Tape library media changer demo on Linux. we demonstrate with an older IBM enterprise tape library the IBM 3490E and Quantum LTO tape library i3 scaler.
The IBM 3490E tape library is a 10 slot autoloader that is a rebadged overland L490E and can support both 3480 18 track tape and 36 track 3490 and 3490E tape with compression. The tape drive is connected with single-ended SCSI. The drive can support both differential and single-ended SCSI with a simple internal adjustment.
The second tape library media changer is the newer LTO Quantum i3 Scalar tape library which uses a SAS interface. The library is equipped with two LTO tape drives and 100 slots, though only 50 are activated.
In the demonstration, we show how to identify the device names in Linux using
Dmesg |grep scsi
And then use mtx command to load and unload tape and query the inventory of the tape libraries. Once the tapes are loaded we use tar to read and write data and mt to check the status of the drives.
The mtx commands are — note: replace sg2 with the device name identified from dmesg
mtx -f /dev/sg2 status --- reports back slot status.
mtx -f /dev/sg2 unload 10 -- unloads drive 0 to slot 10
The tar commands are
tar -cvf /dev/st0 *.txt -- create a tar archive on tape device 0 of all txt files
tar -tvf /dev/sto – list files on the tape
tar -xvf /dev/st0 – restore files back from tape to the current directory