It’s little things like this which improve the copying of backups to tape. Speed.
30-Mar 13:40 crey-sd JobId 167778: Ready to read from volume "IncrAuto-4150" on device "CreyFile" (/usr/local/bacula/volumes). 30-Mar 13:40 crey-sd JobId 167778: Forward spacing Volume "IncrAuto-4150" to file:block 0:2889467570. 30-Mar 13:41 crey-sd JobId 167778: End of Volume at file 1 on device "CreyFile" (/usr/local/bacula/volumes), Volume "IncrAuto-4150" 30-Mar 13:41 crey-sd JobId 167778: Ready to read from volume "IncrAuto-4151" on device "CreyFile" (/usr/local/bacula/volumes). 30-Mar 13:41 crey-sd JobId 167778: Forward spacing Volume "IncrAuto-4151" to file:block 0:214. 30-Mar 13:43 crey-sd JobId 167778: End of Volume at file 1 on device "CreyFile" (/usr/local/bacula/volumes), Volume "IncrAuto-4151" 30-Mar 13:43 crey-sd JobId 167778: Ready to read from volume "IncrAuto-4235" on device "CreyFile" (/usr/local/bacula/volumes). 30-Mar 13:43 crey-sd JobId 167778: Forward spacing Volume "IncrAuto-4235" to file:block 0:214. 30-Mar 13:46 crey-sd JobId 167778: End of Volume at file 1 on device "CreyFile" (/usr/local/bacula/volumes), Volume "IncrAuto-4235" 30-Mar 13:46 crey-sd JobId 167778: Ready to read from volume "IncrAuto-4152" on device "CreyFile" (/usr/local/bacula/volumes). 30-Mar 13:46 crey-sd JobId 167778: Forward spacing Volume "IncrAuto-4152" to file:block 0:214. 30-Mar 13:48 crey-sd JobId 167778: End of Volume at file 1 on device "CreyFile" (/usr/local/bacula/volumes), Volume "IncrAuto-4152" 30-Mar 13:48 crey-sd JobId 167778: Ready to read from volume "IncrAuto-1454" on device "CreyFile" (/usr/local/bacula/volumes). 30-Mar 13:48 crey-sd JobId 167778: Forward spacing Volume "IncrAuto-1454" to file:block 0:214. 30-Mar 13:50 crey-sd JobId 167778: End of Volume at file 1 on device "CreyFile" (/usr/local/bacula/volumes), Volume "IncrAuto-1454" 30-Mar 13:50 crey-sd JobId 167778: Ready to read from volume "IncrAuto-1455" on device "CreyFile" (/usr/local/bacula/volumes). 30-Mar 13:50 crey-sd JobId 167778: Forward spacing Volume "IncrAuto-1455" to file:block 0:214. 30-Mar 13:52 crey-sd JobId 167778: End of Volume at file 1 on device "CreyFile" (/usr/local/bacula/volumes), Volume "IncrAuto-1455" 30-Mar 13:52 crey-sd JobId 167778: Ready to read from volume "IncrAuto-1456" on device "CreyFile" (/usr/local/bacula/volumes). 30-Mar 13:52 crey-sd JobId 167778: Forward spacing Volume "IncrAuto-1456" to file:block 0:214.
Each of those Volumes are 5GB in size. The tape drive takes about about 2-4 minutes per 5GB to write it to tape.
Between the end of IncrAuto-4150 and the end of IncrAuto-1455, the tape drive wrote 20GB in about 9 minutes. That’s roughly 2GB/minute or about 37MB/s.