Wednesday, 25 November 2009

Backup Regime

I've updated how my backup regime works and I wanted to write it all down to make sure that it is clear in my head. The overview is to make sure that I have two copies of all media as quickly as possible and then move a third backup into the cloud. I use about 1 gig of new disk space each month, mostly from pictures and videos. The steps to get this backed up are:
  1. Put the source media, SD cards, into read only mode
  2. Copy the media into a new folder under a single 'media' folder on my desktop with the name of the folder being the date when I'm doing the backup
  3. Immediately copy the new folder onto an external USB hard drive
  4. Remove the hard drive from the desk top
  5. Kick off a backup. I'm using Jungle Disk for my cloud backups
  6. Put the SD card into read-write mode and delete all content to free up space
  7. That's it
I'm going to use the OVI files space I have for syncing docs between computers for the time being.

Friday, 13 November 2009

Giving up on Google Wave

I've been playing with Google Wave for just over a week now and I think I've seen enough. I just can't find anything practical for it to do. I feels very much like a technology searching for a problem to solve. It reminds me very much of Joel Spolsky's post on Architect Astronauts.
Robert Scoble, who I don't actually follow, has a nice post pointing out that Wiki's would be a better solution to many Google Wave's supposed use cases.
Feel free to tell me I'm wrong. I'll try to keep an open mind.

Tuesday, 3 November 2009

Speeding up Webpage with YSlow

I help my sister-in-law by looking after the hosting of the web site for their company 'Out and About'. After they recently updated their content I decided to have a play with Yahoo's YSlow Firefox extension to make sure I'd got everything running as smoothly as I could. There were several server related issues that I fixed quite easily. I had most problems sorting out the expires headers on the static content. I run the lighttpd webserver to host the site. In order to get the expires header I had to enable mod_expire and make sure it was the first module listed. The in the web page virtual host entry I added: expire.url = ("" => "access 1 months") ...this is to put a long expires header for the whole site contents as it is all static. With this in place YSlow scores me an "A". The initial page load takes about 4s and subsequent navigations take about 75ms while the Google Analytics component loads.

Friday, 23 October 2009

Midnight Commander for Editing on E71

I use putty on the E71 to ssh into various server to do sys admin type things and also to do a little python programming remotely. I'd not found a nice unix editor to work over putty from the limited keyboard on the phone. Recently I started playing around with Midnight Commander (mc). It turns out that the internal editor to Midnight Commander, mcedit, is actually reasonably easy to use on the E71.

Tuesday, 20 October 2009

Geocaching on the Nokia E71

I was just typing up my thoughts about how to use the Symbian Python interpreter on the Nokia E71 to write a quick and dirty Geocaching application using the phone's GPS when a Google search found 'Geocaching Live'. I'm going to give that a go first.

Review of Land of Play

Our younger two kids and I, aged four and nearly two, had a very nice Monday morning at the Land of Play in Manchester's Trafford Park. The place is very new, as of October 2009, and all the equipment is practically pristine. The unique selling point of Land of Play is the electric go-karts. Both kids loved them. The four-year-old was off on his own one and I could sit on the tail fin of the two-year-old's correcting the steering as subtly as possible. There was the standard climbing activity area, of medium size compared with the others of our acquaintance. The climbing was fine for the two and four-year-old, but would have been too easy for our seven-year-old.
The entrance fee was very reasonable. It was about £4.50 each after a 10% discount coupon that the Google Maps entry for the company offered me. The kart rides cost another £1 each, but you got a reasonable length go for the money. It has a cafe serving reasonably priced, if basic grub.
The main disappointment for me was that the environment didn't manage to shake off the feeling of industrial park. Sure it was clean, but there was only a passing attempt made at child-friendly decoration. That said I think we liked it enough to make another visit.

