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

last updated 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

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 required? How big should your Linux / UNIX swap space be?

Linux / UNIX: Find Out If a Directory Exists or Not

last updated in Categories CentOS, Debian Linux, File system, Gentoo Linux, Howto, Linux, Open source coding, programming, RedHat/Fedora Linux, Shell scripting, Suse Linux, Sys admin, Ubuntu Linux, UNIX

I’ve already written a small tutorial about finding out if a file exists or not under Linux / UNIX bash shell. However, couple of our regular readers like to know more about a directory checking using if and test shell command.

RAID 5 vs RAID 10: Recommended RAID For Safety and Performance

last updated in Categories File system, FreeBSD, Hardware, Linux, OpenBSD, RedHat/Fedora Linux, Storage, Suse Linux, UNIX, Windows server

A Redundant Array of Independent Drives (or Disks), also known as Redundant Array of Inexpensive Drives (or Disks) (RAID) is a term for data storage schemes that divide and replicate data among multiple hard drives. RAID can be designed to provide increased data reliability or increased I/O performance, though one goal may compromise the other. There different types of RAID levels. But which one you must use for data safety and performance considering that hard drives are commodity priced?

Nagios: System and Network Monitoring Book

last updated in Categories Book Review, Linux, Monitoring, RedHat/Fedora Linux, Suse Linux, Sys admin, Troubleshooting, Ubuntu Linux, UNIX, Windows server

The convenience and reliability that monitoring programs offer system administrators is astounding. Whether at home, commuting, or on vacation, admins can continuously monitor their networks, learning of issues long before they become catastrophes.

Nagios, the most popular open source solution for system and network monitoring, is extremely robust, but it’s also intensely complex.