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ATA over Ethernet (AoE) (Ubuntu 12.04)

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This guide explains how you can set up an AoE target and an AoE initiator (client), both running Ubuntu 12.04. AoE stands for "ATA over Ethernet" and is a storage area network (SAN) protocol which allows AoE initiators to use storage devices on the (remote) AoE target using normal ethernet cabling. "Remote" in this case means "inside the same LAN" because AoE is not routable outside a LAN (this is a major difference compared to iSCSI). To the AoE initiator, the remote storage looks like a normal, locally-attached hard drive. read more...
mail this link | permapage | score:9668 | -falko, October 19, 2012

Using Multiple PHP Versions (PHP-FPM FastCGI) With ISPConfig 3 (Ubuntu 12.04)

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Since ISPConfig 3.0.5, it is possible to use multiple PHP versions on one server and select the optimal PHP version for a website. This feature works with PHP-FPM (starting with PHP 5.3) and FastCGI (all PHP 5.x versions). This tutorial shows how to build PHP 5.3 and PHP 5.4 as a PHP-FPM and a FastCGI version on an Ubuntu 12.04 server. These PHP versions can be used together with the default PHP (installed through apt) in ISPConfig. read more...
permapage | score:9641 | -falko, March 30, 2013

Tutorial: Debian 7 Samba Server with tdbsam

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This tutorial explains the installation of a Samba fileserver on Debian Wheezy and how to configure it to share files over the SMB protocol as well as how to add users. Samba is configured as a standalone server, not as a domain controller. In the resulting setup, every user has his own home directory accessible via the SMB protocol and all users have a shared directory with read-/write access. read more...
permapage | score:9627 | -falko, June 5, 2013

Installing FreeIPA with Replication

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Do you need a single point to add users within your organization for authenticating to multiple backends like your Linux servers? You've probably looked at OpenLDAP and found the same problem a lot of other users have: bad documentation and ridiculously hard to configure. Having done some installations of OpenLDAP in the past, the search was on to find a good alternative and more importantly, one that is far easier to do and has a good gui and CLI for adding users and groups. read more...
permapage | score:9592 | -falko, June 6, 2013

Apple DIY Repair

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I won't be buying any more Apple products. Here's why:

I'm generally capable of repairing my own equipment and can recognize when self-repair has been deliberately undermined. I recently had to replace a hard drive in an early generation white Intel iMac. Innocently, I believed the interior was accessible and serviceable in the manner of the externally identical white PowerPC iMacs.

No such luck. Not only do you have to remove the LCD to get to the hard drive, but you must also remove shielding around the LCD -- mostly by tearing it to bits. No doubt it is attached this way so that an authorized Apple technician will be able to confidently void your warranty if you've ever worked on the system yourself.

You'll also need a #10 torx magnetic screwdriver. And, no, #10 torx bits just won't do due to the narrow and deeply recessed screw holes. Also, since most torx screwdrivers aren't magnetic, you'll probably need to tape the screws to the screwdriver to reattach the LCD. Good thing there's a hardware store near you.

Oh, and don't forget to pick up some rubber cement to 'properly' reattach the hard drive temperature sensor while you're out looking for magnetic torx screwdrivers.

Considering the logical design of its predecessor and the tamper-evident shielding, I'm certain that this machine has been deliberately designed to prevent the owner from performing DIY upgrades and repairs.

While that is all quite annoying, at least working on the system is possible for someone with experience and determination.

Now, Apple has improved their anti-customer techniques with the 'Pentalobe' screw. It doesn't solve any problem but one: it'll keep customers from even being able to open the case.

If you're curious about Apple's evil new invention, you can read its rap sheet and view its mug shot here.
mail this link | permapage | score:9579 | -Ray, January 25, 2011

VPS: Xen vs. OpenVZ

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This is a short overview of the key differences between OpenVZ and Xen that you might consider when choosing a VPS. Note that this article is based on my opinions and that you must do your own research to determine which, if either, technology is best for you and your application.

First, some terminology. OpenVZ isn't fully virtualized and could be more properly referred to as a 'container', not a VPS. That shouldn't affect your choice. It's the technical differences that matter.

