NOVELL TECHNICAL INFORMATION DOCUMENT
TITLE: CRONNLM4.EXE; CRON.NLM Server Utility v1.05
README FOR: CRONNLM4.EXE
NOVELL PRODUCTS and VERSIONS:
NetWare 3.12
NetWare 4.11
NetWare 4.1
IntranetWare
ABSTRACT:
CRON.NLM version 1.05(NetWare v3.12, v4.x, and IntraNetWare)
Cron schedules commands to be executed on a NetWare server at
specified dates and times.
NOTE: This utility helps system administrators. It is provided
free of charge as a courtesy, and therefore, is not a Novell
supported product. Problems or questions regarding this product
can be reported via e-mail to NTSUTIL@NOVELL.COM.
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DISCLAIMER
THE ORIGIN OF THIS INFORMATION MAY BE INTERNAL OR EXTERNAL TO
NOVELL. NOVELL MAKES ALL REASONABLE EFFORTS TO VERIFY THIS
INFORMATION. HOWEVER, THE INFORMATION PROVIDED IN THIS DOCUMENT
IS FOR YOUR INFORMATION ONLY. NOVELL MAKES NO EXPLICIT OR IMPLIED
CLAIMS TO THE VALIDITY OF THIS INFORMATION.
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ISSUE:
CRON.NLM
version 1.05(NetWare v3.12, v4.x, and IntraNetWare)
Copyright (C) 1997 Novell, Inc.
All Rights Reserved
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CONTENTS
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I. Abstract
II. Installation Instructions
III. Usage
IV. Product Description
V. Enhancements/Bug Fixes
VI. Known Issues
VII. Frequently Asked Questions
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I. ABSTRACT
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Cron schedules commands to be executed on a NetWare server at
specified dates and times.
NOTE: This utility helps system administrators. It is provided
free of charge as a courtesy, and therefore, is not a Novell
supported product. Problems or questions regarding this product
can be reported via e-mail to NTSUTIL@NOVELL.COM.
NOTE: For more advanced scheduling capabilities on a NetWare
server you can purchase third-party scheduling utilities.
For more information refer to the following web pages:
http://www.avanti-tech.com/taskmstr/tm_main.html.
http://www.classic.com
Novell does not support nor endorse these utilties.
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II. INSTALLATION INSTRUCTIONS
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Copy CRON.NLM to the SYS:\SYSTEM directory on your server.
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III. USAGE
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load cron [logfile size]
Logfile size specifies the size the logfile will reach before
restarting. This keeps the logfile from getting too large and
crashing the SYS volume. The default is 5 MB (5000000).
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IV. PRODUCT DESCRIPTION
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CRON.NLM is adapted from the well-known Unix clock daemon. Cron
runs all day, spending most of its time asleep. Once a minute it
wakes up and reads SYS:\ETC\CRONTAB. Any commands scheduled in
CRONTAB matching the current date and time are executed.
Cron records all actions in the log file SYS:\ETC\CRONLOG.
CRONTAB SYNTAX:
Each crontab entry has six fields, each separated by tabs or
spaces:
minute hour day-of-month month day-of-week command
Each entry is checked in turn, and any entry matching the current
time is executed. The entry * matches anything. A pound sign
(#) is a comment. Valid values are:
minute(0-59)
hour(0-23)
day-of-month(1-31)
month(0-11)
day-of-week(0-6) Note: week starts with 0=Sunday
Examples:
#Min Hr Dat Mo Day Command
#print time every minute
* * * * * time
#print volumes on the hour
0 * * * * volumes
#do backup Mon-Fri at 0430
30 4 * * 1-5 load sbackup
#Start Oracle database every morning at 7:00 a.m.
#Stop Oracle database every Sunday at 7:45 p.m.
0 7 * * * orastart
45 19 * * 0 orastop
#Mon, Wed, Fri at 1930 down server
30 19 * * 1,3,5 down
#Xmas morning at 0900 only
0 9 25 11 * load sing
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V. ENHANCEMENTS/BUG FIXES
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Enhancements to version 1.1:
- Enhanced to removed the 2K size limit for CRONTAB.
Enhancements to version 1.3:
- Enhanced checking of scheduling parameters in CRONTAB.
- Enhanced to execute commands on the minute mark.
- Enhanced to spawn NLMs rather than feeding them to the
keyboard buffer. All other commands are still fed to
the keyboard buffer.
- Fixed shutdown routine so that CRON can unload itself.
Bug Fixes to version 1.5:
- Whitespace before command were not being removed.
- When "Load <NLM>" is specified, the arguments were not being parsed
correctly.
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VI. KNOWN ISSUES
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Issue 1 - This version of Cron, schedules a wakeup call every 60 seconds
since the last time checked or the last command executed. It
does NOT attempt to reschedule itself exactly on the minute mark.
Issue 2 - The keyboard buffer is stuffed with the command so anyone typing
on the console at the time will have their keystrokes interrupted.
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VII. FREQUENTLY ASKED QUESTIONS
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Q: Can I run DOS commands or DOS batch files?
A: Cron can execute any command that is currently available from the
NetWare server such as loading NLMs or server console commands. It does
not provide DOS shell-like functionality.
Q: Some NLMs stay loaded even when they have completed. The next
time Cron tries to load it, it will give a "non-re-entrant"
error. How can I unload them?
A: Some NLMs have command-line options for auto-unloading. If
not, you can schedule an unload command one minute before the
load command. For example, if you want XYZBACK.NLM to run EVERY
night at 3:00 am, you would use "0 3 * * * load xyzback" in
CRONTAB. Unfortunately, xyzback requires a manual shutdown. It
ran fine early Friday morning, but because the administrator
didn't unload xyzback, the server could not load it fresh again
early Saturday and Sunday mornings. A new command needs to go in
CRONTAB: "59 2 * * * unload xyzback".
Q: Can I redirect NLM output to keep status reports?
A: Although you get a status report of cron in CRONLOG, you can
NOT get output from any NLM that cron schedules.
Self-Extracting File Name: cronnlm4.exe
Files Included Size Date Time
..\
CRONNLM4.TXT (This file)
CRON.NLM 6405 12-10-97 3:38:46 pm
Installation Instructions:
See Issues Section
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