The ramblings of a technomuse
Linux
Linux: Howto download ISO files directly to a CD/DVD/BLU-RAY | Pétur Ingi Egilsson
Jul 23rd
It is possible to download .iso files directly onto a cd\dvd\blu-ray disk.
/dev/shm is a directory found on Debian & RedHat based distributions. (Please let me know if you find it on dists as well)
/dev/shm is a dynamic RAM disk, meaning it’s size will grow and shrink with the size of the files placed there.
Read it all here
CVE-2009-3547 (NULL pointer dereference and system crash)
Nov 9th
Synopsis: “Multiple race conditions in fs/pipe.c in the Linux kernel before 2.6.32-rc6 allow local users to cause a denial of service (NULL pointer dereference and system crash) or gain privileges by attempting to open an anonymous pipe via a /proc/*/fd/ pathname.”
Debian 5.x systems suffer from this vulnerability (with or without Wine installed), and the fix is easy.
At a root shell, do the following:-
sysctl -w vm.mmap_min_addr="1024"
# make it persistent cat <<EOF > /etc/sysctl.d/mmap_min_addr.conf # Prevent http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3547 vm.mmap_min_addr=1024 EOF
Full details at http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-3547
861 failed login attempts since Mar 8
Mar 13th
BBC team exposes cyber crime risk. The BBC report fails to mention what the makeup of the various systems they controlled was, and many pundits are assuming that it was mostly (if not entirely) Windows powered PCs that made up the 20,000 strong botnet, as Windows is by far the dominant PC operating system, and other platforms are not really targeted.
This of course is entirely untrue, its just that the Windows powered systems are the ones that are failing to repel the intruders!!. The server this site is hosted on is running Debian GNU/Linux 5.0, and since March 8th (6 days) there have been 861 failed ssh login attempts against it.
I’m using Shorewall as my firewall, and have restricted the number of ssh connections per second ftom the same ip address. This limits the number of attempts the crackers are able to make in said period, without having an impact on my normal external usage of this box. Prior to the modifications I made to the firewall rules, I was getting in excess of 10,000 attempts in the same period.
Thank you Shorewall, iptables/netfilter dudes.
Debian Debian Debian Debian
Mar 6th
Yes you heard me right, Debian. I used to hate it back before apt. Despite plenty of pressure from peers, I never got the “Debian” way, but with the release of Etch I decided I would give it another go; this time I would not be disappointed. Etch worked flawlessly, powering my server since late 2007. Mandriva is but a distant memory.
Now we have Lenny, and I may be at the point of not regularly running any other Linux distribution, save for trying them out. As I sit here making this post from my Debian server, I wonder has Lenny finally made my Ultimate Edition desktops all but redundant. Don’t get me wrong, I like Ultimate Edition & Ubuntu, but Lenny is all I need in a desktop Linux distribution, and these days my “desktop” boxes are rarely turned on.
I do all my mail, browsing, listening to music, and quite a bit of development using my “server”. A rock solid but desktop friendly Lenny has made it all but unnecessary to power up those desktop boxes, their sole purpose (having more powerful cpus) being development.
The “Universal Operating System” is no longer just for servers. 
Install ATI’s FireGL driver on Debian
Mar 5th
Kano (of Kanotix fame) provides this excellent script to install the latest ATI FireGL driver on yer Debian box. I have installed Debian Lenny x86_64 (5.0) on a new box with a AMD 780G chipset, that includes an on board HD3200 graphics processor.
Could I get the video working by installing the driver direct from AMD’s website?; eh no 
, and not only that but when I killed X with Ctrl+Alt+Backspace the box rebooted, and left my XFS filesystems in a bit of a state.
Kano’s script worked flawlessly, it did a variety of things:
- Installed build-essentials
- Installed GCC
- Installed dkms
- Downloaded the latest driver, built and installed a new .deb on my system
- Reconfigured X
- Restarted the login manager
/Me happy again
PS: you can see all of Kano’s excellent scripts here
Update: Power management seems to be broken with this driver, my monitor never turns off