Every week there’s a few announcements or articles which I find particularly interesting, and so I’ve decided to share them with you. I’m not a Unix guru (yet), but if any of the listed materials require further explanation – do feel free to ask and I’ll be glad to help.

Ubuntu 8.04.1 release

About a week ago, the first update to Ubuntu 8.04 was announced – Ubuntu 8.04.1 TLS. I have completed my experiment of using Ubuntu Hardy as my desktop OS a few weeks ago, and so haven’t upgraded yet – but I think this release is not so useful for anyone who’s been automatically updating their system – it’s just another milestone and a way to download a complete Ubuntu 8.04.1 as one image.

The highlights for me would be Firefox upgraded to the final 3.0 release and Gnome upgrade (it’s 2.22.2 in this release).

Gentoo Linux 2008.0 release

For some of you, it’s probably been a long-awaited release. Move to 2.6.24 kernel provided support for much more hardware, and this is bound to look good with the updated and much improved Gentoo installer.

Read more in the official Gentoo Linux 2008.0 announcement.

Cache poisoning vulnerability in DNS

Dan Kaminsky has found quite a nasty weakness in DNS implementations: deficiencies in the DNS protocol and common DNS implementations
facilitate DNS cache poisoning attacks.

Thanks to the seriousness of the problem and a great coordination, most of the vendors were given the time to publish a fix, so the Vulnerability Note VU#800113 contains a comprehensive list of vulnerable implementations of DNS (both server and client sides are affected, by the way!) and links to fixes provided by various vendors.

Whether you’re managing a server farm or just a Linux desktop – be sure to update!

Wine 1.1.1 release

Things are going much faster with Wine development after the 1.0 release – it didn’t take long for the 1.1 to appear, and now almost every other week brings another great update with tons of bugs fixed.

Wine 1.1.1 release includes more than 50 bugfixes and hundreds of changes since Wine 1.1.0, notably the fixes for Adobe Photoshop CS3 and Microsoft Office 2007 installers, as well as improved video playback and many other improvements.

If you’re logged in at some remote Linux system and need to quickly confirm the amount of available memory, there’s a few commands you will find quite useful.

free – free and used memory stats

free command is the most obvious choice for a first command when it comes to your RAM.

Simply run it without any parameters, and it will show you something like this:

ubuntu# free
             total       used       free     shared    buffers     cached
Mem:       4051792    4024960      26832          0      63768    3131532
-/+ buffers/cache:     829660    3222132
Swap:      4096492      43212    4053280

For this exercise, you’re only interested in the “total” column of the first line. 4051792 confirms that my home PC seems to have around 4Gb of memory available for Ubuntu to use.

Using dmesg to check memory size as recognized by Linux kernel

dmesg command shows you the last status messages reported by your OS kernel, and since every boot procedure includes scanning the hardware and confirming the devices and resources recognized by the kernel, you can see some basic information by using dmesg.

For our purpose, we need to filter out the memory stats:

ubuntu# dmesg | grep Memory
[   18.617904] Memory: 4043492k/5242880k available (2489k kernel code, 150360k reserved, 1318k data, 320k init)

Once again, the overall amount of memory confirms that 4Gb of RAM were still found during the last time my PC booted up.

Using /proc/meminfo to confirm the RAM size

/proc/meminfo is one of the special files managed by Linux kernel. It’s a clear text presentation of the most vital memory stats of your system (this means you can do something like cat /proc/meminfo to see all the parameters)

This is what you need to do to get the total size of your physical memory:

ubuntu# grep MemTotal /proc/meminfo
MemTotal:      4051792 kB

That’s it for today, enjoy!