This chapter explains how to troubleshoot printing problems that might occur when you set up or maintain printing services.
This is a list of the step-by-step instructions in this chapter.
For information about printing and the LP print service, see Chapter 2, Managing Printing Services (Overview).
Sometimes after setting up a printer, you find that nothing prints. Or, you might get a little farther in the process: something prints, but it is not what you expect, the output is incorrect or illegible. Then, when you get past these problems, other problems might occur, such as:
LP commands hanging
Printers becoming idle
Users getting conflicting messages
Although many of the suggestions in this chapter are relevant to parallel printers, they are geared toward the more common serial printers.
When nothing prints, there are three general areas to check:
The printer hardware
The network
The LP print service
If you get a banner page, but nothing else, this is a special case of incorrect output. See Troubleshooting Incorrect Output.
The hardware is the first area to check. As obvious as it sounds, you should make sure that the printer is plugged in and turned on. In addition, you should refer to the manufacturer's documentation for information about hardware settings. Some computers use hardware switches that change the characteristics of a printer port.
The printer hardware includes the printer, the cable that connects it to the computer, and the ports into which the cable plugs at each end. As a general approach, you should work your way from the printer to the computer. Check the printer. Check where the cable connects to the printer. Check the cable. Check where the cable connects to the computer.
Problems are more common with remote print requests that are going from a print client to a print server. You should make sure that network access between the print server and print clients is enabled.
If the network is running the Network Information Service Plus (NIS+), see System Administration Guide: Naming and Directory Services (FNS and NIS+) for instructions to enable access between systems. If the network is not running the Network Information Service (NIS) or NIS+, before you set up print servers and print clients, include the Internet address and system name for each client system in the /etc/hosts file on the print server. Also, the IP address and system name for the print server must be included in the /etc/hosts file of each print client system.
For printing to work, the LP scheduler must be running on both the print server and print client. If it is not running, you need to start it using the /usr/lib/lp/lpsched command. If you have trouble starting the scheduler, see How to Restart the Print Scheduler.
In addition to the scheduler running, a printer must be enabled and accepting requests before it will produce any output. If the LP print service is not accepting requests for a printer, the submitted print requests are rejected. Usually, in that instance, the user receives a warning message after submitting a print request. If the LP print service is not enabled for a printer, print requests remain queued on the system until the printer is enabled.
In general, you should analyze a printing problem as follows:
Follow the path of the print request step-by-step.
Examine the status of the LP print service at each step.
Is the configuration correct?
Is the printer accepting requests?
Is the printer enabled to process requests?
If the request is hanging on transmission, set up lpr.debug in syslog.conf to display the flow.
If the request is hanging locally, examine the lpsched log (/var/lp/logs/lpsched).
If the request is hanging locally, have notification of the printer device errors (faults) mailed to you, and re-enable the printer.
The procedures found in Troubleshooting Printing Problems use this strategy to help you troubleshoot various problems with the LP print service.
If the printer and the print service software are not configured correctly, the printer might print, but it might provide output that is not what you expect.
If you used the wrong printer type when you set up the printer with the LP print service, inappropriate printer control characters can be sent to the printer. The results are unpredictable: nothing might print, the output might be illegible, or the output might be printed in the wrong character set or font.
If you specified an incorrect file content type, the banner page might print, but that is all. The file content types specified for a printer indicate the types of files the printer can print directly, without filtering. When a user sends a file to the printer, the file is sent directly to the printer without any attempt to filter it. The problem occurs if the printer cannot handle the file content type.
When setting up print clients, you increase the chance for a mistake because the file content types must be correct on both the print server and the print client. If you set up the print client as recommended with any as the file content type, files are sent directly to the print server and the print server determines the need for filtering. Therefore, the file content types have to be specified correctly only on the server.
You can specify a file content on the print client to off-load filtering from the server to the client, but the content type must be supported on the print server.
Many formatting problems can result when the default stty (standard terminal) settings do not match the settings required by the printer. The following sections describe what happens when some of the settings are incorrect.
When the baud setting of the computer does not match the baud setting of the printer, usually you get some output, but it does not look like the file you submitted for printing. Random characters are displayed, with an unusual mixture of special characters and undesirable spacing. The default for the LP print service is 9600 baud.
