Installation and User's Guide

The journal engine service does not record changes in specific system files, such asthe registry, in the journal. Therefore, a journal-based backup will not back up thisfile. See the journal service configuration file, tsmjbbd.ini, in the client installationdirectory for excluded system files.You can use journal-based backup when backing up file systems with small ormoderate amounts of change activity between backup cycles. If you have many filechanges between backup cycles, you will have very large change journals. Manychanges to the journal-based backup file might pose memory and performanceproblems that can negate the benefits of journal-based backup. For example,creating, deleting, renaming, or moving very large directory trees can also negatethe benefit of using journal-based backup instead of normal incremental backup.Journal-based backup is not intended to be a complete replacement for traditionalincremental backup. You should supplement journal-based backup with a fullprogressive incremental backup on a regular basis. For example, performjournal-based backups on a daily basis, and full incremental backups on a weeklybasis.Journal-based backup has the following limitations:v Individual server attributes are not available during a journal-based backup.Certain policy settings such as copy frequency and copy mode might not beenforced.v Other operating-system specific behaviors might prevent objects from beingprocessed properly. Other software that changes the default behavior of the filesystem might prevent file system changes from being detected.v If the file system is very active when a journal-based backup is in progress, it ispossible that a small number of deleted files will not be expired.Note:1. Journal-based backup is supported on a Version 4.2 or higher Tivoli StorageManager server.2. Multiple journal-based backup sessions are possible.3. When using antivirus software, there are limitations to journal-based backup.4. A journal-based backup might not fall back to the traditional incrementalbackup if the policy domain of your node is changed on the server. Thisdepends on when the policy set within the domain was last updated and thedate of the last incremental backup. In this case, you must force a fulltraditional incremental backup to rebind the files to the new domain. Use thenojournal option with the incremental command to specify that you want toperform a traditional full incremental backup, instead of the defaultjournal-based backup.Related tasks“Configuring the journal engine service” on page 31Incremental-by-date backupFor a file system to be eligible for incremental-by-date backups, you must haveperformed at least one full incremental backup of that file system. Running anincremental backup of only a directory branch or individual file will not make thefile system eligible for incremental-by-date backups.Chapter 4. Backing up your data 115