lp-Spool and many Printers whithout Problems ?

[Banas Lothar]

Hello,
We use HPUX 11.11 on the following engine:
RP7400 (or N4000) with two Processor and 16GB Memory
How many Printers allow the lp_daemon without produce an "hold on" of the engine?
We have around 2500 Printers in a Network to define. Is this possible?

Thank you for answer

[Rainer von Bongartz]

This should be no problem for the box .

But take care of a very larger spool area on your disk (/var/spool/lp) might fill up .
Of course it depends on what kind of jobs you are printing.

If you are building up this print server from scratch you should consider using CUPS which might scale better in your case than lp


Regards
rainer

[Bill Hassell · Accepted solution]

lp scales fairly well and with a high end processor, the queue depth of 2500 is not much of a problem while running as the load is quite small. HOWEVER, start/stop is a very different matter. If you have to shutdown the spooler (or the computer) and there are hundreds, perhaps thousands of jobs in progress, each job will be restarted when the spooler is started again. This will represent a fairly serious load on the system during the startup and of course, every active job starts from the beginning again.

The real problem is going to be changes to the spooler. EVERY printer add or delete will require stopping the spooler. This is a feature of SysV lp spooler. Now if printer changes can be scheduled for an overnight maintenance window, you should be OK.

And I would definitely create a separate mountpoint for /var/spool/lp/request. This directory could grow to several Gb in a short time due to user actions like printing a large file 10 times because the first one didn't 'go through'. Making /var large is not the best solution as there may be other competing subsystems using /var.

If the start/stop features of the SysV lp spooler aren't going to work well, look at 3rd party spooling solutions, specifically scaleability and ease of maintenance.

[Steve Steel]

Hi

Also do not forget that each printer access is via user lp so you must put maxuprc to at least 3 times the number of printers or it will not fork.

When machine is slow you can always do something like this

#!/bin/ksh
#
#Printer parameter
#
# parameter is enable disable accept or reject to do all printers
#
option=$1
xx=`lpstat -p|grep printer|cut -f2 -d" "`
for printer in $xx
do
case $option in
accept) accept $printer ;;
reject) reject $printer ;;
enable) enable $printer ;;
disable) disable $printer ;;
*)echo invalid parameter ;;
esac
sleep 2
done

Print requests are stored if you disable your printers so if you have problems disable the printers and when machine is ok enable again and printing will continue


Steve Steel

The truth is out there.But I Forgot the url.