Ref: 16530005
Title: Tips for Preventing "Other Operation in Progress" Error
Date: 8/30/89

Copyright 3Com Corporation, 1991.  All rights reserved.

The "Other Operation in Progress" error is serious.  If it
appear, the server must be rebooted to resume operation.
Following are nine tips for preventing this error on servers with
tape backup service.

1.  Wait five minutes after booting the server before beginning to
back it up.

2.  Wait until the server has finished initializing before
putting a tape in the drive.

3.  In the CIOSYS data area, make sure there is 4 KB of space in
the CIOSYS data area so Backup will run properly.

4.  Make sure the threads are set correctly (10 for a 3S/40X and 7
for a 3S/20X).

5.  Set the number of receive buffers to be 80% of the number of
transmit buffers; for example, 24 receive buffers and 30 transmit
buffers.

6.  On a 3S/401, leave 64 KB of EMS for CIOSYS.  On a 3S/201,
leave 34K of EMS for CIOSYS.

7.  Make sure your message buffers are at least one greater than
the number of concurrent requests.  You may want to add a couple
more as the tape service is also sending read and write requests
to the server.

8.  Increase the number of concurrent requests allowable.
Concurrent requests specify the maximum number of File or Print
service operations the server can handle at one time.  Tape
backup and restore initiate file operations (either remote or
locally) and provisions should be made for their use.

9.  Increase the -h (hold back) parameter by 3-5.  The -h
parameter specifies the number of -b buffers to reserve for use
by services installed on the same server.  When services on the
same server need to communicate with each other (such as 3+route,
3+Mail, the name service, 3+NetConnect, and 3+Share) they use
hold-back buffers for their communications.  Also, the tape
service will make a call to the file service on the same
server to do a backup of that server.
