Devon, just a few more questions:

So you *are* using jumbo frames?  I saw that it was enabled in ndd,
but you haven't mentioned it outright.

Also, what network switching equipment are you using for these tests?

Also, I'm curious, how is it that 4Gb/s LTO-3 drives can write
"faster" than 2 Gb/s with contrived data?  It seems like it shouldn't
make a difference, since the data stream is compressed at the drive.

thanks!

-- nick



We've been pretty happy with the T2000's.

The tape library is an IBM 3584, the tape drives are IBM's 4Gb FC LTO-3
drives, there's a dedicated 4Gb HBA for each drive, and everything is
connected to 4Gb McData switches.

We used to have IBM's 2Gb FC LTO-3 drives, and with those the peak
performance was around 165MB/s per drive.  These 4Gb drives peak at
around 265MB/s per drive, though with all 3 tape drives active, we see
throughput closer to 220MB/s per drive...I'm guessing we're bottlenecked
by the ports on our disk subsystem at the moment, but since performance
is more than acceptable we're not looking to tune this any further - at
least not until our LTO-4 drives are installed next month ;).

-devon
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