Top Time Machine Tip

Here's a Top Tip for those using Apple's Time Machine...

If you are backing up multiple computers to a single Time Capsule, and one of the machines decides there isn't enough space to complete a backup, try compacting the other backups - especially if they are quite large.

Open a Terminal and the following command:

# hdiutil compact /path/to/backup/sparse/bundle

I did this on the backup of my machine, when another laptop was deleting old backups trying to make space, and it freed up over 90GB of space. Plenty enough to allow the other machine to complete it's backup.


I turned off automatic backups while it was running - remember to re-enable them afterwards.

This is something that Time Machine will run itself if it's runs out of space, but it will only compact the backup for the machine that it is running on, so if there is a potentially large amount of free space in a backup for a different machine that won't get reclaimed. Instead the first machine will start sacrificing it's older backups to make space.

Note: I'm running Time Machine on OS X 10.6.6

These Boots Are Made For Walking

How long should a pair of walking boots last?

Berghaus - worn out after 6 months.

In March 2010 I bought a pair of Berghaus Explorer Trek lightweight boots, and was a bit disappointed when the soles wore out after only six months of use. However, thinking about it in a bit more depth - six months is 26 weeks, I probably walk around 20 miles a week with the dog, and so the boots could easily have gone for 500 miles or more before the soles wore out - at a cost of around 17p/mile (interestingly a similar amount to what petrol costs are for the car).

This compares fairly favourably with my "proper" walking boots (Meindl Burma Pro), which have, by my reckoning, covered around 650 miles in the last 7 years (albeit quite tough miles in some cases). But given they cost almost twice as much as the lightweight boots they are currently coming in at around 25p/mile - although they are still serviceable, so I expect them to clock up a few more miles. But it is sobering to think that they will have to do almost 300 more miles to reach an equivalent economy to the lightweight boots.

Zamberlan Trek Lites - 480 miles.

My previous walking boots (db Mountain Guides) covered around 660 miles, to come in at 18p/mile (although they had been replaced early in their life, when the eyelets in the original boots failed). Eventually they became too uncomfortable to wear, rather than actually failing.

Before that I had a pair of Zamberlan Trek Lites, which although they only managed 480 miles before one of the soles started coming off, also came in at around 19p/mile.

Hawkins Kestrel - 5p/mile.

But all of these have some way to go in order to beat my first pair of boots - a pair of Hawkins Kestrel boots, bought for £23.50 in 1986. They managed 550 miles (including the Wolds Way, the Coast to Coast and the 10 Highest Peaks in Britain, along with many other walks) before one of the heels finally fell off while backpacking on Beinn Challum, clocking in at under 5p/mile.

So looking back, it seems that 500-600 miles is about par for the course for a pair of walking boots, and just because I covered that distance in several months rather than several years I shouldn't feel that the Berghaus boots have underperformed.