Linux: Should You Use Twice the Amount of Ram as Swap Space?

Posted on in Categories data center, Debian Linux, fedora linux, File system, FreeBSD, Gentoo Linux, kernel, Linux, Linux desktop, Linux laptop, OpenBSD, RedHat/Fedora Linux, Solaris, Storage, Suse Linux, Tuning, Ubuntu Linux, UNIX last updated December 8, 2008

Linux and other Unix-like operating systems use the term “swap” to describe both the act of moving memory pages between RAM and disk, and the region of a disk the pages are stored on. It is common to use a whole partition of a hard disk for swapping. However, with the 2.6 Linux kernel, swap files are just as fast as swap partitions. Now, many admins (both Windows and Linux/UNIX) follow an old rule of thumb that your swap partition should be twice the size of your main system RAM. Let us say I’ve 32GB RAM, should I set swap space to 64 GB? Is 64 GB of swap space really required? How big should your Linux / UNIX swap space be?

Virtualization: Run Windows and Linux at One Place

Posted on in Categories Howto, Linux, Linux desktop, Linux Virtualization, Windows last updated January 24, 2008

I’ve used VMWARE ESX / Xen paravirtualization, Virtuozzo, Solaris Containers, and FreeBSD Jails as os level virtualization. Virutalbox is another full virtualization solution. Presently, VirtualBox runs on Windows, Linux and Macintosh hosts and supports a large number of guest operating systems including but not limited to Windows (NT 4.0, 2000, XP, Server 2003, Vista), DOS/Windows 3.x, Linux (2.4 and 2.6), and OpenBSD.

Virtualization: Run Windows and Linux at One Place

Rakesh has published a small article about VirtualBox Virtualization software. Both Windows and Linux can be run together simultaneously, and you don’t even need to switch between the two. With the seamless Windows feature of the latest version of VirtualBox virtualization software, you can seamlesssly run both Windows and Linux applications from the same desktop interface. This has been made possible by the combined efforts of VirtualBox and SeamlessRDP that is meant for seamless Windows support for rdesktop.

=> How to run Windows and Linux at one place? []

Mac ZFS Source Code Released

Posted on in Categories Download of the day, OS X, Solaris, Sys admin, Tips, UNIX last updated January 14, 2008

ZFS has amazing feature set and now it is ported to Mac

ZFS file system developed by Sun for its UNIX operating system. ZFS presents a pooled storage model that completely eliminates the concept of volumes and the associated problems of partitions, provisioning, wasted bandwidth and stranded storage. Thousands of filesystems can draw from a common storage pool, each one consuming only as much space as it actually needs. The combined I/O bandwidth of all devices in the pool is available to all filesystems at all times.

Apple has ported ZFS from Open Solaris to the Mac OS X platform. You can download ZFS beta version here (via ./).

Download of the day: Project Indiana OpenSolaris Developer Preview ISO

Posted on in Categories Solaris, UNIX last updated February 27, 2008

Project Indiana is working towards creating a binary distribution of an operating system built out of the OpenSolaris source code. The distribution is a point of integration for several current projects on, including those to make the installation experience easier, to modernize the look and feel of OpenSolaris on the desktop, and to introduce a network-based package management system into Solaris.

The resulting distribution is a live-CD install image, and is fully permissible to be redistributed by anyone. It will also have the capability for developers to create their own, customized distribution based on Project Indiana.

Now the first preview version is available. This is an x86-based LiveCD install image, containing some new and emerging OpenSolaris technologies. This may result in instabilities that lead to system panics or data corruption.

Among the features contained in this release are:

  • Single CD download, with LiveCD ‘try before you install’ capabilities
  • Caiman installer, with significantly improved installation experience
  • ZFS as the default filesystem
  • Image packaging system, with capabilities to pull packages from network repositories
  • GNU utilities in the default $PATH
  • bash as the default shell
  • GNOME 2.20 desktop environment

Download Project Indiana OpenSolaris Developer Preview ISO

=> Visit the official site to grab ISO file

Comparison: Linux and UNIX ~ ZFS vs XFS vs EXT4 filesystem

Posted on in Categories File system, Linux, Sys admin, Tips, UNIX last updated March 8, 2009

This is an interesting filesystem comparison. If you are looking to build cheap storage for personal use file system decision is quite important:

This is my attempt to cut through the hype and uncertainty to find a storage subsystem that works. I compared XFS and EXT4 under Linux with ZFS under OpenSolaris. Aside from the different kernels and filesystems, I tested internal and external journal devices and software and hardware RAIDs. Software RAIDs are “raid-10 near2” with 6 disks on Linux. On Solaris the zpool is created with three mirrors of two disks each. Hardware RAIDs use the Areca’s RAID-10 for both Linux and Solaris. Drive caches are disabled throughout, but the battery-backed cache on the controller is enabled when using hardware RAID.

=> ZFS, XFS, and EXT4 filesystems compared