If a printer is connected by a parallel port, the baud setting is irrelevant.
Some printers use a parity bit to ensure that data received for printing has not been garbled during transmission. The parity bit setting for the computer and the printer must match. If they do not match, some characters either will not be printed at all, or will be replaced by other characters. In this case, the output looks approximately correct. The word spacing is all right and many letters are in their correct place. The LP print service does not set the parity bit by default.
If the file contains tabs, but the printer expects no tabs, the printed output might contain the complete contents of the file, but the text might be jammed against the right margin. Also, if the tab settings for the printer are incorrect, the text might not have a left margin, it might run together, it might be concentrated to a portion of the page, or it might be incorrectly double-spaced. The default is for tabs to be set every eight spaces.
If the output is double-spaced, but it should be single-spaced, either the tab settings for the printer are incorrect or the printer is adding a line feed after each return. The LP print service adds a return before each line feed, so the combination causes two line feeds.
If the print zigzags down the page, the stty option onlcr that sends a return before every line feed is not set. The stty=onlcr option is set by default, but you might have cleared it while trying to solve other printing problems.
If you type any of the LP commands (such as lpsystem, lpadmin, or lpstat) and nothing happens (no error message, status information, or prompt is displayed), chances are something is wrong with the LP scheduler. Such a problem can usually be resolved by stopping and restarting the LP scheduler. See How to Stop the Print Scheduler for instructions.
You might find a printer that is idle, even though it has print requests queued to it. A printer might seem idle when it should not be for one of the following reasons:
The current print request is being filtered.
The printer has a fault.
Networking problems might be interrupting the printing process.
Slow print filters run in the background to avoid tying up the printer. A print request that requires filtering will not print until it has been filtered.
When the LP print service detects a fault, printing resumes automatically, but not immediately. The LP print service waits about five minutes before trying again, and continues trying until a request is printed successfully. You can force a retry immediately by enabling the printer.
When printing files over a network, you might encounter the following types of problems:
Requests sent to print servers might back up in the client system (local) queue.
Requests sent to print servers might back up in the print server (remote) queue.
Print requests submitted to a print server might back up in the client system queue for the following reasons:
The print server is down.
The printer is disabled on the print server.
The network between the print client and print server is down.
Underlying network software was not set up properly.
While you are tracking the source of the problem, you should stop new requests from being added to the queue. See How to Accept or Reject Print Requests for a Printer for more information.
If print requests back up in the print server queue, the printer has probably been disabled. When a printer is accepting requests, but not processing them, the requests are queued to print. Unless there is a further problem, once the printer is enabled, the print requests in the queue should print.
A user might enter a print request and be notified that the client system has accepted it, then receive mail from the print server that the print request has been rejected. These conflicting messages might occur for the following reasons:
The print client might be accepting requests, while the print server is rejecting requests.
The definition of the printer on the print client might not match the definition of that printer on the print server. More specifically, the definitions of the print job components, like filters, character sets, print wheels, or forms are not the same on the client and server systems.
You should check that identical definitions of these job components are registered on both the print clients and print servers so that local users can access printers on the print servers.
This section contains step-by-step instructions that explain:
How to troubleshoot no output
How to troubleshoot incorrect output
How to unhang the LP commands
How to troubleshoot an idle (hung) printer
How to resolve conflicting status messages
This task includes the following troubleshooting procedures to try when you submit a print request to a printer and nothing prints:
Check the hardware (How to Check the Printer Hardware).
Check the network (How To Check the Printer Network Connections).
Check the LP print service basic functions (How to Check the Basic Functions of the LP Print Service).
Check printing from a Solaris print client to a Solaris print server (How to Check Printing From a Solaris Print Client to a Solaris Print Server).
Try the first three procedures in the order in which they are listed, before going to the print client/server section. However, if the banner page prints, but nothing else does, turn to the instructions under How to Troubleshoot Incorrect Output.
Check that the printer is plugged in and turned on.
Check that the cable is connected to the port on the printer and to the port on the system or server.
Make sure that the cable is the correct cable and that it is not defective.
Refer to the manufacturer`s documentation. If the printer is connected to a serial port, verify that the cable supports hardware flow control. A NULL modem adapter supports this. The following table shows the pin configuration for NULL modem cables.
