October 2008
Howto: ISP-style Email Server with Debian-Etch and Postfix 2.3
by camel (via)The configuration described here is not very complicated but still needs to be done carefully. You are expected to have at least basic knowledge of:
* MySQL (creating a database, granting access to users, basic SQL queries)
* SMTP (what it is and what a basic SMTP dialog looks like)
* POP3, IMAP (what they do and what the differences are)
* basic Postfix configuration (understand the default settings in your main.cf, have read through the basic configuration document and know that your mail log file is at /var/log/mail.log)
* Debian/Linux (general system administration, using a text editor, reading log files)
April 2008
PHP File Upload Configuration
by camelThough PHP presents a very versatile and user friendly interface for handling file uploads, the default installation is not geared for working with files in excess of 2 Mega Bytes. This article will help you configure your PHP engine for handling such large file transfers.
February 2008
Heartbeat2 Xen cluster with drbd8 and OCFS2
by camelThe idea behind the whole set-up is to get a High availability two node Cluster with redundant data. The two identical Servers are installed with Xen hypervisor and almost same configuration as Cluster nodes. The configuration and image files of Xen virtual machines are stored on drbd device for redundancy. Drbd8 and OCFS2 allows simultaneous mounting on both nodes, which is required for live migration of xen virtual machines.
This Article describes Heartbeat2 Xen cluster Using Ubuntu (7.10) OS, drbd8 and OCFS2 (Ver. 1.39) File system. Although here Ubuntu is used it can be done in almost same way with Debian
January 2008
Heartbeat2 Xen cluster with drbd8 and OCFS2 -- Ubuntu Geek
by camelThis Article describes Heartbeat2 Xen cluster Using Ubuntu (7.10) OS, drbd8 and OCFS2 (Ver. 1.39) File system. Although here Ubuntu is used it can be done in almost same way with Debian
Idea
The idea behind the whole set-up is to get a High availability two node Cluster with redundant data. The two identical Servers are installed with Xen hypervisor and almost same configuration as Cluster nodes. The configuration and image files of Xen virtual machines are stored on drbd device for redundancy. Drbd8 and OCFS2 allows simultaneous mounting on both nodes, which is required for live migration of xen virtual machines.
Using multiple network cards in XEN 3.0
by camelXen is great. But installing more than one network card became a pain when I tried it the first time. There are some documents describing the principle but I was unable to find a real life example somewhere else. So this is a summary about how it works here now.
Using a bridge for a Dom is generally a good idea but then all packets traversing the bridge can be intercepted by any Dom that is using the same bridge. Having a single network card in a Xen landscape also means that theoretically each Dom would be able to sniff all packets traversing this single network card including packets to and from other Doms. A solution is to have more than one network card attached to Xen using a single network card for a single dom.
The scenario described here has a server with 3 network cards installed. The first card should be used to access Dom0 and some other DomNs while the second and third network card should be used to purely access Dom1 rsp. Dom2. The Dom configuration file just needs to select the appropriate bridge for each dom.
October 2007
subcon - Google Code
by camelSubcon allows you to store your essential system configuration files in a subversion repository and easily deploy different configurations to machines in a cluster. It also features optional integration with SystemImager, enabling the deployment of system images and configuration in a single step. A flexible configuration file provides the ability to start, stop, or restart services or run arbitrary scripts when a change in a file or set of files is detected.
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