Found 0 changer(s) usable by the ‘amandabackup’ user

The Zmanda Management Console is not able to find or detect any changer devices attached to the backup server

This article is for Amanda Enterprise (AE).

Issue Symptoms

Found 0 changer(s) usable by the ‘amandabackup’ user
Unable to use changer device ‘/dev/sg0’, because the ‘amandabackup’ user lacks read and/or write access.
Ignoring changer device ‘/dev/sg1’, because no drives found in ‘mtx status’ output for this changer device.
Unable to use changer device ‘/dev/sg2’, because the ‘amandabackup’ user lacks read and/or write access.
Ignoring changer device ‘/dev/sg3’, because no drives found in ‘mtx status’ output for this changer device.

Issue Description 

The Zmanda Management Console is not able to find or detect any changer devices attached to the backup server.

Resolution

The first thing to check is whether the OS for the backup server is correctly seeing the changer device. The best way to do this is to run the system command “lsscsi”. If this command is not already installed on your backup server, it can be quickly installed as a package of the same name.
Run lsscsi with the “-g” option and look for a “mediumx” device that fits the make and model of your changer device: 

lsscsi -g

Note the /dev/sg* device that is associated with your changer device. If the changer device is not seen in the output, see your changer documentation for getting the system to correctly see the device.

If the changer device is associated with the /dev/sg3 device name, for instance, ensure that the amandabackup user has the correct access to this device by checking the attributes of the /dev/sg3 device name and the groups that the amandabackup user belongs to:

ls -l /dev/sg3
id amandabackup  

Once the amandabackup user can correctly access the changer device and ZMC services have been restarted as needed, ZMC should now be able to correctly detect the changer device.