Table 31–1 Pin Configuration for NULL Modem Cables
Host |
Printer |
|
---|---|---|
Mini-Din-8 |
25-Pin D-sub |
25-Pin D-sub |
- |
1 (FG) |
1(FG) |
3(TD) |
2(TD) |
3(RD) |
5(RD) |
3(RD) |
2(TD) |
6(RTS) |
4(RTS) |
5(CTS) |
2(CTS) |
5(CTS) |
4(RTS) |
4(SG) |
7(SG) |
7(SG) |
7(DCD) |
6(DSR), 8(DCD) |
20(DTR) |
1(DTR) |
20(DTR) |
6(DSR), 8(DCD) |
Check that any hardware switches for the ports are set properly.
See the printer documentation for the correct settings.
Check that the printer is operational.
Use the printer's self-test feature, if the printer has one. Check the printer documentation for information about printer self-testing.
Check that the baud settings for the computer and the printer are correct.
If the baud settings are not the same for both the computer and the printer, sometimes nothing will print, but more often you get incorrect output. For instructions, see How to Troubleshoot Incorrect Output.
Check that the network link between the print server and the print client is set up correctly.
print_client# ping print_server print_server is alive print_server# ping print_client print_client not available |
If the message says the system is alive, you know you can reach the system, so the network is all right. The message also tells you that either a name service or the local /etc/hosts file has translated the host (system) name you entered into an IP address; otherwise, you would need to enter the IP address.
If you get a not available message, try to answer the following questions: How is NIS or NIS+ set up at your site? Do you need to take additional steps so that print servers and print clients can communicate with one another? If your site is not running NIS or NIS+, have you entered the IP address for the print server in each print client's /etc/hosts file, and entered all print client IP addresses in the /etc/hosts file of the print server?
(On a SunOS 5.0–5.1 print server only) Check that the listen port monitor is configured correctly.
(On a SunOS 5.0–5.1 print server only) Check that the network listen services are registered with the port monitor on the print server.
This procedure uses the printer luna as an example of checking basic LP print service functions.
On the print server, make sure that the LP print service is running.
Check whether the LP scheduler is running.
# lpstat -r scheduler is running |
If the scheduler is not running, become superuser or lp, and start the scheduler.
# /usr/lib/lp/lpsched |
If you have trouble starting the scheduler, see How to Unhang the LP Print Service.
On both the print server and print client, make sure that the printer is accepting requests.
Check that the printer is accepting requests.
# lpstat -a mars accepting requests since Jul 12 14:23 2001 luna not accepting requests since Jul 12 14:23 2001 unknown reason |
This command verifies that the LP system is accepting requests for each printer configured for the system.
If the printer is not accepting requests, become superuser or lp, and allow the printer to accept print requests.
# accept luna |
The specified printer now accepts requests.
On both the print server and print client, make sure that the printer is enabled to print submitted print requests.
Check that the printer is enabled.
# lpstat -p luna printer luna disabled since Jul 12 14:25 2001. available. unknown reason |
This command displays information about printer status. You can omit the printer name to obtain information about all printers set up for the system. The following example shows a printer that is disabled.
If the printer is disabled, become superuser or lp, and enable the printer.
# enable luna printer "luna" now enabled. |
The specified printer is enabled to process print requests.
On the print server, make sure that the printer is connected to the correct serial port.
Check that the printer is connected to the correct serial port.
# lpstat -t scheduler is running system default destination: luna device for luna: /dev/term/a |
The message device for printer-name shows the port address. Is the cable connected to the port to which the LP print service says is connected? If the port is correct, skip to Step 5.
Become superuser or lp.
Change the file ownership of the device file that represents the port.
# chown lp device-filename |
This command assigns the special user lp as the owner of the device file. In this command, device-filename is the name of the device file.
Change the permissions on the printer port device file.
# chmod 600 device-filename |
This command allows only superuser or lp to access the printer port device file.
On both the print server and print client, make sure that the printer is configured properly.
Check that the printer is configured properly.
# lpstat -p luna -l printer luna is idle. enabled since Jul 12 14:24 2001. available Content types: postscript Printer types: PS |
The above example shows a PostScript printer that is configured properly, and that is available to process print requests. If the printer type and file content type are correct, skip to Step 6.
