Let me tell you a somewhat long tale about the week I’ve had. This will get a little geeky, but you’d find out exactly why you should be using Time Machine and maybe a few tips to help your disaster recovery process.
Time Machine is Mac OS X 10.5’s automatic backup system. You attach a drive to the computer and after a simple dialog, you’re backed up.
Time Machine backs up every hour, quite quickly, and then keeps the last day’s changes and one set of changes every week.
If your computer has a 140gb hard drive and you have a 300gb Time Machine, you can easily keep 3-4 months worth of data in your Time Machine. This allows you to go “back in time” and get a file you just ruined, etc.
I have three Time Machines:
- One I keep offsite, that I plug in once a week or so to update. This is in case the house burns down
- One I keep downstairs in the office
- One I keep next to the couch
To switch Time Machines, you simply attach the drive, open the Time Machine preferences and select the different Time Machine.
Last Tuesday I had been on the couch using Time Machine as normal, then we went to lunch. As I usually do, I unplugged the Time Machine to take it with me, so that way, again if the house burns down, the laptop is lost, but not my data. Call it paranoid, but I did have a tree fall on my house once
We come back from lunch and get back to work. Later that night, around 7pm I am checking out World of Warcraft and noticing i have very slow graphics, like 8-9 frames per second.
Being a developer, I download the 10.5.2 graphics update 1.0 and reapply this to my Mac, thinking it couldn’t hurt.
Well, on reboot, my video was dead. Black screen of death. Over the next couple hours I tried everything, reset the SMC, the PRAM, try an external monitor, boot off DVD, boot off the repair disk, safe boot, you name it, I tried it.
Well this sucks. We are shipping Sophie this week and my machine is dead.
I have a second laptop, which Elizabeth uses, so I decide to use that. Now both of these machines have user accounts for me and both have the same ’short’ name. This proved to be very important.
I log into my user on the backup machine and attach my Time Machine. Then I use Browse Other Time Machines by holding down option when I choose the Time Machine menu in 10.5.2. I select my Time Machine drive and wham, there are my files!
So I go back in time, and the last backup is from 1:57pm, when we went to lunch. Crap! I had not plugged the time machine in again.
Since I knew the laptop was working, I removed the Time Machine from the backup machine, booted the now-video-less laptop, attached the Time Machine and waited. Then I logged in by typing blindly.
I then waited and waited until I saw the disk being used and yes, Time Machine was backing up. This took an hour, but you can start it by ssh if you are a geek - Another article on that topic later.
So after the Time Machine disk stopped accessing, I pressed power, then return to safely shut down. I plugged the Time Machine back into the backup laptop and wham, the most recent backup was now the current time.
I restored my email and work data and went back to work.
I took the laptop into the Apple store at 8:30pm and they said they didn’t have the motherboard. I called the next morning and Bridgeport Village had one. By 12pm Wednesday Apple had my machine and I headed home to get back to work.
This morning, Thursday at 8:30am I get a call. My laptop is repaired! Sweeet! So I go pick it up at 10am and notice they forgot to reset the serial number. This was a sure sign I did indeed get a whole new motherboard. They reset the motherboard and I come home. Talk about great service!
I use the time machine on the backup laptop (A different time machine disk) to restore the data I had worked on from the previous day and a half, remove the second time machine and plug in my downstairs time machine.
I didn’t want to touch my most recent time machine, and did this prove to be wise.
You see, my machine name is ’serenity’ and while I had a new motherboard, I had the same hard drive. So, I should just plug in the Time Machine, select Backup Now and be good to go, right?
Nope. “Not enough space to back up, please choose another Time Machine”
What? Alright fine. I look on the Time Machine disk and there are now two folders, ’serenity’ and ’serenity 2′ Oh noes, Time Machine thinks this is a new computer
Sure enough, with help from friends I found this article on Mac OS X Hints that describes how Time Machine records the Ethernet MAC address of your computer with the folder associated with your machine.
This data is kept at a very geeky layer, hidden in the Access Control Lists, so repairing this was not for the faint of heart. That is another article topic for later as well.
After a lot of mucking around, and an all important reboot, I had my time machine understanding that this new machine is really the computer for this time machine.
I’ll have to repeat these steps with my other two time machines. Joy.
So, after all of this, what did I learn that I can pass on to you?
- Keep your Time Machine plugged in 100% of the time, so you always have your latest data
- Do not use an internal disk for a Time Machine. Convenient? Yes. Easily usable on an emergency computer? No.
- Keep file sharing turned on just in case your computer’s video dies.
- Spend the money and buy multiple drives for Time Machines.
- Be aware that if a computer repair replaces your motherboard, you likely won’t be able to use your old time machines for backing up. You can get the data off, but likely not put more data on, depending on the size of the drive.
I can see why Apple doesn’t just use a machine name to map computers to Time Machines. There are many scenarios where someone could wipe out a Time Machine by either naming their machines the same, or getting a new computer and wiping the time machine out by backing up an empty drive, etc.
However, Apple does need to handle this use case where nothing but the motherboard changed.
Regardless, use Time Machine. Use many Time Machines. Keep them running 24/7.
It will save your butt when Murphy’s Law strikes.