SysAdminGear

What is slackpkg
slackpkg is a tool thtat syncs the OS with the SlackWare Disto mirrors.

Bom para começar vamos fazer o seu download:

# wget http://surfnet.dl.sourceforge.net/sourceforge/slackpkg/slackpkg-2.08-noarch-3.tgz
#
installpkg slackpkg-2.08-noarch-3.tgz

Configuring slackpkg:
cd /etc/slackpkg

In this folder you have 3 files
blacklist = packages to ingore on update
mirrors = to save bandwidh you should choose is possible a local mirror
slackpkg.conf = program configuration

First time you use this program, you should update the GPG key (you just to do this first time).

# slackpkg update gpg

How to use slackpkg

# slackpkg update (to sync)
# slackpkg install-new (packages
added)
# slackpkg upgrade-all (update all packages)

Other useful commands
Download package, install or re-install:

# slackpkg install reinstall

More information abou a package:

# slackpkg info

Good luck! :)

HOWTO Secure Data with PGP

Securing your data with PGP

PGP - Pretty Good Privacy
GPG - GNU Privacy Guard

Common Encryption Methods are WPA WEP SSL, these videos will show you how to secure your data with PGP

Secure Your Data with PGP - Video Part 1


Secure Your Data with PGP - Video Part 2

This video will show you how to run an operating system (Linux for example, dos, windows etc.) under Windows. You can of course run Windows Vista under your current system instead of Linux. Virtual system makes it good to test diffirent operating systems safely and easily.

How to - Run Linux Under Windows Video:

Run Linux Under WIndows Tutorial - Watch a funny movie here

This videos teachs a simple way to protect important files within their linux server, you can hidden directories.

Linux Hidden Directories Video:

Prevent Hackers Using Linux Hidden Directories - The top video clips of the week are here

How to create new linux partition video

Your NFS server is crashing? You have no problems when is reading but it cant write?

NFS was optimized and the only thing was updated Red Hat kernel v5.2 and CentOS 5.2 64 bit edition.

To fix this problem you should updated kernel packages. It will fix various security problems and bugs.

a 50-75% drop in NFS server rewrite performance, compared to Red Hat Enterprise Linux 4.6, has been resolved.

Read more at: Important: kernel security and bug fix update

Dont forget to run the next command:
# yum update

Build an embedded Linux distro from scratch tutorial

In this tutorial, you learn about cross-compiling, the boot loader, file systems, the root file system, disk images, and the boot process, all with respect to the decisions you make as you're building the system and creating the distribution.

Build an embedded Linux distro from scratch tutorial:
- Discussion of cross-compilation issues
- Review of the components of a Linux system and how they are put together
- Detailed steps for building, installing, and configuring the target system

Build an embedded Linux distro from scratch tutorial Objectives:
This tutorial shows you how to install Linux on a target system. Not a prebuilt Linux distribution, but your own, built from scratch. While the details of the procedure necessarily vary from one target to another, the same general principles apply. The result of this tutorial (if you have a suitable target) is a functional Linux system you can get a shell prompt on.

This tutorial assumes that your shell is a Bourne shell derivative; if you use a C shell derivative, the prompt will probably look different, and you will need to use different commands to set environment variables.

->Register now or sign in using your IBM ID and password.

(source: http://www.ibm.com/developerworks/linux/edu/l-dw-linux-embedded-distro-i.html)

This post will probably help you to fix an error occurring when you try to upgrade some package like this:

rpmdb: unable to join the environment
error: db4 error(11) from dbenv->open: Resource temporarily unavailable
error: cannot open Packages index using db3 - Resource temporarily unavailable (11)
error: cannot open Packages database in /var/lib/rpm
warning: /root/webmin-1.360-1.noarch.rpm: V3 DSA signature: NOKEY, key ID 11f63c51
rpmdb: unable to join the environment
error: db4 error(11) from dbenv->open: Resource temporarily unavailable
error: cannot open Packages database in /var/lib/rpm
rpmdb: unable to join the environment
error: db4 error(11) from dbenv->open: Resource temporarily unavailable
error: cannot open Packages database in /var/lib/rpm

How To Fix:

Remove Old Lock Files running this command:
# rm -f /var/lib/rpm/__db*

Now you have to rebuild RPM database:
# rpm -vv --rebuilddb

It should be fine now, if you want you can read more information at: http://www.rpm.org/hintskinks/repairdb/

Related to the post "Download ebtalbes filtering tool" you can also read this excellent tutorial "Configuring a Transparent Proxy/Webcache in a Bridge using Squid and ebtables".

