I have ongoing issues with my Xerox Phaser 2550 printer under Centos 7. It always worked without any issues on Centos 6 before I upgraded to Centos 7.
The problem manifests itself by regularly (but not every time) printing page after page of garbage instead of the document that I wanted to print out. Sometimes it works, sometimes it doesn't. The same document might print fine now but then I get pages of garbage the next time I print.
I have it set up as a shared printer on my network; the other computers on my network are all Centos 6.
Printing from another computer on my network sometimes works but more often prints pages of garbage. When experimenting with this last night printing test pages from system-config-printer on a Centos 6 machine to the printer on this Centos 7 machine, I sometimes got a "Connecting to printer" message and then nothing printed until I restarted cups on the Centos 6 computer. This didn't happen every time; once again sometimes I got a test page printed, sometimes I got pages of garbage, sometimes I got the "connecting to printer" message and had to restart cups on the Centos 6 computer.
Having become tired of this, I disconnected the printer from my Centos 7 machine and connected it to one of the Centos 6 machines and it worked without error when printing from that computer directly and when printing to it from another Centos 6 machine.
The printer also showed up by magic as a discovered printer on the other Centos 6 machine, but didn't show up on the Centos 7 machine until I loaded system-config-printer on Centos 7, "new", and told it to search for network printers on the Centos 6 machine.
Therefore, automatic printer discovery doesn't seem to work on this Centos 7 machine either.
Now that the printer is connected to a Centos 6 machine again it appears to work fine when talking to other Centos 6 machines on the network and the printer is automatically discovered.
After searching for the network printer from the Centos 7 machine and setting it up using the default (just hitting ok after it found the printer), my first attempt at printing a test page gave me a sheet that says this:
#PDF-BANNER Template default-testpage.pdf Show printer-name printer-info printer-location printer-make-and-model printer-d river-name printer-driver-version paper-size imageable-area job-id options time- at-creation time-at-processing
This obviously wasn't what I expected to see, so I ran system-config-printer on the Centos 7 machine again and changed the printer driver for that printer to Xerox Phaser 3150, the same as the setting on the Centos 6 machine that the printer is now connected to.
Now the test page prints fine, but I get two sheets out of the printer every time I print the test page. The first one says "**** Warning: glyf overlaps cmap, truncating." Then the test page prints as expected.
After printing the test page I get a printer error icon (printer with a red dot and white line on it) in the notification area on my panel. Clicking on that icon does nothing and hovering over it does nothing either but the only way it goes away is if I log out and log back in.
In conclusion, the printing really doesn't work properly from this Centos 7 machine, regardless of whether the printer is directly connected or if I'm printing over the network. Direct connecting the printer causes it to print pages of garbage some of the time, automatic remote printer discovery doesn't work, and manually setting up up to print to the remote printer still generates an error of some kind but does appear to print.
I can find nothing in /var/log/cups that tells me anything useful. /var/log/cups/error_log isn't updated when I print to the remote printer, even though the printer error icon shows up on my panel. page_log just tells me that it printed a page.
All of this stuff works perfectly and automatically from Centos 6 (both printing to the local printer on a Centos 6 machine and printing over the network from a Centos 6 machine to another Centos 6 machine).