Wednesday, 14 October 2009

Friday, 2 October 2009

Fire Balloons

Inspired by Roald Dahl's 'Danny Champion of the World', we've decided that our current project is to make a fire balloon. In the book, Danny and his father make a balloon out of tissue paper, wire and a cotton wool ball soaked in meths. Our first attempt copied this pattern. We used fuse wire to hold the wool and made a cylindrical envelope out of tissue paper. Unfortunately on an attempted launch we had a spectacular, if predictable failure with the tissue paper going up in flames.
There has been many discussions about the causes of the failure. The key problem seems to have been that the fuse wire was rigid enough to support a dry ball of cotton wool but the weight of the meths caused the wire to bend. Design efforts are now focusing on the fuel-holding mechanism. One theory is that we can use wooden cocktail sticks. The objection is that the wood will burn through before the meths has run out. We think we're going to try an experiment to find out. That should be fun!

Sunday, 27 September 2009

DNS Trouble

I was alerted by the nice people at SiteUptime that my website had stopped working at about 7:30am this morning. I had planned to go jogging with my dad and had friends coming over for lunch. I just had time to get on to putty to see if I could see what was going on. Lighttpd wouldn't start -- complaining that it couldn't resolve the domain name. A few ping attempts later it was clear that nothing would resolve. I didn't have time to figure out what had happened, but the support at RimuHosting is really superb. I sent them a support ticket and within 30 minutes their techie had updated my /etc/resolve.conf with their newest DNS cache servers and everything was working again. I can't recommend RimuHosting highly enough! They have a nice script to fix the resolv.conf in case you were wondering :-)

Monday, 21 September 2009

First Geocache Published

In a very proud family moment we've just published our first ever Geocache. You can find it on the Geocaching web site with the ID GX1YXPO. The first two people have already found it. The first one got to it at 0745 the morning after the listing went live. A Monday too!

How to Copy URL from Symbian Web Browser

I've finally figured out how to cut'n'paste from the standard Symbian Web Browser on my E71 phone. On the E61, my previous phone, I installed the Opera browser which gave me easy access to copy the current URL. I've not bothered to install Opera on the new phone. The Symbian browser lets you look at the current page URL using the Tools >> Page Info setting but has no way of copying. The solution I found was to bookmark the page that I wanted the URL of and then edit the bookmark. From the edit bookmark page a simple CTRL-A and CTRL-C did the trick.

Wednesday, 9 September 2009

Maths Lament and Dice Games

One of the home ed lists I'm on pointed me at this wonderful maths essay: It is the sort of thing that makes you (ok, makes *me*) yearn to be a mathematitican. A passage half-way through got me thinking: "SIMPLICIO: Then what should we do with young children in math class? SALVIATI: Play games! Teach them Chess and Go, Hex and Backgammon, Sprouts and Nim, whatever. Make up a game. Do puzzles. Expose them to situations where deductive reasoning is necessary. Don’t worry about notation and technique, help them to become active and creative mathematical thinkers." That struck a chord. Our eldest is now seven and although very good at mental addition and subtraction, we're struggling to get him interested in multiplications or any writing. (I know I shouldn't worry, but that's easier said than done.) Then I had an idea. He loves cricket, could I make up a game that would need multiplication and involved cricket. What I came up with was to throw three six-sided die and multiply the resulting numbers to get each batsman's score. E.g {2, 4, 3} results in a score of 24. You then of course need to add up the scores to get the team result. This game in hand #1 son wrote down all of the names of the English and Australian cricket teams (I helped with spelling) and did lots of multiplication. Past experience says this game will stick for a week or two then we'll be on to the next thing. Has anyone got any pointers to other games that need multiplication as part of the game play? Any suggestions for other simple dice-based sports simulations?

Wednesday, 26 August 2009

E71 New Phone and Ovi

I have a new nokia E71 for my birthday from my ever-loving wife and it is great. Will post more later about things I'm going to put on it. For now I'm signing up for 'Ovi' from nokia, I wanted something to sync up file from my PC and phone. I've signed up to a phone account and got some desktop software installed on the PC. I'll try it out over the next couple of days and report back here on how I get on.

