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. ----------------------------------------------------------------- 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. ----------------------------------------------------------------- ISSUE: CRON.NLM version 1.05(NetWare v3.12, v4.x, and IntraNetWare) Copyright (C) 1997 Novell, Inc. All Rights Reserved ________________________________________ CONTENTS ________________________________________ I. Abstract II. Installation Instructions III. Usage IV. Product Description V. Enhancements/Bug Fixes VI. Known Issues VII. Frequently Asked Questions ________________________________________ I. ABSTRACT ________________________________________ 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. ________________________________________ II. INSTALLATION INSTRUCTIONS ________________________________________ Copy CRON.NLM to the SYS:\SYSTEM directory on your server. ________________________________________ III. USAGE ________________________________________ 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). ________________________________________ IV. PRODUCT DESCRIPTION ________________________________________ 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 ________________________________________ V. ENHANCEMENTS/BUG FIXES ________________________________________ 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 " is specified, the arguments were not being parsed correctly. ________________________________________ VI. KNOWN ISSUES ________________________________________ 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. ________________________________________ VII. FREQUENTLY ASKED QUESTIONS ________________________________________ 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 ----------------------------------------------------------------- Any trademarks referenced in this document are the property of their respective owners. Consult your product manuals for complete trademark information. -----------------------------------------------------------------