist when you use the low-level-check keyword, the command fails and the router displays a message that explains why it cannot perform the synchronization:
  • The router does not contain a redundant SRP module.
  • The redundant SRP module is offline.
  • The armed releases are different on the primary SRP and redundant SRP.
• Examples

  host1#synchronize

  host1#synchronize low-level-check all

  host1#synchronize low-level-check configuration

• There is no no version.
• See synchronize.

Copyright © 2008, Juniper Networks, Inc. All rights reserved. Trademark Notice.