Wednesday, 24 June 2009

apt gpg Key Problem

I run a few Debian machines and I use aptitude on all of them to keep the packages up to date. Recently on one machine only I've been getting gpg key errors. In fact it is the server that I have with Rimu Hosting (great guys) that suddenly started presenting the error:
W: GPG error: stable Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 9AA38DCD55BE302B W: There is no public key available for the following key IDs: 9AA38DCD55BE302B
To list the keys that I know about I run 'apt-key list':
/etc/apt/trusted.gpg -------------------- pub 1024D/2D230C5F 2006-01-03 [expired: 2007-02-07] uid Debian Archive Automatic Signing Key (2006) pub 1024D/6070D3A1 2006-11-20 [expires: 2009-07-01] uid Debian Archive Automatic Signing Key (4.0/etch) pub 1024D/ADB11277 2006-09-17 uid Etch Stable Release Key pub 1024D/BBE55AB3 2007-03-31 [expires: 2010-03-30] uid Debian-Volatile Archive Automatic Signing Key (4.0/etch) sub 2048g/36CA98F3 2007-03-31 [expires: 2010-03-30]
Like the program says, I'm missing a key. I tried the keyserver to import the key: sudo gpg --keyserver --recv-key 55BE302B ...and then export that key into apt's key list: sudo gpg -a --export 55BE302B | sudo apt-key add - That done, I run aptitude and I can now happily install my security updates.

Tuesday, 5 May 2009

Notes from Linux Magazine - May 2009

  • Graphics design book using FLOSS tools available from
  • Hyperic HQ looks an interesting tool for enterprise monitoring.
  • 'Beginning Portable Shell Scripting' from Apress looks like a good book.
  • WebHTB is a tool to manage network bandwidth allocation, although it does seem to need kernel modules compiled in first.
  • agedu is a handy tool for finding old files in a file system
  • Here's a list of fuzzing tools:<
    • mangleme
    • browser fuzzer 2
    • fzem
    • fsfuzzer
    • FileP
    • ProxyFuzz
    • Peach Fuzzing Platform
    • GPF
    • SPIKE
    • QueFuzz
  • Fsniper processes new and updated files for you
  • Chandler is interesting again. Might be the way to put the calendar, email and contact lists for the family together. Might need to run a Chandler Hub.
  • Security web sites to take a look at
    • InvisibleThings
    • Matasano
    • The Fake Name Generator
    • The Milw0rm exploit database
  • Take a look at the digital subscription options at
  • Linux Magazine is published from Manchester. Add that to the list of reasons for civic pride.

Monday, 4 May 2009

How did the man at the Termini Station in Rome con us by typing in a number into the ticket machine?

The wife and I recently went to Rome for our tenth wedding anniversary. As is typical of our travels without children, we didn't really leave enough time to get from the hotel to the airport to get back home. We were doing battle with the automated ticket machine at the Termini station when a man approached us and offered to help. Now the con-artist alarm bell should have been going off at this point, but we were really late and so we ignored it. He pressed the buttons and got the ticket that we wanted for the correct price. Only one thing was odd: as part of the booking process he typed some number into the automatic ticket machine. Neither the wife nor I were quick enough to see what the number was for. It was about 6-10 digits and he had memorized it. We can't see how we've been conned here but it must have happened. My wife thinks it was a loyalty card scheme. I'm not convinced. Anyone with any ideas please leave a comment?

Sunday, 26 April 2009

'Upgrade' Killed my ADSL

My ISP upgraded my ADSL to version 2+ and now my router won't connect. I tried all the usual troubleshooting steps of rebooting and unplugging the ADSL wire to no avail. Next I got on the phone to my ISP, Demon. Demon ran line checks during which I was disconnected. Humph! Calling back I had to wait in the queue again. Try to be calm. Take deep breaths. Demon persuaded me to buy three new micro-filters which had no effect. Finally they told me that they would have to pass the call to a BT engineer. To top it all they asked me to pre-approve that I would pay £170 if BT found that the fault originated in my house. Naturally enough I declined their kind offer. Only thing now is to wait until Monday to see if they can fix it. Until then we're back to 1993 and dial-up internet.

Friday, 24 April 2009

E61 Mercurial Solution

Mercurial to version control files on my E61 phone. That would be sweet. I could edit text in PED then push and pull changes from my server using SSH. Only problem is that, as of writing, there is no mercurial client for the Symbian S60v3 operating system. Mercurial is a combination of Python and C code. In my dreams of spare-time nirvana I could attempt a port to S60, but realistically that isn't going to happen. I need a plan B.

