I have a very fast LTO4 Drive that I have write tested at about 5.5 gigabytes a minute. However when I backup local volumes to tape using Amanda, I am only getting a throughput of 500 to 700 megabytes a minute. My first inclination was to look to change block size in the GNU tar config. However, I have read that Amanda doesn't 'tar' directly to tape, so it's not tar's blocksize I need to change. Amanda does its writing to tape with a default blocksize of 32KiB. The amanda.conf man page list the blocksize int paremeter which can only be raised if AMANDA was compiled with the configure option --with-maxtapeblocksize=N set with "N" greater than 32 during configure. Does anybody know if the Amanda rpm that came with SLES 10SP1 was compliled with this option? Or is there another reason I am not able to use my LTO4 Drive to its full capablity. I understand there are file system limitations, but I have backed these files up at greater speeds to disk with much faster throughtput using cp.