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 July 18, 2009

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.

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 9, 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.

Top 10 Linux Virtualization Software

Posted on in Categories Linux, Linux desktop, Linux distribution, Linux Scalability, Linux Virtualization, Networking, RedHat/Fedora Linux, Security, Solaris, Storage, Ubuntu Linux, UNIX, vmware, Windows server, xen last updated December 31, 2008

Virtualization is the latest buzz word. You may wonder computers are getting cheaper every day, why should I care and why should I use virtualization? Virtualization is a broad term that refers to the abstraction of computer resources such as:

  1. Platform Virtualization
  2. Resource Virtualization
  3. Storage Virtualization
  4. Network Virtualization
  5. Desktop Virtualization

This article describes why you need virtualization and list commonly used FOSS and proprietary Linux virtualization software.

Download of the day: Asus EEEPC Linux Software Development Kit ( SDK )

Posted on in Categories Hardware, Linux, Linux desktop last updated April 8, 2008

Asus has launched an open-source project for its cheap ASUS Eee laptop PC . You can download SDK and start developing more applications. It is a collection of programming tools, utilities, documentation, and libraries for Asus Linux EEEPc.

From the project home page:

This is an open-source project for ASUS Eee PC series. It provides a center for the community of Eee PC users and developers, including source code, documentation and experience sharing. The project is officially supported by ASUS.

=> Download Asus EEEPC SDK [ ISO / Vmware Images – 885 megabytes)

Why my Linux server ext3 filesystem go read-only?

Posted on in Categories Ask nixCraft, CentOS, File system, Linux, RedHat/Fedora Linux, Sys admin, Tips, Troubleshooting, Ubuntu Linux last updated August 28, 2007

From my mailbag:

We have 5 Dell server collocated running CentOS 4.x and 5.x server operating system. Sometime my file system (ext3) goes read-only. I’d like to know what could be causing such a problem?

My guess:
a) Hardware problem / hard disk problem, check harddisk for errors.

b) High disk I/O aka busy I/O retry error can mark low level disk call as failed. This will force ext3 to go into read only mode.

c) High disk I/O on SAN

d) SAN is not configured properly for the path failover.

In all sort of problems ext3 goes read-only to protect the filesystem and further damage. If you are using VMWARE, check out official webpage to download SCSI patches or workaround for vmware problems.

So what could be causing the file system on Linux go read-only?

Apart from above generic problem, any other error can trigger filesystem on Linux go read only. I hope our reader / seasoned Linux admin can help to answer this question. Please share the experiences and advice in the comments.

Howto: Create Shared Storage on Suse Linux using OCFS2 and Xen Virtualization

Posted on in Categories File system, High performance computing, Howto, Linux, Networking, Suse Linux, Sys admin, Tips last updated August 21, 2007

Arun Singh shows us how to create shared storage on SUSE Linux Enterprise Server 10 using OCFS2 (Oracle Cluster File System v2 for shared storage) and Xen Virtualization technology. Enterprise grade shared storage can cost you lots of money but here no real expensive shared storage used. The information provided here works with real shared storage as well:

This paper is to help you to understand the steps involved in creating shared storage without using expensive shared storage. Using this information you can create shared storage used by all xen guest OS and Host, avoiding copying of files between guest OS’s. Hope you will find this paper useful.

You can easily port instructions to Redhat or any other Linux distro without a problem. You can also use Redhat’s Global File System (GFS) too. We often use Fibre Channel or iSCSI, devices for GFS shared storage.

Creating shared storage on SUSE Linux Enterprise Server 10 using Xen and OCFS2 [novell.com]

On a related note there is also article about creating a highly available VMware Server environment on a Debian Etch system.