this message appear during booting(before linux start screen appears)
modprobe:can't locate module char-major-188

how do???

Interesting, this looks like a line I had to add into my scanner.c file to compile a module for my scanner. I'm sure this line probably has many uses that was the first I had seen it. Have you, by any chance, recently installed a scanner??

rberry88

char-major-188 is referring to your USB port(s). If you don't use USB you can ignore the error or put the following line in /etc/modules.conf to suppress the message:

alias char-major-188 off

If you do use USB, it sounds like a USB-related module isn't correctly.

Well I guess the learning never stops. I would never have guessed that had to do with USB ports, I was thinking more along the lines of font sets.

rberry88

Yeah, I thought that too when I first ran across the term, but no- "character" in this case refers to a device that can be accessed with no buffering/caching by the OS (as opposed to a block device). In other words, a data stream can be fed/read to/from a "char" device on a character-by-character basis as opposed to on a block-by-block basis. Serial ports (USB or traditional), keyboards, and mice are all examples of character devices.

Also, every device in Linux is given a major and minor device designation, hence the "char-major-188" designation. A full list of devices and their major/minor designations can be found in your /usr/src/linux/Documentation/devices.txt file.