Linux tape drive throughput performance statistics
Solution 1:
tapestat, part of the iostat package.
[dan@lnaapp-backup ~]$ tapestat 1 1
Linux 3.10.0-514.el7.x86_64 (lnaapp-backup.internal.lr.org) 05/07/17 _x86_64_ (24 CPU)
Tape: r/s w/s kB_read/s kB_wrtn/s %Rd %Wr %Oa Rs/s Ot/s
st0 0 106 0 27284 0 11 21 0 0
st1 0 0 5 0 0 0 21 0 0
st2 0 0 5 0 0 0 11 0 0
st3 0 0 3 0 0 0 19 0 0
Solution 2:
Set up some test suite to get this information. Use dd with various data sizes and block sizes. Use data sources of /dev/zero, /dev/urandom (to allow for tape compression and to try to avoid tape compression). Create big files filled with /dev/zero and /dev/urandom. Copy production file systems and use dd to push the file system device to tape. Push a tar of a production file system to tape. Copy all files from a file system to tape. Copy database files to tape. Perform all these test with tape drives mounted and unmounted. Time each command or batch script.
Solution 3:
Test a representative set of backup data and time it. Run a tool like nmon during backup and monitor transfer speed live. Your tape drive's performance if going to depend heavily on your interconnect, disk speed, compression settings and the actual data set.
However, for HP tape devices, there's a Library and Tape Tools package that can perform tape drive throughput testing. I'm not certain if it works with non HP drives, but it's worth a try.