Vmware Linux Guest Add a New Hard Disk Without Rebooting Guest

Posted on in Categories CentOS, fedora linux, Hardware, Howto, Linux, Linux desktop, Linux distribution, Linux Virtualization, RedHat/Fedora Linux, Storage, Sys admin, Tips, vmware last updated August 7, 2016

As a system admin, I need to use additional hard drives for to provide more storage space or to separate system data from user data. This procedure, adding physical block devices to virtualized guests, describes how to add a hard drive on the host to a virtualized guest using VMWare software running Linux as guest.

It is possible to add or remove a SCSI device explicitly, or to re-scan an entire SCSI bus without rebooting a running Linux VM guest. This how to is tested under Vmware Server and Vmware Workstation v6.0 (but should work with older version too). All instructions are tested on RHEL, Fedora, CentOS and Ubuntu Linux guest / hosts operating systems.

6 Tools To Find Out Website Load Speed

Posted on in Categories Apache, Beyond nixCraft, Business, Hardware, High performance computing, Howto, Linux, Linux desktop, Sys admin, Troubleshooting, UNIX, Windows, windows vista last updated November 5, 2009

Research shows that if your web pages take longer than 5 seconds to load, you lose 50% of your viewers and sales. As a UNIX admin often end users and web developers complain about website loading speed and timings. Usually, there is nothing wrong with my servers or server farm. Fancy java script and images / flash makes site pretty slow. These tools are useful to debug performance problems for sys admins, developers and end users. Here are six tools that can analyzes web pages and tells you why they are slow. Use the following tools to:

  • Make your site faster.
  • Debug site problem, especially client side and server side stuff.
  • Better user experience.
  • Improve the web.

20 Linux System Monitoring Tools Every SysAdmin Should Know

Posted on in Categories CentOS, Debian Linux, Howto, Linux, Monitoring, Networking, RedHat/Fedora Linux, Security, Sys admin last updated August 5, 2015

Need to monitor Linux server performance? Try these built-in commands and a few add-on tools. Most Linux distributions are equipped with tons of monitoring. These tools provide metrics which can be used to get information about system activities. You can use these tools to find the possible causes of a performance problem. The commands discussed below are some of the most basic commands when it comes to system analysis and debugging server issues such as:

  1. Finding out bottlenecks.
  2. Disk (storage) bottlenecks.
  3. CPU and memory bottlenecks.
  4. Network bottlenecks.

Increase Your VMware Virtual Hard Disk Size ( vmdk file )

Posted on in Categories Backup, Hardware, Howto, Linux desktop, Linux Virtualization, Storage, Sys admin, Tips, Ubuntu Linux, vmware, windows vista last updated June 18, 2009

I’ve Windows Vista installed as a guest under Ubuntu Linux using VMWARE Workstation 6.0. This is done for testing purpose and browsing a few site that only works with Internet Explorer. Since I only use it for testing I made 16GB for Vista and 5GB for CentOS and 5GB in size for FreeBSD guest operating systems. However, after some time I realized I’m running out of disk space under both CentOS and Vista. Adding a second hard drive under CentOS solved my problem as LVM was already in use. Unfortunately, I needed to double 32GB space without creating a new D: drive under Windows Vista. Here is a simple procedure to increase your Virtual machine’s disk capacity by resizing vmware vmdk file.

Linux Find Out If PCI Hardware Supported or Not In The Current Running Kernel

Posted on in Categories CentOS, Debian Linux, fedora linux, Gentoo Linux, GNU/Open source, Hardware, Howto, Linux, RedHat/Fedora Linux, Sys admin, Tips last updated June 18, 2009

From my mailbag:

How do I find out if a given PCI hardware is supported of by the current CentOS / Debian / RHEL / Fedora Linux kernel?

You can easily find out find out if a given piece of PCI hardware such as RAID, network, sound, graphics card is supported or not by the current Linux kernel using the following utilities under any Linux distributions.

Linux x86_64: Detecting Hardware Errors

Posted on in Categories CentOS, Debian Linux, fedora linux, Gentoo Linux, Hardware, Howto, kernel, Linux, Linux distribution, Networking, package management, RedHat/Fedora Linux, Shell scripting, Sys admin, Tips, Troubleshooting, Ubuntu Linux last updated June 18, 2009

The Blue Screen of Death (BSoD) is used for the error screen displayed by Microsoft Windows, after encountering a critical system. Linux / UNIX like operating system may get a kernel panic. It is just like BSoD. The BSoD and a kernel panic generated using a Machine Check Exception (MCE). MCE is nothing but feature of AMD / Intel 64 bit systems which is used to detect an unrecoverable hardware problem.

Program such mcelog decodes machine check events (hardware errors) on x86-64 machines running a 64-bit Linux kernel. It should be run regularly as a cron job on any x86-64 Linux system. This is useful for predicting server hardware failure before actual server crash.