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?

How To Reduce Linux Computer Power Consumption

Posted on in Categories GNU/Open source, Green Computing, Hardware, kernel, Linux last updated November 16, 2008

The Advanced Configuration and Power Interface (ACPI) specification is an open standard operating system-centic device configuration and power management. You can easily reduce your PC’s power consumption through smart activity monitors.

With the tools and code presented, you can reduce your power consumption through a series of rules regarding application usage. After tuning your kernel, hdparm, ACPI, and CPU settings, add these application monitors to more effectively enter your low-power states.

mount forcedirectio: Disable Linux CIFS / NFS Client Caching

Posted on in Categories CentOS, File system, GNU/Open source, kernel, Linux, Linux Scalability, RedHat/Fedora Linux, Storage, UNIX last updated November 16, 2008

If your network is heavily loaded you may see some problem with Common Internet File System (CIFS) and NFS under Linux. By default Linux CIFS mount command will try to cache files open by the client. You can use mount option forcedirectio when mounting the CIFS filesystem to disable caching on the CIFS client. This is tested with NETAPP and other storage devices and Novell, CentOS, UNIX and Red Hat Linux systems. This is the only way to avoid data mis-compare and problems.

Linux Supports More Devices Than Any Other OS

Posted on in Categories GNU/Open source, Hardware, kernel, Linux, News last updated November 3, 2008

Interesting read and claim has been independently verified by somebody from Microsoft.

Greg Kroah-Hartman is a longtime developer of the Linux kernel, known for his work maintaining USB drivers as well as for packaging the SUSE kernel at Novell. O’Reilly Media recently interviewed Greg about his claim that the Linux kernel now supports more devices than any other operating system ever has, as well as why binary-only drivers are illegal, and how the kernel development process works.

Read full interview: How Linux Supports More Devices Than Any Other OS, Ever