Red Hat LINUX 7.2 Reference Manual page 91

Section 4.3:Directories in /proc
• super-max — Controls the maximum number of superblocks available.
• super-nr — Displays the current number of superblocks in use.
/proc/sys/kernel
This directory contains a variety of different configuration files that directly affect the operation of the
kernel. Some of the most important files include:
• acct — Controls the suspension of process accounting based on the percentage of free space
available on the filesystem containing the log. By default, the file looks like this:
4 2 30
The second value sets the threshold percentage of free space when logging will be suspended,
while the first value dictates the percentage of free space required for logging to resume. The third
value sets the interval in seconds that the kernel polls the filesystem to see if logging should be
suspended or resumed.
• cap-bound — Controls the capability bounding settings, which provide a list of capabilities
that any process on the system can do. If a capability is not listed here, then no process, no matter
how privileged, can do it. The primary idea is to make the system more secure by ensuring that
certain things cannot happen, at least beyond a certain point in the boot process.
The various values that are possible here are beyond the scope of this manual, so consult the kernel
documentation for more information.
• ctrl-alt-del — Controls whether
ing init (value 0) or force an immediate reboot without syncing the dirty buffers to disk (value
1).
• domainname — Allows you to configure the system's domain name, such as domain.com.
• hostname — Allows you to configure the system's host name, such as host.domain.com.
• hotplug — Configures the utility to be used when a configuration change is detected by the
system. This is primarily used with USB and Cardbus PCI. The default value of /sbin/hot-
plug should not be changed unless you are testing a new program to fulfill this role.
• modprobe — Sets the location of the program to be used to load kernel modules when neces-
sary. The default value of /sbin/modprobe signifies that kmod will call it to actually load the
module when a kernel thread calls kmod.
• msgmax — Sets the maximum size of any message sent from one process to another, which is set
to 8192 bytes by default. You should be careful about raising this value, as queued messages be-
tween processes are stored in non-swappable kernel memory, and any increase in msgmax would
increase RAM requirements for the system.
[Ctrl]-[Alt]-[Delete] will gracefully restart the computer us-
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