Backing up

Use one of the following methods to back up your database.

Optionally, you can back up from a replicated file system with one of the two Informix® backup options. However, the Informix data format and the secondary database server cannot be used together.

For more information about the ccmdb backup command, see:

Backup from a replicated file system location

During the backup process, copying and archiving the file system data cause database downtime. However, to reduce database downtime, the -synced_files option replicates the file system data to a different location and performs the backup from that location. However, this method requires additional disk space.

When using the ccmdb backup –synced_files db copy path option, the following actions occur, in this order:
  1. The file system data is copied to a different location. During this time, the database is available and not locked.
  2. The database is protected from user modification.
  3. The metadata is backed up.
  4. The file system data is copied again to pick up any changes. This operation is quick since it copies only the changes that were made to the database since the first copy was done.
  5. The database is unprotected so that users can work again.
  6. The backup is taken from the file system copy.

This option reduces the time the database is protected by moving most of the time to back up the file system data outside of the transaction.

The initial copy is slow, but for most of that time, the database is still available.
  • If the second location is already populated, the system compares the directory trees and copies only what has changed.
  • For faster operation, you can reuse the database copy directory after the first time you perform the backup.

Backup with new data format (Informix only)

The ccmdb backup -format platform_dependent … option is a faster method of dumping metadata from Informix. However, the resulting backup file is less portable.

This method can be restored only to the same OS platform and Rational® Synergy version.

This method is only for use with backup. Do not use for upgrading or switching platforms.

Backup from the secondary database server (Informix only)

This backup method uses the Informix RSS technology to keep a secondary database server in sync. The system performs the database integrity check and backup on the secondary server, leaving the primary server available for use. The second physical server must be configured like the primary.

To back up from the secondary database server:
  1. Create the secondary server (one time only).
  2. On the secondary server, run the ccmdb backup command.

    There is no specific command-line option for using the secondary server. The ccmdb backup command automatically chooses the secondary server when the command is running on the secondary server machine.

When you run the ccmdb backup command from the secondary server, the following actions occur, in this order:
  1. The database is protected.
  2. Informix does a catch-up sync to update the secondary server.
  3. The primary and secondary server synchronization is stopped.
  4. The database is unprotected so users can work again.
  5. The system performs the integrity check and backup on the secondary server.

This backup method is combined with the replicated file system backup method for least downtime.


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