Your Data

Moving your TimeMachine


It's bound to happen to everyone, they outgrow their TimeMachine and want a new one, a bigger one, one that will allow them to go further into the past... I'm talking about OSX's built-in backup system here, I don't know what you were thinking..

So ever since starting to use OSX Leopard I've been using TimeMachine to keep a running backup of my laptop for two reasons - I can instantly jump back to an old revision of a file, and it keeps a near-constant mirror of the OS as it is with all of the software & settings intact. My laptop came with a 120gb drive and I've been using a 160gb USB drive for TimeMachine. Obviously enough, when this is my main machine I move a lot of files around - download lots of files (all legit), delete some, move others to a file server, but with TimeMachine keeping a regular hourly backup of all change files it can end up bloating up pretty quickly. Sure enough, within a few short months I'd filled up the drive and for the past three or four months it regularly informs me that it has flushed some older backups in preference to keeping newer data.

It's 2009 and hard drives of all sorts are insanely cheap. Taking advantage of the early sales I snagged a 320gb replacement internal drive for the laptop and a 500gb external drive for TimeMachine. Incidentally, both of the drives were made by Seagate, as all of my drives are, as all of their drives (at least up through their January 2009 new models) come with a five year warranty, so between backups I'm (mostly) guaranteed five years of usable storage.

Moving on.

I personally don't like moving data off a primary drive due to the inherent reliability problems of external storage - if it's important data then it needs to be on an actively used internal drive, not on a DVD or CD sitting on a shelf somewhere for grubby little fingers to play with (or get knocked over), and definitely not on a USB memory key that's going to get put through it's paces in the next laundry cycle. All external storage formats should be used for backups exclusively. End of story.

So, in order to keep my data intact I planned a drive shuffle. First I was going to migrate the TimeMachine backup data to the new external drive, then I was going to swap out the internal drives and follow up with a quick restore off the backup drive to the main OS drive. Simple enough, and something I've done before.

Well the first step, as mentioned, was to migrate the 160gb (actually only 145gb due to drive companies lying about the size of a "gigabyte") to the new 500gb drive so I could retain the last few months of data as an active backup. That seemed simple enough. Because the drive comes pre-formatted for use with Windows (NTFS), I plugged the new drive to my laptop, ran the funky Seagate software installer & allowed it to wipe & repartition my drive for OSX. After rebooting (yeah, go figure, silly company) I has a 465gb usable drive. But it didn't have my TimeMachine data.

The official guideline on migrating TimeMachine data is to use DiskUtility to "restore" the data to a new drive - odd terminology, but it kinda makes sense. Well, for some odd reason it started giving me an error when I tried this. Just to be sure (and because computers make us crazy by expecting different outcomes for repeating the same procedures) I tried again, and sure enough, the same error.


A quick google later and I find two shareware utilities that might also do the trick - CarbonCopyCloner and the amusingly titled SuperDuper. Long story short - both tools would run for a few minutes and then seem to get stuck, sitting with zero change in progress while saying they're copying this file that's actually rather tiny (so it wasn't that it was just moving a huge file). Enough of that, back to google.

A bit more research turned up an article on the excellent which detailed how to use the UNIX tool dd to copy a drive, including to use it to recover lost data off a partition. So I gave it a spin.

The instructions are simple. First off, use the tool "df" to find out the exact location of the partitions or drives you wish to copy (the first column marked "Filesystem"), e.g. the 160gb drive showed as "/dev/disk3" and its partition as "/dev/disk3s2", while the 500gb drive was "/dev/disk2". Then, once you know the drives you just run the following command: "dd olddrive newdrive" e.g. "dd /dev/disk3 /dev/disk2".

Well, while I was overjoyed that my first h@rDk0r3 use of UNIX in some time actually started to do something, I was dismayed to see it say the average copy speed was "1705KB" i.e. 1.7meg per second, and at that rate would take 26 hours to complete. Bummer. As it turns out, by default it works with tiny 512byte data blocks, which obviously takes FOREVER.

While researching it I come across another tool that bids itself as a simpler tool for migrating partitions called "ddrescue". I do a quick download, compile and run, and sure enough it's using the same block size. Sure enough, there's a handy little option called "--block-size", or just "-b" for short, that lets you tell it to use larger blocks of data at a time. A quick "-b 4096" later and the transfer speed jumped to ~5KB. Good enough, though it still took six hours.

After the six hours I now had a drive that seemed to all be there, but it only said it was 145gb and my efforts to resize it with Disk Utility just gave a wonderfully error that says "Error with partition: MediaKit reports partition (map) too small".

Back to the drawing board.

I then thought "maybe I have to copy just the partition instead of the entire drive. Six hours later... and I was left with basically the same thing - Disk Utility said that the entire drive was in one large 465gb partition, but Finder said it was only 145gb.

Back to the drawing board. Again.

And back to Disk Utility.

