nixCraft Linux Sys Admin Blog

Posted: 24 Mar 2008 03:26 AM CDT

An experimental new design for Linux’s virtual memory system would turn a large amount of system RAM into a fast RAM disk with automatic sync to magnetic media. Most servers comes with 2-16 GB ram installed but not with a terabyte of installed memory (for 1TB+ ram go with IBM / Sun E25k server line). There is a new kernel patch called Ramback:

Ramback is a new virtual device with the ability to back a ramdisk by a real disk, obtaining the performance level of a ramdisk but with the data durability of a hard disk. To work this magic, ramback needs a little help from a UPS. In a typical test, ramback reduced a 25 second file operation to under one second including sync. Even greater gains are possible for seek-intensive applications. The difference between ramback and an ordinary ramdisk is: when the machine powers down the data does not vanish because it is continuously saved to backing store. When line power returns, the backing store repopulates the ramdisk while allowing application io to proceed concurrently. Once fully populated, a little green light winks on and file operations once again run at ramdisk speed.

However, this solution depends upon UPS:

If line power goes out while ramback is running, the UPS kicks in and a power management script switches the driver from writeback to writethrough mode. Ramback proceeds to save all remaining dirty data while forcing each new application write through to backing store immediately.

Download Of The Day: Ubuntu Linux 8.04 (Hardy) Beta ISO / CD

Posted: 24 Mar 2008 03:04 AM CDT

The Ubuntu project has released beta version 8.04 and available for download from the official project web site.
The Ubuntu developers are moving very quickly to bring you the absolute latest and greatest software the open source community has to offer. New feature includes:

+ GNOME 2.22

+ Linux kernel 2.6.24.

+ Firefox 3 beta

+ PulseAudio

+ Vinagre VNC client

+ Brasero CD/DVD burning application

+ There is a new installation option for Windows users. Wubi allows users to install and uninstall Ubuntu like any other Windows application. It does not require a dedicated partition, nor does it affect the existing bootloader, yet users can experience a dual-boot setup almost identical to a full installation.

The final stable version will be released in April 2008. Download cutting edge version from official mirror.