Tag Archives: Backup

Why You Shouldn't Totally Trust Time Machine

Over the past month or so we’ve had a bit of bad luck with our unibody aluminium MacBook. About a month ago it was midway through backing up, and suddenly we started to hear a worrying crunching noise coming from the hard drive. We then got the spinning beachball of doom, and the machine became unresponsive. Rebooting produced nothing, the machine just wouldn’t boot. We managed to get a Genius Bar appointment for the same day at the Apple Store in Bath, and headed down to get the bad news that the hard drive was totally gone. The team in Bath replaced the drive and we picked it up a week later.

However whilst it was a pain, it wasn’t too much of a problem as our trusty Time Capsule had been quietly backing up using the built in Time Machine software. Having got the MacBook back all I had to do was hook it up to the Time Capsule, boot the machine off the OS installation DVD, select the restore option, point the machine at the relevant drive and a few hours later the machine is restored – well almost. Following advice from Parallels I had been excluding the virtual machines we had installed – whilst this speeds up the Time Machine backups, it’s a total pain when it comes to a full rebuild.

Anyway, we hadn’t lost any data, as that sits in shared folders on the Mac side – it just took the best part of a week to rebuild the virtual machine, in between Beth using the machine. I also made sure that the virtual machines were included in the backup just in case it happened again.

And happen again it did! Barely two weeks later, just I had finished the rebuild, the drive died again, and the machine went back to Bath. The team carefully checked over the machine and concluded that it was just bad luck, a manufacturing fault on the drive, no problem, it was replaced for free and I brought the machine home and did the same rebuild process.

All appeared well until today, when Beth decided she wanted to upload some pictures from iPhoto and tried to open the application. However the application came up with a dialog saying it couldn’t find her library. Looking around the drive, mine was intact, but Beth’s was nowhere to be found. No problem, check the backup – again, nowhere to be seen – however the backups only went back to the rebuild, nothing from before. All Beth’s pictures from the last year were lost!

A surf around came upon this discussion on the Apple Forums – the only use of the computer Beth had made between the two rebuilds had been uploading pictures in iPhoto, and whilst Time Machine would have picked up the iPhoto database eventually, in the short time between rebuilds the database had not been picked up at all, and the older copies had dropped off the backup drive due to the volume of changes that the virtual machine rebuilds had produced.

So the really, really, REALLY IMPORTANT point to take away from this is that Time Machine CANNOT BACK UP CERTAIN FILES IF THEY ARE OPEN, the iPhoto library being probably the most important item. Whilst over time changes will be picked up, if you spend most of your time in iPhoto, you’re obviously running a massive risk that you will lose your valuable pictures.

There are ways around it – firstly, make sure that you take regular backups with iPhoto closed. I’d also recommend not putting all your eggs in one basket, and having a parallel backup strategy, which is what I do on our iMac G5. Alongside the same Time Capsule and Time Machine combination I use the excellent Super Duper! from Shirt Pocket software. The two bits of software are complementary. Whilst Time Machine is great for picking up accidentally deleted files, it is a bit tedious for a full rebuild. Super Duper! creates bootable clones of drives, which if the worst happens and a drive dies, you can just boot the clone. I have had a drive fail on the iMac G5, and Super Duper! was my saviour – one cloned drive copied swiftly back. Indeed Shirt Pocket software themselves describe such a complementary solution on their blog. Whilst obviously they want to sell software, I’m happy to recommend the strategy as well.

Sadly, whilst many of Beth’s pictures were safely uploaded to Flickr or still on the camera, they weren’t all there. Equally all the keyword, faces and places classification she had done is lost, so it is definitely a case of learning the hard way that we need the same complementary backup solution on the MacBook that we’ve been operating on the iMac G5.

Finally, just in case you didn’t get it TIME MACHINE CANNOT BACK UP IPHOTO WHEN IT IS RUNNING!

Time Machine – Not Such a Foolproof Solution

Last night we had the kind of problem that most computer users dread, the un-bootable computer. Beth had used the iMac earlier in the day without any problems, but when I tried to start the machine up, it stalled during the start-up process.

The next stage when you’ve got any sort of Mac problem related to booting is to reach for the OS X install DVD, and use that to start up Disk Utility – more often than not this will sort out a lot of problems, however not in this case. Having run through the verification and repair process it came up with a big red message warning that it couldn’t repair the disk.

No problem, I’ve got a regular back-up strategy – periodically backing up to an external hard drive using SuperDuper alongside using Time Machine and an associated Time Capsule. The last full backup I did was about a week ago, just before the OS X 10.5.5 update installed, however Time Machine has been quite happily running since then, so I opted to have the OS X install rebuild the drive and reload the data from the Time Machine.

Then the installer showed me a list of the contents of the Time Machine – with the most recent complete backup being just before the 10.5.5 update, complete with a message saying that “Only complete backups of Mac OS X appear in the list”. On the basis that Time Capsule has been running normally, there should be newer files on there, but the implication is that it hasn’t managed to complete a backup since then – thinking back over our usage over the past week or so that might be right as we’ve had a lot of short sessions.

Like most users I guess, we largely ignore the operation of Time Machine. The icon sits on the title bar, and periodically the Time Capsule springs into life. However the software is deliberately designed to be non intrusive, and will quite happily cope if you want to shut the machine down whilst it is working – it just shuts itself down as the machine shuts down and restarts again the next time the machine is turned on, my assumption being that it will just pick up where it has left off. However even over a week of short sessions, it should have picked up all the files.

A bit of a browse around the internet for problems after the 10.5.5 upgrade turned up this – looks like there have been problems, plus also some comments about the number of files changed in the update. Time Machine has a two stage process, first it goes through a prepare stage, which is when it builds a list of the changed files, then after that it goes into the backup where the status message showing the progress through the backup. It could be that during our relatively short sessions this week it is never actually getting beyond the preparation stage.

At this point I was rather glad that I kept the two part backup strategy, so I booted up using the backed up image of the main drive and was able to copy off our respective mail archives, which in my case would be the most annoying thing to lose, and then set the machine going overnight copying the clone of the boot drive back across to the iMac. Taking a look this morning however, the restore had again stalled part way through, leaving the boot drive with errors – so the drive was cleared down again, and I’m again copying the SuperDuper clone. Even if it works though, I’m not massively confident in the drive in the machine, so I also headed over to Mac Upgrades to pick up a new internal drive – picking one that hopefully will allow us a bit more room to grow at 500Gb rather than the 160Gb that is in the machine at the moment. Apple also have a step by step guide to a DIY upgrade which seems pretty straightforward.

So any thoughts at this point? Firstly, I’m really glad to have SuperDuper around – the clone of the drive it produces coupled with the ability of the iMac to boot itself from the backup image is fantastic – if it wasn’t for that it would needed to have been either another Mac and FireWire target disk mode, or alternatively just losing the weeks worth of e-mail that hadn’t been backed up. The other important thought is to keep an eye on Time Machine and in particular when it has last done a complete backup – almost certainly explicitly forcing it to do a complete backup after significant operating system upgrades. The bottom line though is always make sure you have a good backup strategy – you never know when you might need it.

As to what caused it – it’s all a bit of a mystery. It could just be that the drive itself has given up – the machine is a few years old now and gets pretty heavy use. The other odd thing is that looking at the multi-way adapter into which the machine is plugged in, the light indicating that the surge protection is working is no longer illuminated. I could confirm one way or the other if I had the OS X logs, but they are of course on the failed drive, so I guess we’ll never know…