This time around I deleted the existing partition first so that the 500gb drive was completely blank. I then set the Rescue action to erase the destination. Four hours later it had copied all of the data, another two hours later and it had verified the data.

Golden. Or so I thought.

I now have a single, 465gb partition that shows up in Finder and Disk Utility. The only problem is that Disk Utility says that the drive itself has no partitions! While I'm stumped, I think I'm going to count my blessings, just deal with it - TimeMachine works again, and if I find a fix I'll post an update.

Why Trac sucks


Reasons to use Trac:

  • It has been around for ages so it's pretty well known.
  • It works with Subversion.
  • Built-in Wiki.
  • The milestones system works fairly well.

Why Trac sucks, IMHO of course:

  • It's written in Python, a language I currently don't know nor have a (current) inclination to learn.
  • It doesn't do git without a plugin.
  • How do I get email notifications when something's changed in the wiki?
  • How do I get email notifications when code changes are uploaded?
  • Each project you want to manage with it gets its own separate install, which is very klunky. You have to log into each one separately (unless you set up a shared authentication system of some sort in the web server).
  • Each project only gets one repository.
  • The interface is klunky, e.g. clicking View Tickets brings you to a page where you first have to choose your filter rather than just loading the last one used or a default.
  • No task associations so you can't do a parent-child dependency to indicate a completion hierarchy.
  • The interface should allow for trag-n-drop changing of priorities.
  • It isn't github or unfuddle or Redmine :)

Personally I recommend github for public projects where you don't need task management (I don't like Lighthouse), Unfuddle for closed projects or where you want good task management for your open project, or Redmine if you want full control and to host it all yourself.

Just thought I'd share that.

Mozy Backup - 2gb of online encrypted backup for free


I've mentioned Mozy Backup before, a service that gives you 2gb of free online backup space for your Windows or Mac computer. Well they've just released their "version 1.0" update for the Mac software so I think it's time to give it a go, you have nothing to loose. One minor note - I really wouldn't recommend trying the service if you only have a dialup internet service, it will take a long time to upload your data on a modem though once the first backup is finished additional ones should run pretty quickly for most people. Lastly, if you like it and need more than 2gb of space you can buy "unlimited" space for $5 per month per computer.

Beware Prolific PL3507-based Firewire enclosures


In the interests if keeping some data off my laptop's main drive but still accessible, I bought a Firewire/IEEE-1394 hard drive enclosure and stuck a 120gb drive in it. Well, tonight when I plugged it in the drive, after having it roaming the house for the day, the drive wasn't identified by OSX - the drive was on, I could hear it purring away, but it wasn't actually doing anything. As it turns out, the enclosure is controlled by the Prolific PL3507 chipset that has reliability problems, which sucks. Amusingly, the enclosure also has a USB connector, and when I plugged the drive in that way it worked! Go figure. So, time to get realistic with this and set up a Solaris & ZFS/RAIDZ-driven NAS, to heck with this silly single-drive, single point of failure BS, lets bring on some reliability for a change.

CardRaider - great little app for recovering lost photos


Recently the HD in my main Mac died. While I had just made a full backup, I had also moved some pictures off our digital camera into iPhoto, causing me to lose about 60 pictures. Well, thanks to how digital photography software work (they don't fully erase pictures off memory cards, just do a partial delete) I stood a chance to recover the pictures using one of the file recovery tools available.

After looking on MacUpdate for a suitable tool I settled on CardRaider, a $20 app that makes the process very easy: run the app, insert your memory card, click Scan and wait while it pours over the card looking for your lost media. As each photo is discovered it will be displayed as a thumbnail with some associated metadata, giving you enough information to decide which photos to recover. You decide which photos to recover and can either save them out to disk or import them straight into iPhoto - a little touch that goes a long way to boosting its simplicity.

The only issue I discovered was a slightly glaring problem that will hopefully be remedied soon: only photos can be recovered, the movie clips that almost all digital cameras can take are completely ignored, as are any other types of files. This greatly reduces its usefulness for me, and ultimately I'm going to have to find another app to recover the lost movie clips (we take a lot of them of our kids playing). I emailed the developers to ask when this feature would be added and was informed that while the feature was being considered for a future release nothing had been decided yet and so they could not give any guarantees.

If you are someone who only uses their digital camera for taking photos and not movie clips, this is $20 well spent that can probably save you much anxiety for those occasional accidents. If, on the other hand, you do take a lot of movie clips with your digital camera, you may want to look elsewhere.


Interestingly, I emailed the author my suggestion that it also be able to recover other files and at first he didn't seem too interested. Before I'd even finished this review, however, he sent me a test release of the next version that can recover AVI files (the format most cameras use). Talk about support! So, with this feature due to be added soon, I can't recommend this program enough! Well worth it!

And then I discover File Juicer which can recover images, movies and do a boatload more. Doh. C'est la vie.


Subscribe to Your Data