VMware and Citrix are peers in the market for virtualized standard servers. The two global players recently introduced new versions to keep their opponents on their toes. In this article, we compare the two products and evaluate the high-availability and monitoring strategies.
PHP Shell and Shell In A Box put a shell in your browser, thus facilitating web server management – even from the nearest Internet cafÈ and without SSH access.
pfSense is inconspicuous at first glance but impressive when you take a closer look. Even advanced features like high availability are part of its repertoire – not bad for a small firewall.
Nagios might be the best known free monitoring tool, but Zabbix has steadily gained ground over the years and is now set to challenge the market leader. In this article, we look at basic Zabbix functionality and introduce you to items, triggers, and actions.
As a replacement for the legacy System V init, Upstart has abandoned many concepts: Instead of runlevels, Upstart has jobs and events, and its ability to start services in parallel considerably accelerates the boot process. Yet, configuration is almost child's play.
In emergencies, administrators need to know as quickly as possible whether computers in a private cloud are failing. A simple setup with KVM, Pacemaker, DRBD, and Opsview will help keep watch.
With the command-line tool virsh, a part of the libvirt library, you can query virtual machines to discover their state of health, launch or shut down virtual machines, and perform other tasks – all of which can be conveniently scripted.
Performance is very much a hot topic in monitoring environments. In this article, we look at some Nagios performance benchmarks and compare Nagios with some other monitoring alternatives.
Admins who want to leverage the powers of Pacemaker rely on OCF resource agents to monitor the cluster. If you don't have an agent for a specific application, try writing your own.
Cl uster filesystems such as GFS2 and OCFS2 allow many clients simultaneous access to a storage device. Along with DRBD and Pacemaker, this offers a low-budget option for creating a redundant service – but you need to watch out for a couple of pitfalls.
Monitoring is similar to backup: It is not a question of whether or not to monitor, but how. The solution to this problem is to have a good strategy with the right priorities and the right tools.
Debugging the kernel of a running operating system has always been tricky, but now the Qemu emulator supports cross-platform kernel and module debugging at the programming language level.
Fixed partitions on a Linux system can be created easily using tools such as fdisk, but the assignments tend to be wrong or the partitions too small at the worst possible moment. LVM requires slightly more effort at install time, but it soon pays dividends.
The latest gadget lies temptingly on the table in front of you, but it doesn't work with the Linux distribution you are currently using. What now? This month's Admin Story is all about modifying standard Linux packages.
