Backup basics, or, how to be usefully paranoid

My all-time favorite Bert and I routine (dry, New England Yankee humor) went something like this.  (Helps to read it with a Maine farmer accent in your head.)

Tourist: Would you say your neighbor is someone I could trust?

Farmer: Well.  (pause) I wouldn’t go so far as to call him a liar… but… if he wants his cows to come home from the pasture, he’s got to have someone else call them.

I take this slightly misanthropic (misantechnic?) approach to computer hardware.  A friend had a scary computer problem today, one that could have lost lots of data, so I thought I’d describe how I back stuff up.

Full backup system (pre-DOS)There are four parts plus the really nutty one:

  • Boring conceptual stuff hidden under the title “This is easy.”
  • What I do that you won’t think is nuts.
  • What I do that somebody, though perhaps not you, will definitely think is nuts
  • The nutty part
  • The really nutty part

This is easy

There are basically two kinds of backups, though probably hundreds of names for them.  That’s branding for you.

A full backup means making a copy of all the files in question — all of them in a folder, or in a bunch of folders, or on your entire computer.

An incremental backup means making a copy of any file that’s new, or any file that’s changed, since the last full backup.

Question:  on the typical day, do you update all the files on your computer?

(a) Of course, doesn’t everyone?
(b) No, of course not.
(c) How is this easy if there’s a quiz?

Backup software makes it easy to do both.  (If the software doesn’t make it easy, get different software.)

Making a full backup takes more time than making an incremental one, unless you chose A (in which case you don’t have time to read further).   That means that each day’s incremental backup takes much less time than you think.

What I do that you won’t think is nuts

I have an external hard drive connected to my computer.  My backup software lets me create a script in which I specify which folders to back up.  I organize my data into about six top-level folders (work stuff, personal stuff, blog backups, etc.), with lots of subordinate folders in them.

At the beginning of the month, I run a full backup.  There’s about 22 gigabytes of data involved, which means I don’t discard stuff much.  This takes about 2.5 hours, so it’s a good chore for just before lunch or sometime when I won’t be at the computer.

Each day, I run an incremental backup.  This examines all the folders in the full backup, and backs up anything that’s new or changed.  Typically that’s less than three minutes.

With that, all my data’s in two places: on the notebook and on the external drive.

What somebody might find nuts

I actually do this in three cycles.  I have a Month 1, Month2, and Month 3 script.  At the beginning of January, I run the Month 1 full backup, and then do incrementals through the month.

At the beginning of February, I run the Month 2 full backup, followed by four weeks of incrementals.  And in March, I run Month 3.

Finally, in April, I do a new Month 1 full backup.  This will overwrite the backup from January.

Why?  Because this means that at a minimum, I can retrieve the end-of-day version for any file, even if I’ve changed it daily, for the past 60 days.  I rarely need to do this, but it’s great to be able to.

The nutty part

My own Passport's a different shadeHere’s the thing: all those great backups are in the external drive on my desk, a foot to the left of the laptop.  That’s great if the laptop gets broken while I’m traveling; not so great if I have a fire, a flood, or a contractor breaking through the attic and dropping the ceiling onto my desk.

So I have another external hard drive–the small kind, about 3 x 5 inches (like the Western Digital Passport in the photo).  And on the first weekend of the month, my goal is to do another full backup (of my computer and my wife’s) onto this portable drive.

Which I then take to the bank and put in the safe deposit box—because it’s really unlikely the contractor will fall through the ceiling there, too.

Geeze, what could be nuttier?

I actually have two of those external drives, cleverly labeled Passport 1 and Passport 2.  This is because, after years of philosophy, I know that I’m not going to drive to the bank, get the hard drive, come home, do the backup, and go back to the bank.

Really, I’m not.

So, last weekend, after running the start-of-March backup onto Passport 2, I took it to the safe deposit box.  And I took Passport 1 out of the box and brought it home, so it’ll be here at the end of March.

Paranoid, yes, but (a) when I stick to this pattern my maximum data loss will be “the last 30 days,” and (b) think of the gas I save.

I could use an online backup service, but uploading all those gigabytes would be slower than continental drift.  This works for me.  As the mutual funds say, past performance is no guarantee of future return.

Determine your own risk tolerance.

CC licensed photos: early wireless backup system by Macloo;
WD Passport hard drive by CWOT.

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