If the printer type or file content type is incorrect, try setting the print type to unknown and the content type to any on the print client.
# lpadmin -p printer-name -T printer-type -I file-content-type |
On the print server, make sure that the printer is not faulted.
Check that the printer is not waiting because of a printer fault.
# lpadmin -p printer-name -F continue |
This command instructs the LP print service to continue if it is waiting because of a fault.
Force an immediate retry by re-enabling the printer.
# enable printer-name |
(Optional) Instruct the LP print service to enable quick notification of printer faults.
# lpadmin -p printer-name -A 'write root' |
This command instructs the LP print service to set a default policy of writing root, sending the printer fault message to the terminal on which root is logged in, if the printer fails. This might help you get quick notification of faults as you try to fix the problem.
Make sure that the printer is not set up incorrectly as a login terminal.
It is easy to mistakenly set up a printer as a login terminal, so be sure to check this possibility even if you think it does not apply.
Look for the printer port entry in the ps -ef command output.
# ps -ef root 169 167 0 Apr 04 ? 0:08 /usr/lib/saf/listen tcp root 939 1 0 19:30:47 ? 0:02 /usr/lib/lpsched root 859 858 0 19:18:54 term/a 0:01 /bin/sh -c \ /etc/lp /interfaces/luna luna-294 rocket!smith “passwd\n## # |
In the output from this command, look for the printer port entry. In the above example, port /dev/term/a is set up incorrectly as a login terminal. You can tell by the "passwd\n## information at the end of the line. If the port is set correctly, skip the last steps in this procedure.
Cancel the print request(s).
# cancel request-id |
In this command, request-id is the request ID number for a print request to be canceled.
Set the printer port to be a nonlogin device.
# lpadmin -p printer-name -h |
Check the ps -ef command output to verify that the printer port is no longer a login device.
If you do not find the source of the printing problem in the basic LP print service functions, continue to one of the following procedures for the specific client/server case that applies.
Check the basic functions of the LP print service on the print server, if you have not done so already.
For instructions on checking basic functions, see How to Check the Basic Functions of the LP Print Service. Make sure that the printer works locally before trying to figure out why nothing prints when a request is made from a print client.
Check the basic functions of the LP print service on the print client, if you have not done so already.
On the print client, the printer has to be enabled and accepting requests before any request from the client will print.
For most of the following steps, you must be logged in as root or lp.
Verify that the print server is operating properly.
# lpstat -t luna scheduler is running system default destination: luna device for luna: /dev/term/a luna accepting requests since Jul 12 14:26 2001 printer luna now printing luna-314. enabled since Jul 12 14:26 2001. available. luna-129 root 488 Jul 12 14:32 # |
The above example shows a print server up and running.
If the print server is not operating properly, go back to step 1.
Log in as superuser or lp.
Make sure that the printer type is correct.
An incorrect printer type might cause incorrect output. For example, if you specify printer type PS and the pages print in reverse order, try printer type PSR. (These type names must be in uppercase.) Also, an incorrect printer type might cause missing text, illegible text, or text with the wrong font. To determine the printer type, examine the entries in the terminfo database. For information on the structure of the terminfo database, see Printer Type.
On the print server, display the printer's characteristics.
$ lpstat -p luna -l printer luna is idle. enabled since Thu Jul 12 15:02:32 ... Form mounted: Content types: postscript Printer types: PS Description: Connection: direct Interface: /usr/lib/lp/model/standard After fault: continue Users allowed: (all) Forms allowed: (none) Banner not required Character sets: Default pitch: Default page size: 80 wide 66 long Default port settings: $ |
Consult the printer manufacturer's documentation to determine the printer model.
If the printer type is not correct, change it with Solaris Print Manager's Modify Printer Properties window, or use the following lpadmin command.
# lpstat -p printer-name -T printer-type |
On the print client, the printer type should be unknown. On the print server, the printer type must match a terminfo entry that is defined to support the model of printer you have. If there is no terminfo entry for the type of printer you have, see How to Add a terminfo Entry for an Unsupported Printer.
If the banner page prints, but there is no output for the body of the document, check the file content types.
