markwilson.it [formerly known as Mark's (we)Blog]

A few weeks back I was discussing backups with a couple of my colleagues. I’ve commented before that, despite nearly losing all of my digital photos and my entire iTunes library, I’m really bad at backing up my data (it’s spread across a load of PCs and I almost never have it in a consistent enough state to back up). I had thought that Windows Home Server would be my saviour, but Microsoft rejected my feedback requests for Mac and Linux client support so that won’t work for me. Besides which, I should really keep an offsite copy of the really important stuff. One of my colleagues suggested that I joined in a scheme he was setting up with remote transfers between friends (effectively a peer-to-peer network backup) but then another recommended Mozy.

Mozy? What’s that?

For those who haven’t heard of it (I hadn’t, but it does seem to be pretty well known), Mozy is an offline backup service from Berkeley Data Systems (who were purchased by EMC last week). Available as a free service with 2GB of storage (and an extra 256MB per referral - for both the referrer and the new customer - my referral code is L8FPFL if anyone would like to help out…), as a paid service with unlimited storage for $4.95 a month (per computer), or as a professional service for $3.95 a month (per computer) plus $0.50 per GB of storage, it seems there’s an option for everyone - although it is worth understanding the differences between Mozy Home and Mozy Pro.

With clients support for most Windows versions (including Vista) and Mac OS X (still in beta), data is protected by the Mozy client application using 448-bit Blowfish encryption (with a user-supplied key or one from Mozy) and then transferred to the Mozy servers over an HTTPS connection using 128-bit SSL. Upload speeds are not fast on my ADSL connection and there is some impact on performance but I can still use the web whilst I’m uploading in the background (in fact I have a a backup taking place as I’m writing this post). Also, once the first backup has taken place, Mozy only copies changed blocks so subsequent backups should be faster. The only problem that I found (with the Mac client - I haven’t tried on Windows yet) was that it uses Spotlight searches when presenting backup sets so if you have recently had a big clearout (as I did before backing up), the size of each backup set may be out of date (Apple support document 301562 offers some advice to force Spotlight to re-index a folder).

I should highlight that backup is only half the story - the Mozy client has a simple interface for browsing files and selecting those that need to be restored. There’s also a web interface with browsing based either on files or on backup sets and the Mozy FAQ suggests that Mozy can ship data for restoration using DVDs if required (for a fee).

Whilst Mozy has received almost universal acclaim, not everyone likes it. For me it’s perfect - an offline copy of my data but it doesn’t do versioning and it will assume that if I delete a file then after 30 days I won’t want it back. I think that’s fair enough - if I have a catastrophic failure I generally know about it and can restore the files within that month. As for versioning, why not have a local backup with whatever controls are considered necessary and use Mozy as the next tier in the backup model? The final criticism is about Mozy’s potential to access files - that’s purely down to the choice of key. Personally, I’m happy with the idea that they can (in theory) see the pictures of my kids and browse the music/videos in my library - and if I wasn’t, then I could always use my own private key to encrypt the data.

I’m pretty sure that I’ll be moving to the paid MozyHome product soon but I wanted to try things out using MozyFree. Based on what I’ve seen so far, using Mozy will be money well spent.