Server: ADSM V2.1 on OS/390
Comm: TCP/IP 3.2; 16Mb T/R
Client: Primarily Netware 4.10

A Netware client can backup its own local drives and can also backup a remote
drive on another Netware machine; i.e.  NetwareA can attach NetwareB's drives
as if they belonged to NetwareA.  We use this method when we don't want to
"pollute a Netware server with another destabilizing process" (not a decision
that I always agree with).  I've run benchmarks using a local drive and a
remote drive with a "LOAD DSMC SEL ..." of the same 15MB file on each drive.
As expected, the local drive backups are quicker: an average elapsed time of
34.9 seconds compared to 44.3 seconds on a remote drive.  But the network
throughput for a remote drive is much better than for the local drive: 1100
KB/S for the remote and only 640 KB/S for the local.

My guess is that the with the local drive, the token is released after every
TCP/IP block is sent upstream and ADSM must wait for it to make the rounds
before it can send another block.  But with remote drive access, the ADSM
station already has the token at the completion of the remote file I/O and
takes advantage of the possession by sending the TCP/IP block up immediately
(if one is ready).  Can anybody confirm/deny this or provide any other
explanation for the difference in throughput?

Thanks.
Alan Winsor
Blue Cross Blue Shield of RI
winsor.a AT bcbsri.e-mail DOT com