would give you roughly 18,000MB/hour, so you're getting roughly ideal performance in writing 13-15GB uncompressed in ~90 minutes
I've moved this from the LINUX forum to here because 1) no one answered and 2) it may well be a PC hardware issue.
The PC is a Dell Optiplex 745 running SUSE 10.1 LINUX with a DELL 120T DLT7000 autoloader connected via an Adaptec AHA2944UW SCSII PCI card (supports up to 40MB/second). Its a stock DELL except for the 2944 card and installing SUSE over XP.
The DLT drive is rated to 35GB uncompressed.
I normally backup around 13 - 15 GB per tape and never in compressed mode. The tar backup takes about 1 1/2 hours to complete. The verify read (directory file list only) take between 3 and 4 times as long to complete.
I am using new Fuji DLT Tape IV tapes.
I've tested this on several SUSE machines with similar interfaces and get roughly equivalent results as well as with other DLT 7000 drives.
This seems extremely slow write and read given the stated transfer rate for DLT 7000 series drives of 5MB/second sustained.
Am I missing something on tar -t -v? Or is this a hardware issue? Is this what I should expect in terms of performance?