At the Tuesday MDC-2 meeting, Pasha presented the way of doing full
rate test. 

1. Data goes from L3 to tape

2.           from tape to the production farm

3.           from the production farm to tape

My comment on this scheme is that this won't be a real full rate test due
to the interference of input and output on the IO node, the fcdfsgi1. The
interference is on tape drive, CPU usage, disk spinning. Networking should
not be an issue since input and output of fcdfsgi1 can go through
different Ethernet cards.

   With 8 AIT-2 tape drives, the throughput can go only up to 24 MB/s,
assuming 3 MB/s each. Clearly this is not enough for both in and out 
together. If we want to reach 20 MB/s throughput the IO node should be at
least capable of 40 MB/s.

   The interference is not tested in the current scheme!
 
   Can we (or Do we want to) get more tape drives?

   Best regards,    Yen-Chu Chen
                    chenyc@fnal.gov
                    Office: (630) 840-3225,  FAX: (630) 840-3867	
                    (886)-(2)-2789-9681 (Inst. of Phys., Academia Sinica)