File content types specified for a printer indicate the types of files the printer can print directly without filtering. An incorrect file content type causes filtering to be bypassed when it might be needed.
Note the information on file content type that was supplied in the previous step by the lpstat command.
On the print client, the file content type should be any, unless you have good reason to specify one or more explicit content types. If a content is specified on the client, filtering is done on the print client, rather than the print server. In addition, content types on the client must match the content types specified on the print server, which in turn must reflect the capabilities of the printer.
Consult your printer manufacturer's documentation to determine which types of files the printer can print directly.
The names you use to refer to these types of files do not have to match the names used by the manufacturer. However, the names you use must agree with the names used by the filters known to the LP print service.
If the file content type is not correct, change it with Solaris Print Manager's Modify Printer Properties window, or the following lpadmin command.
# lpadmin -p printer-name -I file-content-type(s) |
Run this command on either the print client, or print server, or both, as needed. Try -I any on the print client, and -I "" on the print server. The latter specifies a null file content type list, which means an attempt should be made to filter all files, because the printer can directly print only files that exactly match its printer type.
This combination is a good first choice when files are not printing. If it works, you might want to try specifying explicit content types on the print server to reduce unnecessary filtering. For a local PostScript printer, you should use postscript, or postscript,simple, if the printer supports these types. Be aware that PS and PSR are not file content types; they are printer types.
If you omit -I, the file content list defaults to simple. If you use the -I option and want to specify file content types in addition to simple, simple must be included in the list.
When specifying multiple file content types, separate the names with commas. Or you can separate names with spaces and enclose the list in quotation marks. If you specify any as the file content type, no filtering will be done and only file types that can be printed directly by the printer should be sent to it.
Check that the print request does not bypass filtering needed to download fonts.
If a user submits a print request to a PostScript printer with the lp -T PS command, no filtering is done. Try submitting the request with the lp -T postscript command to force filtering, which might result in the downloading of non-resident fonts needed by the document.
Make sure that the stty settings for the printer port are correct.
Read the printer documentation to determine the correct stty settings for the printer port.
If a printer is connected to a parallel or USB port, the baud setting is irrelevant.
Examine the current settings by using the stty command.
# stty -a < /dev/term/a speed 9600 baud; rows = 0; columns = 0; ypixels = 0; xpixels = 0; eucw 1:0:0:0, scrw 1:0:0:0 intr = ^c; quit = ^|; erase = ^?; kill = ^u; eof = ^d; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^q; stop = ^s; susp = ^z; dsusp = ^y; rprnt = ^r; flush = ^o; werase = ^w; lnext = ^v; parenb -parodd cs7 -cstopb -hupcl cread -clocal -loblk -parext -ignbrk brkint -ignpar -parmrk -inpck istrip -inlcr -igncr icrnl -iuclc ixon -ixany -ixoff imaxbel isig icanon -xcase echo echoe echok -echonl -noflsh -tostop echoctl -echoprt echoke -defecho -flusho -pendin iexten opost -olcuc onlcr -ocrnl -onocr -onlret -ofill -ofdel tab3 # |
This command shows the current stty settings for the printer port.
The following table shows the default stty options used by the LP print service's standard printer interface program.
Table 31–2 Default stty Settings Used by the Standard Interface Program
Option |
Meaning |
---|---|
-9600 |
Set baud rate to 9600 |
-cs8 |
Set 8-bit bytes |
-cstopb |
Send one stop bit per byte |
-parity |
Do not generate parity |
-ixon |
Enable XON/XOFF (also known as START/STOP or DC1/DC3) |
-opost |
Do “output post-processing” using all the settings that follow in this table |
-olcuc |
Do not map lowercase to uppercase |
-onlcr |
Change line feed to carriage return/line feed |
-ocrnl |
Do not change carriage returns into line feeds |
-onocr |
Output carriage returns even at column 0 |
-n10 |
No delay after line feeds |
-cr0 |
No delay after carriage returns |
-tab0 |
No delay after tabs |
-bs0 |
No delay after backspaces |
-vt0 |
No delay after vertical tabs |
-ff0 |
No delay after form feeds |
Change the stty settings.