Engineering Compromise

So, I'm not going to be able to have a command-line like experience of mercurial on my E61. What about the next best thing? My next idea was to use putty to: (1) ssh into a directory on my linux server (2) Update the mercurial repos there (3) Grab all the files from the linux server to the phone (4) Make edits on the phone (5) Upload the modified files back to the linux server (6) From putty on the linux server commit the changes into mercurial I've got this working. The tricky bit was to decide what to use to move the files about. I've ended up with MobyExplorer doing FTP to my local linux box. Inside the firewall I felt the FTP was safe enough. I'm a little nervous at opening up an FTP server on my public facing boxes. I had to set up secure FTP.

Secure FTP Set Up

I installed the Very Secure FTP Server (vsftpd) using aptitude. I made the following changes to the config in /etc/vsftpd/vsftpd.conf (1) local_enable=YES (2) write_enable=YES (3) anonymous_enable=NO (4) chroot_local_user=YES ...then restart the server with sudo /etc/init.d/vsftpd restart

Why does cygwin pick up 'f' as my home drive?

I installed cygwin on my new work laptop. For some reason when ever I ran cygwin it said:
mkdir: cannot create directory `/cygdrive/f': No such file or directory
Copying skeleton files.
These files are for the user to personalise
their cygwin experience.

These will never be overwritten.

/usr/bin/install: cannot create directory /cygdrive/f: No such file or directory

/usr/bin/install: cannot create directory /cygdrive/f: No such file or directory

/usr/bin/install: cannot create directory /cygdrive/f: No such file or directory

bash: cd: /cygdrive/f: No such file or directory
Your group name is currently "mkgroup_l_d". This indicates that not
all domain users and groups are listed in the /etc/passwd and
/etc/group files.
See the man pages for mkpasswd and mkgroup then, for example, run
mkpasswd -l -d > /etc/passwd
mkgroup  -l -d > /etc/group

This message is only displayed once (unless you recreate /etc/group)
and can be safely ignored.
cp: cannot create regular file `/cygdrive/f/group.mkgroup_l_d': No such file or
So, I must have got something set up incorrectly. Looking at the environment variables I see:
$ set
...lots of stuff
...more stuff
So where is HOME set? The work laptop is running Vista and I'm farily new to it. Looked in Control Panel >> System >> Advanced System Settings >> Environment Variables, but there was no reference to HOME. Next stop was Google, obviously. It told me to edit /etc/passwd. Sure enough there was a setting against my username for /cygdrive/f. I changed it to /cygdrive/c/dave and it all worked great.

Saturday, 28 March 2009

Video Editting Software

We were going to visit the National Media Museum, but due to son #2 getting a stomach bug on Saturday night that wasn't to be. Instead we made a video diary of the weekend. My camera records quicktime (.mov) files. I had about twenty of these to splice together by the end of the weekend. I didn't have a video editing program to use. A little wikipedia led me to avidemux. This seemed lightweight and just right for what I needed. To get a rough cut done to show the wife I just appended the files together. This worked fine, but after about three minutes the sound was a long way out of sync with the video. A quick scan of the avidemux wiki suggested I do Audio->Build VBR Time Map. I tried that but it didn't seem to do anything. Clicking somewhat at random, I don't know much about video, I tired Tools->Rebuild I & B Frames. That didn't help. I'm parking this one for now. See if inspiration strikes while doing the tidying up.

Sunday, 15 March 2009

Debian NSLU2 Stopped Working

My slug, NSLU2, stopped working. The power went off and it didn't come back on after booting. It just sat there with the ready light on yellow and the ethernet on green, but not showing anything on the disk 1 light. I couldn't ssh to it or ping it. Google led me to the NSLU2-linux-debian-readme page. This led me to suspect something wrong during booting. I turned off the slug and attached the USB drive to my debian PC. In the procees the entire USB hub stopped working. If I took the USB hard drive out the USB hub started working again. So I rebooted into windows, put the USB drive in and got an instant blue screen of death. Not good. Last attempt I plugged the LaCie USB drive into my laptop. The laptop didn't die, but windows said "Please insert disk" when I tried to browse to it. I'm thinking it is dead. Looks like I need to be buying a new USB hard drive and re-installing debian on the slug. If anyone has a better idea please leave a comment!