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When you create a VM Citrix Xen Cloud Platform (using a storage on Network or on local server) you assign a specific amount of space i.e. 20 GB or 30GB but after sometime client ask for more disk space you have to reboot the server to attach or add more disk space. In this post I will explain how you can add additional disk space to a Linux Xen VM without downtime.

Note: This method work if you have created Logical Volumes at the time of OS setup.

ADD ADDITIONAL DISK SPACE

1) Login to Xen Center and search the VM in which you want to extend the space.

2) Click on VM to open its section and go to Storage tab. You will see something like below image

Here you will see the position, name, description, size etc. of existing Disk (Virtual Disk).

3) Now click on “Add” which will show following window (Popup)

Here, Enter the Name, description and size of Disk you want to attach. Then select the location (list all the storage volumes added in the cloud or server) on which you want to create the disk. Press Add.

4) On VM properties (under storage tab) you will able to see the newly added disk.

CONFIGURE AND EXTEND DISK SPACE

1) Login to the server through SSH (Root User) and check Current disk space using command “df -h”

2) Execute command “fdisk -l” which will show all the current partitions on all the disks.

It will show “Disk /dev/xvdb doesn’t contain a valid partition table” which mean the server has detected the additional disk.

3) Now initialize the PhysicalVolume using command “pvcreate”

4) Add the above initialized PhysicalVolume to existing group with “vgextend”

5) Increase the size of existing Logical Volume using command “lvextend“.

6) Final step, without this step Linux will not detect the extended partition or space. Use command ” “resize2fs“ which will resize the file system and update kernel with extended space of logical volume.

Now check the disk space using “df -h” and you will able to see the increased disk space

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Eukhost has launched a cloud hosting services. Eukhost’s new cloud hosting services can help business or high availability requirements websites of all sizes more easily adopt cloud computing models to better manage data, lower hosting price and make collaboration easier with 100% uptime.

“Online business face a new set of competitions as they look to grow world wide integrated economy. A perfect storm of data deluge, a fluid regulatory environment and widening information technology (IT) skills gaps is creating additional cost pressures on top of already resource-strapped companies or organizations. As a result, online businesses are looking for latest strategies to gain more value out of their IT infrastructures and free up resources for strategic growth investments. So, we are moving our clients, to have a mixture of data and applications that live in the data center and in the cloud computing,” said Ryan Watson, Sales Manager, high performance and high availability on demand solutions. Eukhost’s cloud hosting strategy was inspired by feedback from their customer base indicating a growing desire to utilize data, applications and services with 100% uptime based on open standards.”

Eukhost’s ability to deliver cloud hosting services is made possible by technologies that include many features,100% uptime, Usage and Security. Offered as part of Eukhost’s services, these technologies give clients and the assurance of providing quality services from a cloud computing environment with the ability to monitor and log activity, charge-back and secure identity and access management protections.

New Eukhost’s cloud hosting services areas that utilize these technologies include:

VMware Fault Tolerance
VMware Hot Add
Performance and Scalability
VMware® Distributed Resource Scheduler (DRS)/VMware® Distributed Power Management (DPM)
VMware® Storage VMotion
VMware® VMotion
VMware® High Availability (HA)

It has been mentioned by Ryan Watson Sales that every applications and services are tested thoroughly before implementation, so chances of failure is next to to impossible.

For more information can be found at Eukhost Cloud hosting plans.

Soon eITwebguru will be surfed from the clouds of Eukhost Ltd :)

Today I received following email from Cpanel about Vulnerability in Exim Mail Server.

Summary

A memory corruption vulnerability exists in Exim versions 4.69 and older (CVE-2010-4344). Exim is the mail transfer agent used by cPanel & WHM.

Security Rating

This update has been rated as Important by the cPanel Security team.

Description

A memory corruption vulnerability has been discovered in Exim. This vulnerability may lead to arbitrary code execution with the privileges of the user executing the Exim daemon. cPanel previously released RPMs that mitigated the severity of the vulnerability on December 9, 2010 (CVE-2010-4345). This notification is for the release of new RPMs which remove the remote memory corruption vulnerability in its entirety. The vulnerability relies upon “rejected_header” being enabled (default setting) in the log_selector configuration.

Solution

To resolve and work around the issue on Linux systems, cPanel has issued new Exim RPMs. Server Owners are strongly urged to upgrade to the following Exim RPM versions:

Systems configured to use Maildir: Exim 4.69-26

Systems configured to use mbox (deprecated): Exim 4.63-5

Exim RPMs will be distributed through cPanel’s package management system. All cPanel & WHM servers receiving updates automatically will receive the updated Exim RPM during normal update and maintenance operations (upcp). To begin an Exim update on cPanel systems immediately, run the following command as root:

/scripts/eximup

FreeBSD systems should be running Exim 4.72 by default, which is not affected by this issue.

FAQ

This notification covers CVE-2010-4344.

The notification release earlier on December 10, 2010 with the summary “A privilege escalation vulnerability exists in Exim, the mail transfer agent used by cPanel & WHM.” covers CVE-2010-4345. At the time of the earlier announcement, the CVE had not been assigned.

For More information about this please check Cpanel

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