All Posts By

oliver

When HA won’t play the way you want it to

By | Technical | No Comments

In an ideal world every service would support High Availability and Load Balancing, would scale up easily and cleanly and all of us systems administrators would be paid bucketloads to play golf all day while the computers did all the hard work. To quote Dylan Moran of Black Books fame, “Don’t make me laugh…bitterly”. I’ll cut to the chase – sometimes you have to really shoehorn technologies to do what you want. Fortunately I love doing this, and the technologies of today’s article are virtualised Windows 2008 on Xen, and Oracle XE 10g. Neither likes to play ball, for a few reasons: Generally speaking, when you virtualise an OS you want to have para-virtualisation drivers enhancing the hardware support. Open Source Xen has PV drivers, but they are not signed…

Read More

AusNOG conference

By | Company News, Technical | No Comments

I was lucky enough to get a free pass to the Australian Network Operators Group conference from one of our upstream providers, so that’s what I’m up to at the start of this week. It is interesting to compare it to my experiences at the several LinuxConfAU conferences I’ve been to. On the whole I can say it is more Enterprisey, far less smelly, and a generally smaller but more focussed conference. Obviously network topics dominate the conference (although there are a number of presentations that border on other areas). Somewhat confusingly for a sysadmin, they named this conference AusNOG03. They have decided to not use a year-based numbering system nor one that starts at 0 (which would please most of us), and as a kicker have locked themselves into…

Read More

Server naming schemes, part 5748

By | Technical | No Comments

Unusual, odd and downright disturbing naming schemes for servers have been almost literally done to death already. We at Anchor use a nautical theme, which has proven plentiful and seemingly inexhaustible over the few hundred servers and VPSs that we have under our control. Every now and then though, you come across something altogether new and astounding. Consider the documentation here which is linked to from this site. If you read through the PDF you’ll find the gem ZEUSDOGGYDOG. We are clearly dealing with a genius who has combined two distinct themes – Greek mythology (specifically, gods) and modern-era rappers. The namespace is almost inexhaustible (especially considering the current state of popular music)! I’ve come up with just a few examples: MARSNOTORIOUSBIG HADESFLAVAFLAV JUPITERDRDRE POSEIDONMETHODMAN HERMESICET I’m sure an automated…

Read More

It’s fricken cold in here Mr Bigglesworth

By | Company News, Technical | No Comments

If you’re in Sydney then you’ll be acutely aware of the extremes of temperature we are currently experiencing – and it’s only a few days after the start of Winter! Anchor is a carbon-neutral company and likes to promote environment-saving measures wherever possible so in our budget we allow for the purchase of thermal undergarments for each employee. A warm employee is a happy employee! By dressing smart for work, we don’t have to unnecessarily make use of heating systems, cutting down on electricity use and ultimately helping the environment. Plus, you look like a real coding ninja when typing at your workstation with fingerless gloves 🙂 If your place of employment doesn’t provide for something similar, ask your boss about it. Or if you’re an adept systems administrator, you…

Read More

Keeping your finger on the pulse of your network

By | Technical | No Comments

In the past I’ve written about a few ways you can set up decent IP traffic accounting on your network. If you have already set this up and are champing at the bit for more ways your can increase situational awareness of your network state you can try one of the following tools related to pmacct: http://www.pmacct.net/pnrg/ http://www.aptivate.org/Projects.BMOTools.pmGraph.html http://www.net-track.ch/opensource/pmacct-snmp/ http://code.google.com/p/netact/ http://projects.celuloza.ro/bwstat/ http://www.pmacct.net/fe/ http://sven.anderson.de/flox/ http://www.ntop.org/ http://bandwidthd.sourceforge.net/ http://nfsen.sourceforge.net/ http://etherape.sourceforge.net/ These tools allows you to graph and/or analyse your traffic data in a variety of ways. If you are currently using one or more of these, drop us a comment and let us know your success or failure stories!

Read More

Testing your connectivity

By | Technical | No Comments

Recently I blogged about our new IPv4 address allocation. While we don’t need to start using it for a while as we have been conserving IP addresses quite well, and gave ourselves plenty of time before we actually need to use the new allocation, it is a good idea to check that it is accessible to the Internet at large. Our new allocation is from the block 110.0.0.0/8 which was only allocated to the Asia-Pacific regional registry APNIC last November. Prior to it being allocated to APNIC, it would have been in a state affectionately known as “bogon” to network administrators. Bogons are network ranges that aren’t in use, and therefore can be safely ignored by all live networks on the Internet. There have been cases where spammers or other…

Read More

The importance of keeping clean log files

By | Technical | No Comments

I was shoulder-surfing a colleague today while they were trying to diagnose a webserver problem for a client. I noticed, certainly not for the first time, that the Apache error log message was filled with messages like “robots.txt not found” and “favicon.ico not found”. Surely these must be amongst the most frequently logged errors (if not the top two). Multiplied by many hundreds of servers, with millions of hits per day, and you have a significant amount of disk space being taken up by these trivial messages. What’s more, any time you spend scrolling through the hordes of messages like these is time taken away from debugging the real problem, if it exists. So please, be kind to your sysadmin and include a robots.txt and favicon.ico for your website. It…

Read More

New IPv6 allocation for Anchor

By | Technical | No Comments

As mentioned on this blog a few times before, we’re committed to getting IPv6 happening at Anchor. While the live rollout date is probably still a while away, we have at least begun making some inroads on the progress. Today we received our IPv6 allocation from APNIC: 2407:7800::/32 That equates to about 2^96 IP addresses, roughly 10^28 or 79228162514264337593543950336. Quite a mind-boggling number. We’ll continue our research, documentation, testing and will let you know when we are ready to start handing out live addresses. Until then, if you are a customer or would like to be, please let us know you are interested in IPv6, as there are still not too many hosting companies who are using it. Amazing, given IPv4 addresses will run out in a couple of years…

Read More

New IPv4 allocation for Anchor

By | Technical | One Comment

Nobody is under any pretences that IPv6 will be close to 100% usage globally any time soon, so despite many entities having firm IPv6 plans or infrastructure already in place, demand for IPv4 is still strong. With that in mind, we’ve just acquired a new allocation from APNIC which will hopefully see us through until IPv6 is dominant on the Internet. 110.173.128.0/19 This allocation is from the 110/8 class A that was allocated to APNIC in November 2008, and represents a tripling of Anchor’s current IPv4 space. We’ll be following our current strict allocation policies to ensure it is the last additional IPv4 allocation we will need, and continuing with our current IPv6 plans as all responsible entities on the Internet should be doing.

Read More

Covering all your bases

By | Technical | 2 Comments

No, this isn’t a pre-baseball game pep-talk. If you use configuration management (and you really, really should) then you will understand the need to manage configuration files. That may seem like a ridiculous statement but configuration files come in many shapes and sizes. What may be simple and consistent to one application author may be strange and erroneous to another. Thus the lowly sysadmin has the unenviable task of herding this heterogenous group of files into some semblance of order. With Puppet (a great configuration management application that Anchor uses) you have several options: roll out complete static files roll out templates which are filled in with common or possible per-host settings make file edits The last option is admittedly much more painful than the first two. Even here you have…

Read More