I am just going through the service-list of a server (CentOS 5) - the question will probably apply to other RedHat, Fedora, ... versions, too.
Note that my servers normally run in runlevel 3 (no GUI server processes started).
I stumbled across two services:
These two services get their configuration from /etc/sysconfig/readahead.d
The purpose of these services seems to be to preload certain files into cache-memory.
Browsing through the config-files (left at the default contents) I see mostly X11-related files and some libraries.
What is the deeper sense of these processes? AFAIK every file will go into cache-memory after the first read-access. Why should I preload - and why should I preload all these unneeded files?
IMHO this is a useless waste of read-bandwidth during start-up of the operating system.
I found that these readaheads will only cache the first inode-entries for the files listed (via the
fstat system call). So it just speeds up finding these files...
The question boils down to: Can I safely disable these services on a server, or am I missing something important here?
I Updated the header of the question accordingly, since the given answers don`t hit the mark yet.