> I think it's because I am ignoring the NT machine that "owns" the
> JetDirect printer.  Here's the deal.  All my machines remote print to
> the queue on my Linux server.  On the server, that queue is tied
> to a JetDirect printer at a network address 192.168.109.40 or some
> such.  If a student prints to lp, it goes to the server and to the
> HP-4000 on the network.  Today we tried 25 students all printing
> a three page document at the exact same instant.  Each time
> we tried this, the first few came out and then the error message
> came that the printer lp was down.  I checked lpq on the server
> and the jobs were all there, but sure enough it reported the printer
> was down.  Plenty of paper, just no output.

Hm.  So you've designated one of the Linux systems to be the print 
spooler for the JetDirect, right?  Or are all of the workstations 
printing to the JetDirect's IP address?

If you are using one of the Linux systems as the spooler, then it 
alone should be in charge of sending lpr/lpd jobs to the JetDirect.  I 
have used plenty of JetDirect cards in this manner and it seems to work 
fine, because the print jobs accumulate on the Linux box and are sent 
one-at-a-time to the JetDirect.

> I was thinking that the printer, though on the network, still was
> owned by somebody.  There must be a queue manager for it
> somewhere.

I don't believe this is the case.  The JetAdmin software, which HP STILL 
wants you to use their DLC protocol for (although at least now you can also 
use TCP/IP), doesn't instill ownership of a JetDirect to anyone.  The 
JetDirect manages its own queue, although it has very little RAM and no 
hard disk.

It's optimal to have a PC running Linux, NT, or whatever to handle all 
print spooling and then only that PC sends print jobs to the JetDirect.  
One-job-at-a-time of course.

The JetDirect, because of its limited resources, will fill up its buffer 
fairly soon under load.  The only way it can tell the Linux system to 
stop sending data is probably to say "printer is down" or something like 
that.

>  I'm thinking that I'm not playing fair by sending my
> jobs directly to the printer -- shouldn't I be sending the to
> the machine that think's it's the machine controlling the printer?
> I wonder if that's why it goes down.  Yet I *really* don't want
> to send it to the NT machine to get to the printer.

I would bet that your NT machine doesn't think it's controlling the 
printer any more than the Linux machine, regardless of how it looks in 
the Printers control panel.

Actually using the NT machine as the print spooler for the printer would 
work fine, as long as the NT machine has a static IP address.  Make sure 
you install the "Microsoft TCP/IP printing" network software/service, and 
then re-apply your service pack to make sure all system files are the 
same revision.

Also, it helps if you name the printer something with no spaces in it; 
the Windows environment sometimes lets installer software name printers
"HP LaserJet 4000 TN printer with lots of options etc." whereas it's
easier to work with if its name were HP4000TN.  The "remote printer name"
in the Linux printer setup would then be "HP4000TN" or whatever you call
it on the NT side.  I've had trouble with getting unix printing to work if
the Windows NT printer name has spaces in it or is too long. 

Make sure the "Microsoft TCP/IP Printing" service (in the Control Panel |
Services) is set to start up automatically.  Windows NT and Windows 2000
include the TCP/IP printing service as an option [most admins do NOT
install it, unfortunately] whereas Windows 9x do not even have it as an
option.  Incidentally you get a LPR.EXE and other such tools included when
you install the TCP/IP Printing package.  I use it for debugging unix
print setups all the time - works great. 

> If I had an extra printer, I could put that on the Linux 
> server and print on the dedicated printer.  I gues I'll try that
> tomorrow.  But it would be nice to understand and fix the
> problem with sending to the JetDirect.  It's so much faster,
> and students like to send their print jobs when there is about
> 30 seconds left until the bell to change classes...

You will need a \I386 directory with the Windows NT installer files (a CD
or whatever) to install network software that wasn't installed initially. 
You'll also need your service pack software to reapply it to Windows NT,
if you do this. 

--
Jim Ockers (ockers@ockers.net)                     Ask me about Linux!
Contact info: please see http://www.ockers.net/

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