Red Hat ENTERPRISE LINUX 3 Reference Manual page 88

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— Lists the number of allocated file handles, used file handles, and the maximum number
• file-nr
of file handles.
and
• overflowgid
with file systems that only support 16-bit group and user IDs.
— Controls the maximum number of superblocks available.
• super-max
— Displays the current number of superblocks in use.
•
super-nr
5.3.9.3.
/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:
— Controls the suspension of process accounting based on the percentage of free space
• acct
available on the file system containing the log. By default, the file looks like the following:
4 2 30
The second value sets the threshold percentage of free space when logging is 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 file system to see if logging should be suspended
or resumed.
— Controls the capability bounding settings, which provides a list of capabilities for
• cap-bound
any process on the system. If a capability is not listed here, then no process, no matter how privi-
leged, can do it. The 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.
For a valid
/usr/src/linux-2.4/include/linux/capability.h
bounding is available online at the following URL:
http://lwn.net/1999/1202/kernel.php3
— Controls whether [Ctrl]-[Alt]-[Delete] gracefully restarts the computer using
•
ctrl-alt-del
( ) or force an immediate reboot without syncing the dirty buffers to disk (
init 0
— Configures the system domain name, such as
• domainname
— Configures the system hostname, such as
• hostname
— Configures the utility to be used when a configuration change is detected by the system.
• hotplug
This is primarily used with USB and Cardbus PCI. The default value of
not be changed unless testing a new program to fulfill this role.
— Sets the location of the program used to load kernel modules. The default value is
• modprobe
/sbin/modprobe
— Sets the maximum size of any message sent from one process to another and is set
• msgmax
to bytes by default. Be careful when raising this value, as queued messages between pro-
8192
cesses are stored in non-swappable kernel memory. Any increase in
requirements for the system.
— Sets the maximum number of bytes in a single message queue. The default is
• msgmnb
— Sets the maximum number of message queue identifiers. The default is
• msgmni
— Lists the Linux kernel release number. This file can only be altered by changing the
•
osrelease
kernel source and recompiling.
— Displays the type of operating system. By default, this file is set to
•
ostype
value can only be changed by changing the kernel source and recompiling.
— Defines the fixed group ID and user ID, respectively, for use
overflowuid
list of values
which means calls it to load the module when a kernel thread calls
kmod
Chapter 5. The
for this virtual
. More information on capability
example.com
www.example.com
proc
File System
file, can be found
).
1
.
.
/sbin/hotplug
would increase RAM
msgmax
.
16
Linux
in
should
.
kmod
.
16384
, and this