I’ve been getting a handful of emails offering me front-end jobs recently. Probably about time I admit that I like spending most of my time doing that, even though I ♥ my Rubies and I still believe developers who specialise end up worse off.
So I’ve decided to put down in words some thoughts…
Standard SNMP MIBs in Ubuntu and Debian
Due to the license being not completely free, the standard MIBs are no longer included with Debian and Ubuntu, as described by this ‘bug’ report.
You can fix that as follows:
sudo aptitude install snmp-mibs-downloader
Once you’ve done that you can query devices that support SNMP. My switch, for example, can be queried for some basic info about traffic that went through its ports:
snmpwalk -v1 -c public 10.192.168.252 IF-MIB::ifInOctets
snmpwalk -v1 -c public 10.192.168.252 IF-MIB::ifOutOctets
snmpwalk -v1 -c public 10.192.168.252 IF-MIB::ifDescr
You might be interested in other metrics, have a look at RFC 2863 to find more.
Hurricane Electric IPv6 Certification
The Hurricane Electric IPv6 Certification program. It’s free and it’s a fun and effective way to familiarize yourself with IPv6 concepts. Highly recommended for any technical person that has anything to do with ‘the Internet’.
If you don’t, I am confident you’ll build solutions for your clients that will at least partially break for IPv6-only users. And the changes you need to make to avoid this are small. The IPv6 certification programme (which I see more as a hands-on self-paced training lab) will help you point out what they are.
Your brain has to be IPv6 ready.
By the way, you get an ugly badge that you can show off with, FWIW. Here’s mine. :)
Quora - When you’re logged out you get a list of places where you’re still logged in with the option to log out
Shrink default ubuntu install by removing wireless
I have ubuntu running in a few virtual machines, and I have them at about 8 GB in size because that’s how big a default ubuntu server install is.
For some reason the default install also has the kernel header sources included, which didn’t seem very relevant to me. I decided to check out what packages I could also remove, and it turns out that my SERVER install also includes wireless support! Not very useful, certainly not in a virtual machine. So I removed it:
sudo apt-get remove wireless-crda
Apparently this was the only package that depended on the linux kernel sources, because these were also removed. This frees up about half a gigabyte of disk space!
Some of the other packages I removed from this machine: manpages, usbutils, wireless-tools and more. If you want to know what’s installed, try dpkg —list.
Path - When signing up as a new member, the iPhone app pulls your contact information from the address book.
/via Mark Oleszczak
A free e-book by Troy Hunt about the top ten web application security best practices, geared towards ASP.NET developers.
Fixing apt-get when your disk is full (Ubuntu, Debian etc)
If you run into a situation where there is ‘no space left on device’ when you run apt-get upgrade, then it suggests you do apt-get -f install. That won’t always fix it because well, there is no space left on the device!
If you’re lucky enough to be able to clean up some stuff so there is enough room, go ahead and do that. sudo apt-get -f install will fix things, after which you can proceed as intended.
On the other hand, if you feel stuck, try the following:
sudo apt-get install
Hopefully, this will show you some packages that have been obsoleted by the package you (or apt-get, actually) are trying to install just now. It can’t remove the packages because apt-get wants to install the new one first, for which there’s no space. Let’s say apt-get install shows the following output:
Reading package lists… Done
Building dependency tree
Reading state information… Done
The following packages were automatically installed and are no longer required:
linux-headers-3.0.0-12 linux-headers-3.0.0-13 linux-headers-3.0.0-12-generic-pae linux-headers-3.0.0-13-generic-pae
Use ‘apt-get autoremove’ to remove them.
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Now you can go by the list one by one, as follows:
sudo dpkg —remove linux-headers-3.0.0-12
sudo dpkg —remove linux-headers-3.0.0-13sudo dpkg —remove linux-headers-3.0.0-12-generic-paesudo dpkg —remove linux-headers-3.0.0-13-generic-pae
Note the package names above correspond to the ones mentioned by apt-get in the previous step. Yours will almost certainly be different.
You could also do them in one swoop as follows (I haven’t tried this:)
sudo dpkg —remove linux-headers-3.0.0-12 linux-headers-3.0.0-13 linux-headers-3.0.0-12-generic-pae linux-headers-3.0.0-13-generic-pae
Now, you can run sudo apt-get -f install and things will have been fixed, if enough space was cleared.
Hope this helps.
