Category Archives: Linux

Understanding Linux CPU Load – when should you be worried?

Posted on February 3, 2012 by admin

You might be familiar with Linux load averages already. Load averages are the three numbers shown with the uptime and top commands – they look like this: load average: 0.09, 0.05, 0.01 Most people have an inkling of what the load averages mean: the … Continue reading →

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Linux Local Privilege Escalation via SUID /proc/pid/mem Write

Posted on January 30, 2012 by admin

Introducing Mempodipper, an exploit for CVE-2012-0056. /proc/pid/mem is an interface for reading and writing, directly, process memory by seeking around with the same addresses as the process’s virtual memory space. In 2.6.39, the protections against unauthorized access to /proc/pid/mem were … Continue reading →

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Linux: Neighbour Table Overflow Error and Solution

Posted on January 1, 2012 by admin

I setup a CentOS Linux based Linux server running as a gateway and firewall server. However, I’m getting the following messages in the /var/log/messages log file: Dec 20 00:41:01 fw01 kernel: Neighbour table overflow. Dec 20 00:41:01 fw01 last message … Continue reading →

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Linux: Find Out What Partition a File Belongs To

Posted on January 1, 2012 by admin

How do I find out that /users/f/foo/file.txt file belongs to a specific partition? How do I find out on what partition a file exits? The df command report file system disk space usage including file names and directory names. The … Continue reading →

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CentOS / RHEL: Change / Copy File SELinux Security Context Command

Posted on January 1, 2012 by admin

I’ve created a file as follows: ls -l -Z /etc/cron.d/vnstat -rw-r–r–. root root system_u:object_r:system_cron_spool_t:s0 /etc/cron.d/vnstat I’ve created a new file /etc/cron.d/vnstat.custom.interface: ls -l -Z /etc/cron.d/vnstat.custom.interface -rw-r–r–. root root unconfined_u:object_r:system_cron_spool_t:s0 /etc/cron.d/vnstat.custom.interface The /etc/cron.d/vnstat is part of default vnstat package. I’ve installed … Continue reading →

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CentOS / RHEL: yum Command Reinstall Package

Posted on January 1, 2012 by admin

I accidental deleted the configuration file stored in /etc/ directory and the latest backup were made yesterday. How do I resinstall the package using the yum command under RHEL / CentOS Linux server? You can use the yum command with … Continue reading →

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Linux / Unix: Disable OpenSSH Host Key Checking

Posted on January 1, 2012 by admin

‘ve a remote Unix server running with OpenSSH remote login service. The openssh is configured for passwordless login using ssh keys. Our ISP allows to boot all Linux servers into the rescue mode. It allow us to bring a server … Continue reading →

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Live upgrade Fedora 15 to Fedora 16 using yum

Posted on January 1, 2012 by admin

Before we get started, I really ought to drop this here: Upgrading Fedora via yum is not the recommended method. Your first choice for upgrading Fedora should be to use preupgrade. Seriously. This begs the question: When should you use … Continue reading →

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Automatically upgrading to new point releases of Scientific Linux

Posted on January 1, 2012 by admin

When you install Scientific Linux, it will keep you on the same point release that you installed. For example, if you install it from a 6.0 DVD, you’ll stay on 6.0 and get security releases for that point release only. … Continue reading →

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Commvault Simpana 9.0 with Granular File Recovery for Linux under VMWare

Posted on January 1, 2012 by admin

I am currently going through the process of installing a brand new Commvault installation. One thing I am evaluating is doing most of my backups via the Virtual Server iDataAgent, this will give me “bare metal” recovery of my VM’s … Continue reading →

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