IBM Tivoli Storage Manager for UNIX and Linux: Backup-Archive ...

||||||||||||||To support journal-based backup you must install and configure the Tivoli StorageManager daemon. See “Configuring the journal daemon” on page 56 forinformation about installing and configuring the daemon.Notes:1. Journal-based backup is supported on a Version 4.2 or higher Tivoli StorageManager server.2. 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.Incremental-by-datebackupFor a file system to be eligible for incremental-by-date backups, you must have performedat least one full incremental backup of that file system. Running an incremental backup ofonly a directory branch or individual file will not make the file system eligible forincremental-by-date backups.The client backs up only those files whose modification date and time is later thanthe date and time of the last incremental backup of the file system on which thefile resides. Files added by the client after the last incremental backup, but with amodification date earlier than the last incremental backup, are not backed up.Files that were renamed after the last incremental backup, but otherwise remainunchanged, will not be backed up. Renaming a file does not change themodification date and time of the file. However, renaming a file does change themodification date of the directory in which it is located. In this case, the directoryis backed up, but not the files it contains.If you run an incremental-by-date backup of the whole file system, the serverupdates the date and time of the last incremental backup. If you perform anincremental-by-date backup on only part of a file system, the server does notupdate the date of the last full incremental backup. In this case, the nextincremental-by-date backup will back up these files again.Comparing full incremental, partial incremental, andincremental-by-dateIncremental-by-date, and journal-basedbackupsFull incremental, partial incremental, journal-based, and incremental-by-date allback up new and changed files. An incremental-by-date backup takes less time toprocess than a full incremental backup and requires less memory.|||||||The memory requirements for an initial journaling environment are the same asthe memory requirements for a full file space incremental, because journal-basedbackups must complete the full file space incremental in order to set the journaldatabase as valid, and to establish the baseline for journaling.The memory requirements for subsequent journal-based backups are much less.Journal backup sessions run in parallel and are governed by the resourceutilizationclient option in the same manner as normal backup sessions. The size of the90 IBM Tivoli Storage Manager for UNIX and Linux: Backup-Archive Clients Installation and User’s Guide