a 45 MB hard disc, the first one I owned
(now sadly deceased, but backed up first)
I mentioned a backup device in passing in my technology post last month, but I wanted to have a more detailed discussion about my philosophy on this aspect of living with technology.
The Value of Backups
As the noted technology blogger Daniel Rutter says, data you haven’t backed up is data you do not want.
And in these modern times, everything is data: photos, documents, books, video, music… if it’s represented or manipulated by a computer, it is data and if you care about it then you should back it up.
I always try to be sympathetic when I hear tales of lost data – I have a few of them myself – but fundamentally, if you don’t back it up you really should not be surprised when some of it disappears into the æther.
Multiple Backups In Multiple Places
What is a backup?
A backup is a copy of the state of your data at some known point in time.
So, whenever you save a copy of your document with a different name, or copy your photos onto another spot on the disc, then you are taking a backup.
However, a backup is only really useful if it is available when catastrophe strikes. If the only backups you are taking are on the same hard disc as the original data, then the backups won’t be available when that same hard disc goes to the Great Spindle in the sky.
You mitigate this risk in two orthogonal ways:
- copy the data onto multiple forms of media
- put the copies in different places
Doing these two things will maximise your chances of being able to recover the data when you need to.
Automate It Or It Doesn’t Happen
Any backup process which relies on a human typing a command or pressing a button to trigger the backup will inevitably fail.
In other words, if there’s no automatic backup then there is effectively no backup at all.
Trust But Verify
Do the backups you are making actually work? That is, can the data you have saved on these multiple forms of media be read back?
I’ve been bitten by the assumption that they could. I had a fault in the motherboard of my PC which prevented it from calculating checksums accurately. I knew that fixing it would require at least an attempt to format the hard disc and reinstall the operating system, and so I backed up all of my data onto zip archives which spanned multiple floppy discs*.
… except that all the zip archives were corrupt, because the PC couldn’t calculate checksums.
That was not a good day.
Anyway, it is a phenomenally good idea to occasionally check that your backups are real rather than notional.
What I Do
There are basically two classes of data which we care about backing up:
- laptop state – what the individual machines have on them which we would need to restore if they suffered a hardware failure.
- shared data – irreplaceable files, particularly family photos and the like.
So, with those points in mind, here are the levels of backup which we have:
- Time Machine – we are, for reasons explained in the technology post, a Mac household and so it is a trivial matter to set up backups to a Time Capsule device using Time Machine. Once you have that backup, you can use it to restore your computer to its original state***.
- external HDs – we have a pair of external hard discs which I alternate between to perform manual backups on all user machines. As noted above this is not a reliable process because it is human-driven, but this is the form of backup which is stored in the fire safe (and which is therefore safe from network intrusion too).
One friend of mine also puts the unused external HD into a safety deposit box at the bank, which seems like a pretty sensible thing to do.
- shared network storage – the Time Capsule can act as shared network storage, but I prefer to use another device so as to avoid overworking the storage drives in the Time Capsule. Also, the Time Capsule does not apply any redundancy to its storage.
Hence we have a Synology Diskstation with two matched drives in it which are configured in a redundant array. This is where we put common data, since there is some chance that we would still be able to access it even if one of the RAID discs died.
- shared storage backup – there are a number of network storage devices out there, but the reason I picked the Synology one is that you can attach an external disc to it and have the data backed up occasionally to that external storage.
I’m pretty happy with this backup system, inasmuch as there are multiple copies of everything in multiple forms. The only thing I would wish to add would be some kind of cloud backup.
In addition to the primary backups, I also backup my writing.
Firstly, active projects are stored on Dropbox so that I can share the manuscript between those machines that I use – in point of fact, the sharing is in fact the reason I do this but having a cloud-based backup does not hurt. And of course this is regularly verified by my using the project on the other machine.
Secondly, at the end of any writing session, I will archive my Scrivener project and email it to me GMail account. Again, this serves as a cloud backup.
Finally, a lot of my notes are in Evernote – not exactly backed up under my control, but at least in the cloud and therefore supposedly backed up by the company****.
So, that’s what I do – do you have a backup strategy? How redundant is it? And do you have any terrible lost data stories?
[*] the 3.5″ kind, which were neither floppy nor circular**.
[**] yes, yes, I know – the medium inside was a flexible plastic disc.
[***] my only hesitation with this is that I do not know how to test this backup without another Mac to overwrite.
[****] now I come to think about it, I need to revisit this.