Hopefully this will be useful to someone. ==================================================
Notes: - the name of the AMANDA server is 'blather' - You may (or may not) need to label the tape before running 'amtapetype' (I did the first time I used the tape). - Rebooting causes the drive to turn HW compression back on. I have not found a way to turn it off that survives rebooting. If anyone knows of one, please let me know :) - There is amtapetype output for this drive at the website: http://amanda.sourceforge.net/fom-serve/cache/453.html define tapetype SDLT600 { comment "just produced by tapetype prog (hardware compression off)" length 307200 mbytes filemark 0 kbytes speed 9160 kps } As you'll see below, I got the same tape size but a very different speed. # # Hardware compression turned on? # root blather:/usr/local/building/amanda/tape-src <Mon May 23 14:37> 1025 # ./amtapetype -o -c -f /dev/nst0 Writing 2048 Mbyte compresseable data: 37 sec Writing 2048 Mbyte uncompresseable data: 66 sec WARNING: Tape drive has hardware compression enabled Estimated time to write 2 * 1024 Mbyte: 66 sec = 0 h 1 min # # Yes -- double check with the drive # root blather:/usr/local/building/amanda/tape-src <Mon May 23 15:38> 1030 # mt -f /dev/nst0 datcompression Compression on. Compression capable. Decompression capable. # # turn hardware compression off # root blather:/usr/local/building/amanda/tape-src <Mon May 23 15:38> 1031 # mt -f /dev/nst0 datcompression off Compression off. Compression capable. Decompression capable. # # double check again # root blather:/usr/local/building/amanda/tape-src <Mon May 23 15:38> 1032 # mt -f /dev/nst0 datcompression Compression off. Compression capable. Decompression capable. # # double check again with 'amtapetype -c' # root blather:/usr/local/building/amanda/tape-src <Mon May 23 15:38> 1033 # ./amtapetype -o -c -f /dev/nst0 Writing 2048 Mbyte compresseable data: 60 sec Writing 2048 Mbyte uncompresseable data: 60 sec Estimated time to write 2 * 1024 Mbyte: 60 sec = 0 h 1 min # # now get the tape type (approx. 5.5 h actual run time) # root blather:/usr/local/building/amanda/tape-src <Mon May 23 15:56> 1037 # ./amtapetype -e 300g -t SDLT600 -f /dev/nst0 Writing 4096 Mbyte compresseable data: 124 sec Writing 4096 Mbyte uncompresseable data: 125 sec Estimated time to write 2 * 307200 Mbyte: 18750 sec = 5 h 12 min wrote 9830400 32Kb blocks in 100 files in 9564 seconds (short write) wrote 9830400 32Kb blocks in 200 files in 9508 seconds (short write) define tapetype SDLT600 { comment "just produced by tapetype prog (hardware compression off)" length 307200 mbytes filemark 0 kbytes speed 32988 kps } That's It! -- Steve Lane System, Network and Security Administrator Doudna Lab Biomolecular Structure and Mechanism Group UC Berkeley