Read the full article

First, boot the system with the first Linux CD, when you see boot prompt, type linux rescue to switch to rescue mode. Here, you will be asked if similar steps should be followed, which need to be followed in the installation.

At the prompt, type the next command:
# chmod /mnt/sysImage
# locate grub.conf
# nano /path/to/grub.conf (Edit the grub.conf file and remove the passwd line from the file)

When GRUB loads up, select the Red Hat Linux entry on the GRUB menu and then press "e" to edit the boot configuration.

Locate a line like this:

kernel /boot/vmlinuz-x.x.xx-x.xxx root=LABEL=/hdc

- type the number '1' at the end.

Doing so boots the computer into run level 1- single user mode you will automatically be logged in as root.

Type 'passwd' at the prompt, now you can enter a new password here.

HOW TO RESET ROOT PASSWORD

- While Booting (on Redhat ) press "e" in GRUB and you will find 3 lines of code.
- On 2nd line press "e"again and type "1" in the end (then "ENTER")
- Then press "b" and it will boot you into shell.
- Type "passwd" and change your root password.

SysVinit is a package that contains a group of processes that control the very basic functions of your system. It includes the init program, the first program started by the Linux kernel when the system boots. Init then controls the startup, running and shutdown of all other programs.

How to use RPM Commands

This is a post cointain some basic rpm commands to manage RPM packages.

1. Install a RPM package - you can use the command:
# rpm -ivh somepackage.arc.rpm

2. Uninstall a RPM package - you can use the command:
# rpm -e packagename
# rpm -e horde (e.g.)

3. Upgrade a RPM package - you can use the command:
# rpm -Uvh somepackage.arc.rpm
Note: When this command is used, RPM will uninstall the old version of package and install the new version.

4. Query a RPM package - you can use the command:
# rpm -q packagename
E.g.:
[root@box ~]# rpm -q glib
glib-1.2.10-15
Note: rpm -q command will print the package name, version, and release number of installed package. You can use this command to verify that a package is or is not installed on your system.

5. Package information - you can use the command:
# rpm -qi package
E.g.:
[root@box ~]# rpm -qi glib
Name : glib Relocations: (not relocatable)
Version : 1.2.10 Vendor: CentOS
Release : 15 Build Date: Tue Feb 22 05:32:17 2005
Install Date: Tue Mar 28 01:14:49 2006 Build Host: guru.build.karan.org
Group : System Environment/Libraries Source RPM: glib-1.2.10-15.src.rpm
Size : 321141 License: LGPL
Signature : DSA/SHA1, Sat Feb 26 20:42:07 2005, Key ID a53d0bab443e1821
Packager : Karanbir Singh
URL : http://www.gtk.org
Summary : A library of handy utility functions.
Description :
GLib is a handy library of utility functions. This C library is
designed to solve some portability problems and provide other useful
functionality which most programs require.

GLib is used by GDK, GTK+ and many applications. You should install
th glib package because many of your applications will depend on this
library.

As you can see, this command display package information, including name, version, and description of the installed program.

6. List files in package - you can use the command:
# rpm -ql package
E.g.:
[root@box ~]# rpm -ql glib
/usr/lib/libglib-1.2.so.0
/usr/lib/libglib-1.2.so.0.0.10
/usr/lib/libgmodule-1.2.so.0
/usr/lib/libgmodule-1.2.so.0.0.10
/usr/lib/libgthread-1.2.so.0
/usr/lib/libgthread-1.2.so.0.0.10
/usr/share/doc/glib-1.2.10
/usr/share/doc/glib-1.2.10/AUTHORS
/usr/share/doc/glib-1.2.10/COPYING
/usr/share/doc/glib-1.2.10/ChangeLog
/usr/share/doc/glib-1.2.10/NEWS
/usr/share/doc/glib-1.2.10/README
Note that this command will list all files in a installed RPM package. So it only works when the package is already installed on your system.

