Chapter 11. Reinitializing Coda Servers after a Disaster

Table of Contents
Obtaining Backup Dump Files
Reinitializing the Servers

As Coda is still an experimental system, the state of a Coda File System may sometimes get to the point where you will want to reinitialize all of the servers.

Note: This is a fairly drastic step and should be treated as a last resort. It will typically take an entire day or more to perform and the system will be unavailable during that time. You will not be able to reintegrate after a re-initialization.

This chapter explains the steps necessary to reinitialize your system and restore your data on "clean" servers. The basic steps are as follows:

  1. Obtain backup dump files for all of the volumes in the system.

  2. Reinitialize RVM on the servers.

  3. Recreate the volumes that existed before the re-initialization.

  4. Restore and mount the backup clones created in step 1.

  5. Mount the volumes created in step 3.

  6. Copy the data from the restored volumes to the newly created volumes.

  7. Unmount the new volumes and backup clones.

  8. Flush client caches.

  9. Test the system.

Obtaining Backup Dump Files

If the system is in a state that backups can be successfully run, we suggest running the script to capture the most recent state. You may, however, use the tapes from your last successful backup and skip this step. See Chapter 10 and backup(8) for more details on creating backups. You will need to create new dumplist files for the backups. If you include the volumes that you do not normally back up in the newly created dumplists, you will be able to restore those volumes rather than re-create their contents. See dumplist(5) for details on the format of these files. To create the dumplists, use the following steps:

  1. Use /vice/vol/VolumeList and /vice/vol/VRList to create a list of all of the volumes on the servers you want to reinitialize.

  2. Sort the volumes by size. Use the cfs lv command to get an estimate on the size that each volume will take. Remember that if a volume is replicated, each replica will need space on the tape.

  3. Divide the volumes into groups that will fit onto a single backup tape (at CMU this is about 4 GB)

  4. Run backup on the dumplist files.