Cheap VPS offers are everywhere lately, it seems. However, upon closer inspection I saw that almost all of the low-priced offers were for OpenVZ. While both Xen and OpenVZ offer their advantages, I chose Xen. So, there's my first bias, right up front. :)

OpenVZ advantages:

  • Efficient (fast)
OpenVZ disadvantages:
  • Shared kernel (no custom kernel)
  • Shared memory with other users
  • Vendor can easily oversell, killing performance
Xen advantages:
  • Dedicated memory
  • fully virtualized (can run other kernels or even OS's)
  • vendor more limited in overselling
Xen disadvantages
  • Less efficient (more overhead due to a kernel-per-VPS)

You'll notice I left price out of the above comparison. In theory, there should be a small price advantage for OpenVZ. I don't know how big it should be but it pertains to two things: 1) Xen uses more memory due to each VPS having its own kernel, and 2) Xen uses more CPU, also due to the additional software layer required to virtualize the kernel.

In practice, however, the price gap appears larger than the above technical differences suggest it should be. I think the remainder of OpenVZ's price advantage is based on 1) the ability for a vendor to easily oversell OpenVZ, and 2) The price competition that results from some vendors overselling OpenVZ.

OpenVZ doesn't encapsulate its containers into a fixed amount of memory, so it runs processes in the host environment to monitor memory usage and kill processes as a container allocates more than its assigned amount.

As a result of this difference, loading down an OpenVZ container is problematic. To partially offset this disadvantage, most OpenVZ vendors offer 'burst' memory in addition to 'dedicated' memory. That is, the monitor process is set to allow the container to use more than its allocated memory -- for a short period of time. This messy situation results in a potentially unreliable environment as some of your processes may be arbitrarily killed -- at the busiest times.

Xen, on the other hand, allows the use of a swap space and excess memory allocation results in (hopefully) idle segments being rolled out to the swap area. While this is good for the memory-hungry VPS user, it can consume significant I/O capacity when memory is overallocated to the point of busy segments getting swapped out. This is bad for everyone sharing the underlying hardware.

I see Xen as clearly the superior technology. A Xen VPS feels and behaves more like a dedicated server. However, I still would have purchased OpenVZ at some price difference. After a bit of research, however, I located Xen VPS's at practically the same price as the cheapest OpenVZ containers. That made my decision easy.

With that said, keep in mind that a bad hosting vendor can ruin either technology through various means. Both technologies share the disk drives and I/O paths as well as the processor cores. Hardware can be poorly configured and managed in any case. A reputable vendor is probably the single most important consideration in choosing a virtual server.

Lastly, carefully check the 'allowed use' policy. Make sure your application is allowed on the server you intend to purchase. Note that due to their different characteristics, the allowed use policy may differ between OpenVZ and Xen for the same host. Also, it's good to understand the memory usage characteristics of your applications. If you know how much memory/swap they require on a physical system, it'll probably work with that same amount of memory/swap on Xen.

[I'll post a review shortly of my current VPS vendor and I will then add a link to that article here.]

mail this link | permapage | score:9565 | -Ray, June 13, 2011

Tutorial: Install Lighttpd, PHP5, MySQL on CentOS 6.4

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Lighttpd is a secure, fast, standards-compliant web server designed for speed-critical environments. This tutorial shows how you can install Lighttpd on a Centos 6.4 server with PHP5 support (through PHP-FPM) and MySQL support. PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation with some additional features useful for sites of any size, especially busier sites. I use PHP-FPM in this tutorial instead of Lighttpd's spawn-fcgi. read more...
permapage | score:9545 | -falko, April 17, 2013

ssh: Use Linux as a SOCKS5 proxy

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Did you know you could use ssh to create a SOCKS5 server?

This article explains how to create a SOCKS5 server in 1 command and how to add ip-based access control to it via iptables and tcp forwarder. read more...
permapage | score:9534 | -pkrumins, May 7, 2010

LAMP Tutorial: Apache2, PHP5, MySQL on Ubuntu 12.04 LTS

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LAMP is short for Linux, Apache, MySQL, PHP. This tutorial shows how you can install an Apache2 webserver on an Ubuntu 12.04 LTS server with PHP5 support (mod_php) and MySQL support. read more...
permapage | score:9533 | -falko, May 14, 2012

Server Monitoring With munin And monit On Debian Wheezy

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In this article I will describe how you can monitor your Debian Wheezy server with munin and monit. munin produces nifty little graphics about nearly every aspect of your server without much configuration, whereas monit checks the availability of services like Apache, MySQL, Postfix and takes the appropriate action such as a restart if it finds a service is not behaving as expected. The combination of the two gives you full monitoring: graphics that lets you recognize current or upcoming problems, and a watchdog that ensures the availability of the monitored services. read more...
mail this link | permapage | score:9525 | -falko, June 27, 2013