7. Check a RPM signature package - you use the command:
# rpm --checksig package
Note: This command will check the PGP signature of specified package to ensure its integrity and origin, it is secure to verify that ;)

Yum fails "GLib-CRITICAL"

[root@box ~]# yum check-update
Repository atomic is listed more than once in the configuration
Repository plesk is listed more than once in the configuration
Setting up repositories
update 100% |=========================| 951 B 00:00
base 100% |=========================| 1.1 kB 00:00
atomic 100% |=========================| 951 B 00:00
addons 100% |=========================| 951 B 00:00
extras 100% |=========================| 1.1 kB 00:00
Reading repository metadata in from local files

(process:7349): GLib-CRITICAL **: file gtimer.c: line 106 (g_timer_stop): assertion `timer != NULL' failed

(process:7349): GLib-CRITICAL **: file gtimer.c: line 88 (g_timer_destroy): assertion `timer != NULL' failed
Traceback (most recent call last):
File "/usr/bin/yum", line 29, in ?
yummain.main(sys.argv[1:])
File "/usr/share/yum-cli/yummain.py", line 97, in main
result, resultmsgs = do()
File "/usr/share/yum-cli/cli.py", line 534, in doCommands
ypl = self.returnPkgLists()
File "/usr/share/yum-cli/cli.py", line 1176, in returnPkgLists
ypl = self.doPackageLists(pkgnarrow=pkgnarrow)
File "__init__.py", line 904, in doPackageLists
File "/usr/share/yum-cli/cli.py", line 75, in doRepoSetup
self.doSackSetup(thisrepo=thisrepo)
File "__init__.py", line 260, in doSackSetup
File "repos.py", line 277, in populateSack
File "/usr/lib/python2.3/site-packages/sqlitecachec.py", line 40, in getPrimary
self.repoid))
TypeError: Can not create index on requires table: near "NOT": syntax error


Possible Solution "GLib-CRITICAL":

First try it:
# rpm -Uvh http://www.mirrorservice.org/sites/mirror.centos.org/4.6/os/i386/CentOS/RPMS/sqlite-3.3.6-2.i386.rpm http://www.mirrorservice.org/sites/mirror.centos.org/4.6/os/i386/CentOS/RPMS/sqlite-devel-3.3.6-2.i386.rpm

It should fix the problem, it worked on CentOS. If didnt, go to http://mirror.centos.org/centos/

And install or re-install the next packets:
- glib
- yum
- sqlite
- python-sqlite
- python-elementtree
- python-urlgrabber

Remember to use:
# rpm -Uvh somerpm.rpm

Linux partition possibility

A normal linux installation requires at least two partitions. It usually improves performance to more partitions.

Disk be divided into 4 partitions.
About 33% to linux bootable

About 33% to Windows bootable
Windows requires residency on the first primary partition

128M to swap
Note that a filesystem optimized for memory caching improves performance, that partition must have a filesystem supported by the operating system that will use it.

About 33% to data
This partition should be used by either or both OS if is compartible, it will be used for data, and can have any filesystem. The Windows bootable partition must be one of the filesystems supported by Windows, the linux bootable partition must be one of the filesystems supported by linux.

Setting up DNS servers on cPanel / other servers.

You should edit file /etc/resolv.conf
# nano /etc/resolv.conf

nameserver IP2
nameserver IP1

You can find at this post all Exploits of March / 2008 are now available. Keep your server protected against exploits :)

All 203 exploits added to Packet Storm in March of 2008 are available here:

Download March 2008 Exploits

Source: PacketStorm

Setup netboot on RHEL5.1

Note: system-config-netboot is not included in RHEL 5
A possible solution is download the Fedora rpm or other and use that.

The Fedora rpm is easily available and can be installed.

After kernel security patching or upgrade, Linux should be rebooted.

Ksplice is a GPL 2 Linux patch that provides Linux kernel security update and upgrades without reboot.

Tested on: kernel from 2.6.8 to actual version 2.6.25 and on Debain, Ubuntu, RHEl, Gentoo and other Linux distros.

Ksplice Download, Usage Examples and Documentation