mythtv-setup is a configuration utility for Mythbackend. Below you will see my standard configuration of Mythbackend.
See: Video Capture Card
Video Sources define the methods for retrieving EPG listing data into the system. These sources can be created using Mythtv-Setup and then associated with specific Capture Cards in the Input Connections screen. Section 9.1 of the manual describes the setup process for video sources. North American users can choose DataDirect to supply the schedule information while those outside North America should use XMLTV. Transmitted guide data (EIT) can also be used as a source or a supplement to the other sources if it is available.
This information is stored in the database as entries in the videosource table.
Associate video sources with capture cards.
Storage Groups are lists of directories that are used to hold MythTV recording files. By default, there is only one Storage Group, called "Default". You may create additional Storage Groups to store specific recordings in their own directories. Storage Groups are editted via the 'Storage Directories' section of Mythtv-Setup. You may want to add multiple directories (which are mounted on different hard drives) to a Storage Group in order to spread out filesystem I/O onto multiple filesystems.
You can also create multiple Storage Groups to group recordings together; recording schedules now have an option to specify which Storage Group to use.
MythTV will balance concurrent recordings across the available directories in a Storage Group in order to spread out the file I/O load. MythTV will prefer filesystems that are local to the backend, over filesystems that are remote until the local filesystem has 2 concurrent recordings active or other equivalent I/O, then the next recording will go to the remote filesystem. The balancing method is based purely on I/O, Myth does not try to balance out disk space unless a filesystem is too low on free disk space in which case it will not be used except as a last resort.
Storage Groups are global, but can be overridden on a slave backend by creating a local Storage Group by running mythtv-setup on the slave. If a problem occurs and the slave backend is unable to use the desired Storage Group, it will fail back and try the directories defined in the master's Storage Group.
You can also create a special 'LiveTV' Storage Group. If a LiveTV Storage Group directory exists, it will be used instead of putting LiveTV recordings in the Default Storage Group, allowing you to put your LiveTV recordings on their own filesystem. This is similar to the old MythTV method which used a RingBuffer for LiveTV.
Usage information for all Storage Group directories is visible on the mythfrontend status screen as well as the mythbackend status webpage. MythTV is smart enough to determine which directories are on shared filesystems so it should not count free or used space multiple times if you have more than one directory on the same filesystem.