72 lines
3.2 KiB
Markdown
72 lines
3.2 KiB
Markdown
The following shell commands can be used for database backup and restore on a
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running *PostgreSQL* server in an LibreTime system.
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You can dump the entire database to a zipped file with the combination of the
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**pg\_dumpall** command and **gzip**. The **pg\_dumpall** command is executed
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as the user *postgres*, by using the **sudo** command and the **-u** switch. It
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is separated from the **gzip** command with the pipe symbol.
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```bash
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sudo -u postgres pg_dumpall | gzip -c > libretime-backup.gz
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```
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This command can be automated to run on a regular basis using the standard
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**cron** tool on your server.
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When restoring a production database on a cleanly installed LibreTime system, it
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may be necessary to drop the empty database that was created during the new
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installation, by using the **dropdb** command. Again, this command is executed
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with **sudo** as the user *postgres*:
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```bash
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sudo -u postgres dropdb airtime
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```
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This **dropdb** command above is necessary to avoid 'already exists' errors on
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table creation when overwriting an empty LibreTime database in the next step.
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These errors might prevent some data from being restored, such as user account
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data.
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To restore, first unzip the backup file with **gunzip**, then use the **psql**
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command as the *postgres* user:
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```bash
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gunzip libretime-backup.gz
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sudo -u postgres psql -f libretime-backup
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```
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You should now be able to log in to the LibreTime web interface in the usual way.
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For safety reasons, your regular database backups should be kept in a directory
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which is backed up by your storage backup tool of choice; for example, the
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*/srv/airtime/database\_backups* directory. This should ensure that a storage
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restore can be made along with a matching and complete version of the LibreTime
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database from the day that the storage backup was made.
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Storage backup
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--------------
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Backing up the LibreTime database with **pg\_dumpall** will not back up the
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LibreTime media storage server, which is likely to need a great deal more backup
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space. Creating a compressed file from hundreds of gigabytes of storage server
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contents is likely to take a very long time, and may have little benefit for the
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amount of CPU power used, if the media files are already stored in a highly
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compressed format. It is also impractical to copy very large backup files across
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the network on a daily basis.
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Instead, it is preferable to use an incremental backup technique to synchronize
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the production LibreTime server storage with a backup server each day or night. If
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the backup server also contains an LibreTime installation, it should be possible
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to switch playout to this second machine relatively quickly, in case of a
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hardware failure or other emergency on the production server.
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A standard incremental backup tool on GNU/Linux servers is *rsync*
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[(http://rsync.samba.org/)](http://rsync.samba.org/)) which can be installed
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using the package manager of your GNU/Linux distribution. However, incremental
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backup alone cannot help in the scenario where a file which later proves to be
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important has been deleted by an administrator. For backups that can be rolled
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back to restore from an earlier date than the current backup, the tool
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*rdiff-backup*
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[(http://www.nongnu.org/rdiff-backup/](http://www.nongnu.org/rdiff-backup/)) can
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be deployed.
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