As I mentioned in another thread, make sure you have the latest drive
microcode.  That helped our shop a lot.  The levels we got from IBM
were:

3570B: D1I4_234
3570C: D1I5_324

Yes, it's easy to get them mixed up.  They aren't available anywhere
for download, as far as I know.  You have to order them from IBM.

You can determine the latest level from the Services... menu, or, under
AIX, with lscfg -vl rmt0.
  DEVICE            LOCATION          DESCRIPTION

  rmt0              20-60-00-0,0      IBM Magstar MP Tape Subsystem

        Manufacturer................IBM
        Machine Type and Model......03570B12
        Serial Number...............xxxxxxxxxxxx
        Device Specific.(FW)........4234
        Loadable Microcode Level....A0B00E21

Another weirdity:  note that the microcode level is the Device Specific
line, *not* the Loadable Microcode Level line. Go figure.  The 4 digits
in Device Specific correspond to the last 4 digits of the microcode
level.
--
      /
      /
  /  *  /  Alan Hamilton
 *     *   alanh AT primenet DOT com