Table of Contents
This chapter provides information about updating from SLES 8 to SUSE LINUX Enterprise Server 9. Additionally, it provides general information about operating printers and helps find suitable solutions for operating printers in networks.
In the previous version, SuSE Linux Enterprise Server 8™, the two print systems, LPRng and lpdfilter and CUPS, were supplied as equal alternatives. In SUSE LINUX Enterprise Server 9, the focus shifts towards CUPS. Additionally, an LPRng configuration can no longer be converted to a CUPS configuration automatically. For this reason, before updating from SuSE Linux Enterprise Server 8™ to SUSE LINUX Enterprise Server 9, decide whether a migration from LPRng and lpdfilter to CUPS should be performed under SuSE Linux Enterprise Server 8™.
CUPS is the print system of the future. Even if the lprng and lpdfilter packages continue to be supplied, the changeover to CUPS is recommended in SUSE LINUX Enterprise Server 9 because of the following advantages:
individual setting of the print parameters on user level
optimum support for PostScript printers
“browsing” in the network
web front-end (on user level and in relation to administration)
After SUSE LINUX Enterprise Server 9, the configuration of LPRng and lpdfilter will no longer be supported by YaST, but must be performed manually. For this reason, a check should be made under SUSE LINUX Enterprise Server 9 to see whether CUPS meets requirements and whether a changeover is possible.
When updating CUPS, a distinction should be made between the following cases:
The software packages are updated, but the existing configuration files are accepted without change. After the update, the queues and cupsd continue to behave as before. This also means that many new features in SUSE LINUX Enterprise Server 9 are not used and must be configured later if necessary.
The existing software packages and the existing configuration files are replaced by the new software packages and their default configuration files. All new features are immediately available, but the queues must be created from scratch. The new features are described in detail in the following articles:
CUPS and the LPRng and lpdfilter system are fundamentally different.
In the case of CUPS, the configuration data for the queues is stored in /etc/cups/printers.conf and /etc/cups/ppd/. /etc/printcap is created by cupsd only for the purpose of compatibility with printcap-based application programs.
CUPS uses the IPP protocol. LPRng uses the LPD protocol.
CUPS normally needs more computing performance for more powerful filtering and the web interface.
|LPD Functionality with CUPS|
CUPS supports fundamental LPD functionality, both on the recipient side by means of the cups-lpd and on the sender side by means of the lpd back-end. However, CUPS does not support full LPRng functionality. It is also possible to use filter scripts of LPD-based print systems as System V style interface scripts.
The parallel operation of a test system makes it possible to migrate to CUPS in a secure way. The existing LPD print server remains active. SUSE LINUX Enterprise Server 9 is installed with CUPS on an additional system.
This procedure only works well for network printers, because printers connected directly to the LPD print server must be connected directly to the CUPS test system for testing purposes. The queues for the network printers are set up on the CUPS test system. Many network printers (or their network interfaces) become overloaded if they receive data from several computers at the same time. For this reason, printouts for the network printers to test should be paused on the LPD print server while testing with the CUPS test system.
If the queues on the CUPS test system are created with YaST, the web front-end of CUPS or another graphical tool, log the settings made precisely to enable them to be set up on the productive system at a later point. However, if the queues on the CUPS test system are only created with lpadmin commands, it is enough to record the lpadmin commands in a script then run the script on the productive system.
For queues that have only been configured with YaST:
Migrate from LPRng and lpdfilter to CUPS under SuSE Linux Enterprise Server 8™.
Update from SuSE Linux Enterprise Server 8™ to SUSE LINUX Enterprise Server 9.
There is no automatic migration for non-YaST queues. You can switch from LPRng and lpdfilter to CUPS, but an existing configuration cannot be migrated.
In the case of SuSE Linux Enterprise Server 8™, the two print systems, CUPS and LPRng and lpdfilter, are always configured simultaneously with the YaST printer configuration. The printer configuration stores all configuration data and creates the configuration for the current print system or for the new print system if the print system has been changed. The YaST printer configuration differentiates strictly between queues that it has created itself and those created another way. The latter are not changed and cannot be changed, but just overwritten with a new configuration.
In the case of SUSE LINUX Enterprise Server 9, YaST and other configuration tool (e.g., the CUPS web front-end) are synchronized. There is no more “private” YaST configuration data. This change makes it impossible to offer configuration conversion in SUSE LINUX Enterprise Server 9.