Linux error in a server with kernel: st reservation conflict – tapes not available

In a Linux server it was not showing the tape drives available that were previously available.

On /var/log/messages was showing a message about a reservation conflict

Nov 29 00:49:15 linux kernel: st 3:0:19:0: reservation conflict

This message is about the SCSI reservation that the backup software is applying to the tape drives.

Once the software finishes using the tapes it will make them available to other servers