Think Twice Before Deleting Stuff (Or Better Not at All!)

No, this is not going to be another "Remember to do snapshots" post. I'm also not going to talk about backups. Instead, let's look at some very practical aspects of deleting files.

So, why delete a file? "Trivial", you think, "so I can save space!". Sure, dear reader, but at the expense of what?

Let's stop and think for a minute. Our lives try to center around doing cool, worthwhile, meaningful, useful stuff. Deleting files isn't really cool, nor fun, it is a necessity we're forced to do. Don't you hate it when that dreaded "Your startup disk is almost full" message appears while you're in the middle of downloading new photos from your latest exciting vacation trip?

Actually, the seemingly simple act of deleting is really a challenge: "Will I need this again?", "Wouldn't it be better to archive this instead?", "Last time I was really glad I kept that email from 2 years ago, so why delete this one?". Sometimes I surprise myself thinking a long time before I really press that "ok" button or hit "Enter" after the "rm".

To put things in perspective, let's try an ROI analysis of deleting files. Let's say we need about 6 seconds of thinking time before we can decide whether a particular file can really be deleted without regret. Let's also assign some value to our time, say $12 per hour (I hope you're getting paid much more than that, but this is just to keep the numbers simple).

Storage is cheap, and last time I checked, a 1 TB USB hard drive cost about $100 at a major electronics retailer, with prices falling by the hour.

Now, how much space does the act of deleting a file need to free up so it justifies the effort of deciding whether to delete or keep it?

Well, our $12 per hour conveniently breaks down to $0.20 per minute, which allows us to perform 10 delete-it-or-not decisions per minute at $0.02 each. Fine. Deleting seems to be cheap, doesn't it?

Now, for that $0.02 you can buy a 1/5000th of a 1 TB hard drive. Wait a minute, 1TB/5000 still amounts to 200 MB of data per $0.02! That's more than you need to store a 10 minute video, or a full CD of music, compressed at high quality! Or 20 presentations at 10MB each! Not to mention countless emails, source code and other files!

So, unless the file you're pondering is bigger than 200MB, it's not really worth even considering to delete it. I'll call this 200MB boundary the "Destructive Utility Heuristic (DUH)".

The result is therefore: Save your time, buy more harddisk space (or upgrade your old hard drive to a bigger one before it dies) and move on. Life's too precious to waste it on deleting stuff. Create good stuff instead! Only think about deleting stuff if the file in question is bigger than 200MB.

See, once you think of it, there's not really a need to delete files at all any more. At least not for mere mortals like us with file sizes that are typically below the destructive utility heuristic of currently 200MB (and rising...) most of the time. Music has already reached the point where a song can be stored at studio quality with lossless compression at manageable file sizes so that kind of data won't see significant growth any more. And photos and videos will soon follow. This means we'll need to care less and less about restricting personal data storage. Instead, we now need to focus more on managing personal storage.

Now there's a completely different problem that'll keep us entertained for some time...

Comments:

This post is one of the worst in the history of the internet.

Just because solaris has a good file system does NOT mean that the logical next step is to fill it with crap.

The env and dollar costs of what you are proposing are unfathomable if adopted widely.

Thankfully its such a crap idea that it won't be

Posted by nony mouse on March 27, 2009 at 03:38 AM CET #

Hi Nony,

thank you for reading my blog and for commenting.

Please note that I'm proposing a threshold beyond which it _does_ make sense to delete data. Clearly, deleting data in the ranges of hundreds of MB still makes sense.

I'm just saying that data which is in the range of only a few MB is just noise where the cost of deciding on its fate is bigger than the benefit of deleting it.

The interesting thing here is how large the file size has become, beyond which deleting doesn't really buy you much. It's now in the range of the typical YouTube video, for instance.

If you can find a way of efficiently identifying the "crap" so it can be deleted in bulk at a small cost in terms of user attention, then I'm all for it.

Thanks,
Constantin

Posted by Constantin Gonzalez on March 27, 2009 at 09:02 AM CET #

Good Point, Constantin.

Posted by Sebastian on April 01, 2009 at 01:42 PM CEST #