Netbackup does not utilize a tape drive and fails with error "EMM staus: No drives are available"

Problem

Problem occurs when NetBackup fails to utilize the tape drive and tape drives show available in device monitor.

Error Message

NBU status: 800, EMM status: No drives are available

Cause

Run /usr/openv/volmgr/bin/tpconfig -emm_dev_list
For drive in question see Flags attribute:
Flags:                         1073741952
The drives flag was 1073741952 which in hexadecimal is 40000080
From LTItypes.h:
#define MM_RESTART_LTID 0x40000000 /* a device configuration change has occurred on the emm server, and this host's daemons should be restarted */

Solution

In order to resolve this issue clear the flag or restart ltid on all media servers sharing the tape drive if vmoprcmd does not clear the flag.

Perform following command to clear the flag :
vmoprcmd -reset_ltid_restarted_bit -h <host name>
Location :
Unix : /usr/openv/volmgr/bin/
Windows : Program Files\Veritas\Volmgr\bin