# lpadmin -p printer-name -o "stty= options" |
Use the following table to choose stty options to correct various problems affecting print output.
Table 31–3 stty Options to Correct Print Output Problems
stty Values |
Result |
Possible Problem From Incorrect Setting |
---|---|---|
110, 300, 600, 1200, 1800, 2400, 4800, 9600, 19200, 38400 |
Sets baud rate to the specified value (enter only one baud rate) |
Random characters and special characters might be printed and spacing might be inconsistent |
oddp evenp -parity |
Sets odd parity Sets even parity Sets no parity |
Missing or incorrect characters appear randomly |
-tabs |
Sets no tabs |
Text is jammed against right margin |
tabs |
Sets tabs every eight spaces |
Text has no left margin, is run together, or is jammed together |
-onlcr |
Sets no carriage return at the beginning of line(s) |
Incorrect double spacing |
onlcr |
Sets carriage return at beginning of line(s) |
The print zigzags down the page |
You can change more than one option setting by enclosing the list of options in single quotation marks and separating each option with spaces. For example, suppose the printer requires you to enable odd parity and set a 7-bit character size. You would type a command similar to that shown in the following example:
# lpadmin -p neptune -o "stty='parenb parodd cs7'" |
The stty option parenb enables parity checking/generation, parodd sets odd parity generation, and cs7 sets the character size to 7 bits.
Verify that the document prints correctly.
# lp -d printer-name filename |
Log in as superuser or lp.
Stop the LP print service.
# /etc/init.d/lp stop |
Restart the LP print service.
# /etc/init.d/lp start |
The LP print service should restart. If you are having trouble restarting the scheduler, see How to Restart the Print Scheduler.
This task includes a number of procedures to use when a printer appears idle but it should not be. It makes sense to try the procedures in order, but the order is not mandatory.
Display printer status information.
# lpstat -p printer-name |
The information displayed shows you whether the printer is idle or active, enabled or disabled, or available or not accepting print requests. If everything looks all right, continue with other procedures in this section. If you cannot run the lpstat command, see How to Unhang the LP Print Service.
If the printer is not available (not accepting requests), allow the printer to accept requests.
# accept printer-name |
The printer begins to accept requests into its print queue.
If the printer is disabled, re-enable it.
# enable printer-name |
This command re-enables the printer so that it will act on the requests in its queue.
Check for print filtering by using the lpstat -o command.
$ lpstat -o luna luna-10 fred 1261 Mar 12 17:34 being filtered luna-11 iggy 1261 Mar 12 17:36 on terra luna-12 jack 1261 Mar 12 17:39 on terra $ |
See if the first waiting request is being filtered. If the output looks like the above example, the file is being filtered; the printer is not hung, it just is taking a while to process the request.
Look for a message about a printer fault and try to correct the fault if there is one.
Depending on how printer fault alerts have been specified, messages might be sent to root by email or written to a terminal on which root is logged in.
Re-enable the printer.
# enable printer-name |
If a request was blocked by a printer fault, this command will force a retry. If this command does not work, continue with other procedures in this section.
On the print client, stop further queuing of print requests to the print server.
# reject printer-name |
On the print client, send an “are you there?” request to the print server.
print_client# ping print_server print_server is alive |
If you receive the message print_server not available, you might have a network problem.
After you fix the above problem, allow new print requests to be queued.
# accept printer-name |
If necessary, re-enable the printer.
# enable printer-name |
On the print server, stop further queuing of print requests from any print client to the print server.
# reject printer-name |
Display the lpsched log file.
# more /var/lp/logs/lpsched |
The information displayed might help you pinpoint what is preventing the print requests from the print client to the print server from being printed.
After you fix the problem, allow new print requests to be queued.
# accept printer-name |
If necessary, re-enable the printer on the print server.
# enable printer-name |
On the print server, verify the printer is enabled and is accepting requests.
# lpstat -p printer-name |
Users will see conflicting status messages when the print client is accepting requests, but the print server is rejecting requests.
On the print server, check that the definition of the printer on the print client matches the definition of the printer on the print server.
# lpstat -p -l printer-name |
Look at the definitions of the print job components, like print filters, character sets, print wheels, and forms, to be sure they are the same on both the client and server systems so that local users can access printers on print server systems.