02-18-2013
Under VM, not dirty pages stay mapped in case anyone wants to read them through a mmap(). If you need a page, they can be taken, but they are not free. You can run a job that mmap()'s a file, read the whole file into ram, exit, run it again, and when it mmap()s the file again, the old pages are mapped into the new process memory range and it runs much faster. This is what happens with libc.so: everyone runs printf() from the same ram page.
8 More Discussions You Might Find Interesting
1. Linux
New to the forum.
I am running CentOS release 5.3 (Final) and have run into a unique situation.
I have been able to determine that we have a swap memory leak due to an issue with an asterisk server. This specific issue takes approximately 2-3 months for enough of the swap to to be used before... (1 Reply)
Discussion started by: g0neinsane
1 Replies
2. Red Hat
hi
i've notice a huge problem on my newly installed centOS server and i have no idea how to solve it and where to start..
memory on server 3 GB and it goes down, down, down..
after reboot it shows 71mb used
after a hour its 76mb
and after 24h it's around 200
later = more
i have NO idea... (7 Replies)
Discussion started by: tip78
7 Replies
3. Red Hat
HI All,
I am trying to setup DNS on my centOS server.
I am using bind software to setup DNS.
The following errors have getting.
==================================================
Error in named configuration:
zone localdomain/IN: loaded serial 42
zone localhost/IN: loaded serial 42... (4 Replies)
Discussion started by: phpconnect
4 Replies
4. Red Hat
I have compiled a new kernel (3.2.9) for centos 4/5/6 servers. There is an issue with the centos 4, 32 bit servers. The kernel changes the order in which the MAC address is determined and because of this the server network does not come up as the wrong MAC address are assigned. Even if we specify... (6 Replies)
Discussion started by: anil510
6 Replies
5. UNIX for Advanced & Expert Users
Hi,
We are configuring Freeipa for our LDAP system.
Things seem to work okay when we try and log in with our domain accounts on the LDAP server. But when we try to loggon to the slave it closes the connection.
There is an option in authconfig-tui to configure IPA. However, the senior admin... (0 Replies)
Discussion started by: mojoman
0 Replies
6. Filesystems, Disks and Memory
Hi,
i have just installed 4 gb RAM ddr3 on OS Windows 7 32 bit.
In "manage peripherals" i see this section:
Memory installed (ram) : 4,00 gb (2,30gb usable)
Why only 2,30 gb usable ?
In Windows 7 32bit the maximum size is not 3,00gb ?
see file attached, please (4 Replies)
Discussion started by: nash83
4 Replies
7. UNIX for Advanced & Expert Users
Hi,
Which tools or method is popular, simple and effective, to check memory such as bad sector, throughput and performance?
Thank you.
- j (5 Replies)
Discussion started by: hce
5 Replies
8. AIX
Hi,
Can anyone explain this please.....
A simple test program...
### snip
#include <stdio.h>
main() {
static int n;
n = 6;
printf("hello %d\n", n);
n=7;
}
### snip
64 bit compile/link.... (2 Replies)
Discussion started by: bagpussnz
2 Replies
LEARN ABOUT CENTOS
osinfo-query
OSINFO-QUERY.C(1) Virtualization Support OSINFO-QUERY.C(1)
NAME
osinfo-query - Query information in the database
SYNOPSIS
osinfo-query [OPTIONS...] TYPE [CONDITION-1 [CONDITION-2 ...]]
DESCRIPTION
The "osinfo-query" command allows extraction of information from the database. TYPE can be one of "os", "platform", "device", or
"deployment". With no conditions specified, all entities of the given type will be listed.
# List all operating systems
$ osinfo-query os
Short ID | Name ...
----------------------+-----------
centos-6.0 | CentOS 6.0 ...
centos-6.1 | CentOS 6.1 ...
...
Conditions allow filtering based on specific properties of an entity. For example, to filter only distros from the Fedora Project, use
# List all operating systems
$ osinfo-query os vendor="Fedora Project"
Short ID | Name ...
----------------------+--------------
fedora1 | Fedora Core 1 ...
fedora2 | Fedora Core 2 ...
...
The set of fields which are printed can be controlled using the "--fields" command line argument:
# List all operating systems
$ osinfo-query --fields=short-id,version os vendor="Fedora Project"
Short ID | Version
----------------------+----------
fedora1 | 1
fedora2 | 2
...
OPTIONS
-s PROPERTY, --sort-key PROPERTY
Set the data sorting key. Defaults sorting the first column
-f PROPERTY1,PROPERTY2,..., --fields PROPERTY1,PROPERTY2,...
Set the visibility of properties in output
PROPERTY NAMES
OS
Valid property names for the "os" type are:
short-id
The short OS identifier
name
The long OS name
version
The OS version string
family
The OS kernel family
vendor
The OS vendor
release-date
The OS release date
eol-date
The OS end-of-life date
codename
The OS code name
id The OS identifier
PLATFORM
Valid property names for the "platform" type are:
short-id
The short platform identifier
name
The long platform name
version
The platform version string
vendor
The platform vendor
release-date
The platform release date
eol-date
The platform end-of-life date
codename
The platform code name
id The platform identifier
DEVICE
Valid property names for the "device" type are:
name
The device name
product
The device product name
product-id
The device product ID string
vendor
The device vendor name
vendor-id
The device vendor ID string
class
The device type class
bus The device bus type
id The device identifier
DEPLOYMENT
Valid property names for the "deployment" type are:
id The deployment identifier
EXIT STATUS
The exit status will be 0 if matching entries were found, or 1 if not matches were found
SEE ALSO
"osinfo-db-validate(1)", "osinfo-detect(1)"
AUTHORS
Daniel P. Berrange <berrange@redhat.com>
COPYRIGHT
Copyright (C) 2012 Red Hat, Inc.
LICENSE
"osinfo-query" is distributed under the termsof the GNU LGPL v2+ license. This is free software; see the source for copying conditions.
There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
libosinfo-0.2.7 2013-02-06 OSINFO-QUERY.C(1)