Tutorial: Ubuntu Jeos 12.04 LTS Spam Filter Gateway Server

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This tutorial shows how to set up an Ubuntu Jeos based server as a spamfilter in gateway mode. In the end, you will have a SpamSnake Gateway which will relay clean emails to your MTA. You will also be able to view your incoming queue, train your SpamSnake and carry out a few more advanced operations via Baruwa. read more...
permapage | score:9524 | -falko, December 23, 2012

Set up Qemu-Spice-Libvirt 0.9.6 USB Redirection on Ubuntu 11.10

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Iíve just built locally and uploaded to Launchpad Libvirt 0.9.6 via Debian Unstable, applying standard set of Ubuntuís patches updated for 0.9.6. It allows follow http://planet.spice-space.org/ update VMís XML profile under /etc/libvirt/qemu/ as suggested in second blog entry of Hans de Goede manage VMs via virsh or Virt Manager having USB redirection support active in Spicyís sessions. View for further details view my previous posting to Librenix. read more...
permapage | score:9509 | -Boris Derzhavets, October 17, 2011

Install MySQL 5.6, memcached on Ubuntu 12.10

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According to What's New in MySQL 5.6, MySQL 5.6 will bring some performance improvements over MySQL 5.5. If you want to test out MySQL 5.6, you have to install one of the development releases from the MySQL downloads page because there is no stable release yet. This tutorial explains how to install the MySQL 5.6.8rc1 (Linux Generic) development release on an Ubuntu 12.10 server. read more...
permapage | score:9505 | -falko, November 21, 2012

Tutorial: Run Ubuntu 11.04 Unity 3D on virtualbox 4

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Unity provides a complete, simple, touch-ready environment that integrations your applications and your workflow. Unity is designed for netbooks and related touch-based devices. It includes a new panel and application launcher that makes it fast and easy to access preferred applications, such as the browser, while removing screen elements that are rarely used in mobile and netbook computing. This tutorial will explain how to run unity under virtualbox. read more...
permapage | score:9499 | -gg234, April 25, 2011

Tutorial: Run Joomla 1.7 on Nginx on Debian 6, Ubuntu 11.10

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This tutorial shows how you can install and run a Joomla 1.7 web site on a Debian Squeeze or Ubuntu 11.10 system that has nginx installed instead of Apache (LEMP = Linux + nginx (pronounced "engine x") + MySQL + PHP). nginx is a HTTP server that uses much less resources than Apache and delivers pages a lot of faster, especially static files. read more...
permapage | score:9491 | -falko, December 15, 2011

Tutorial: Fedora 19 Samba server with tdbsam

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This tutorial explains the installation of a Samba fileserver on Fedora 19 and how to configure it to share files over the SMB protocol as well as how to add users. Samba is configured as a standalone server, not as a domain controller. In the resulting setup, every user has his own home directory accessible via the SMB protocol and all users have a shared directory with read-/write access. read more...
permapage | score:9477 | -falko, August 11, 2013

QEMU-KVM 1.0 patching for USB Redirection on Ubuntu 12.04

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Qemu-kvm 1.0 has been built based on branch
qemu-kvm-1.0-usbredir as of 12/29/2011. It contains all required usb redirection patches on top of QEMU-KVM 1.0 release

$ git clone git://people.freedesktop.org/~jwrdegoede/qemu
$ cd qemu
$ git checkout -B qemu-kvm-1.0-usbredir origin/qemu-kvm-1.0-usbredir
$ cd ..
$ cp -R qemu qemu-kvm-1.0-usbredir1 read more...
permapage | score:9465 | -Boris Derzhavets, December 31, 2011

How to install ajenti (like Webmin) on ubuntu 13.04 server

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Ajenti is a simple open source web based administration tool for managing ubuntu servers and this is similar to webmin.This is having nealy 35 plugins to monitor different servers (Including HTTP,DNS etc). read more...
permapage | score:9458 | -gg234, July 5, 2013

Build a Mail Server on CentOS 6 with Postfix, Dovecot, PostgreSQL

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We're going to set up a free, full-featured mail server on CentOS 6.2, all mail service related components are free and open source, and you have control over your own data. The installation process is extremly easy and smooth. read more...
permapage | score:9456 | -falko, April 29, 2012

Install Hyper-V Linux Integration Components on CentOS 5

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Microsoft has introduced together with Windows 2008 a new Hypervisor called Hyper-V. Initially Microsoft only supported Microsoft products and Novell Suse, but recently they added support for Red Hat Enterprise Linux. With this support it is also possible to install the components on CentOS. read more...
permapage | score:9455 | -falko, August 8, 2009
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Articles are owned by their authors.   © 2000-2012 Ray Yeargin