VMBTMP0557E Unable to allocate a volume through VMTAPE, error 24 from RESERVE TAPE command.

Products

• VM:Backup for z/VM
• VM:Backup High-Speed Disaster Recovery Option (HiDRO)
• Mainframe VM Product Manager
• VM:Manager Suite for Linux on Mainframe
• VM:Manager Suite for z/VM
• VM SUITE
• VM:Tape for z/VM

Issue/Introduction

Unable to allocate a volume through VMTAPE, error 24 from RESERVE TAPE command. 

Resolution

RESERVE OFF in the VMBACKUP CONFIG file is not causing the following error:
VMBTMP0557E Unable to allocate a volume through VMTAPE, error 24 from RESERVE TAPE command.

RESERVE in VM:Backup's configuration file is what controls whether or not VM:Tape will reserve the number of tape drives VM:Backup will need for the job, before it can even start. If the job is going to need 6 drives, the VM:Backup job will not start until there are 6 drives reserved for VM:Backup's use.

This is the command that VM:Backup issues to VM:Tape when asking for a SCRATCH tape whether or not RESERVE is ON or OFF;
VMTVMB600I Beginning: 'RESERVE TAPE SCRATCH 310 DSN VMBACKUP.PRIMARY (LABEL SL DEN EXF POOL SCRATCH' for 00000

If VM:Tape does not have any drives that match the criteria in the RESERVE TAPE command, this message appears on VM:Tape:
VMTMNP199E No devices match the given criteria
On the VM:Backup console then you will see:
VMBTMP0557E Unable to allocate a volume through VMTAPE, error 24 from RESERVE TAPE command.
Error 24 indicates that there is not a drive known to VM:Tape that matches the criteria sent on the VM:Backup RESERVE TAPE SCRATCH command which includes the DEN option from the TAPEPOOL record associated with the VM:Backup job.

With RESERVE ON, this is what would be seen in the console:
VMTVMB600I Beginning: 'RESERVE DRIVE (COUNT 1 NOQUEUE DEN
then - VMTVMB600I Beginning 'RESERVE TAPE SCRATCH 310 DSN VMBACKUP.PRIMARY (LABEL SL DEN EXF POOL SCRATCH' for 00000

Most often this is a case of the VM:Backup TAPEPOOL record not matching drives on VM:Tape. Another problem that can occur is either VM:Backup or VM:Tape did not get initialized with EDRSUP ON. Check to make sure that the VM:Backup TAPEPOOL record matches the MEDIA and DENSITY of the tapes in VM:Tape's setup. Also, if EDRSUP is ON in one of the products and not in the other, this needs to be corrected.