Able Mac

Time Machine is the "Defining Feature" of OS X Leopard (10.5). There were a lot of improvements in OS X, but Time Machine alone would have made it worth the cost of upgrading. It's brain dead simple. Plug in an external drive that's dedicated for Backups, and say yes when Leopard asks you if you want to use it for that.

But then there are those of us who don't want to have to plug in a hard Disk drive (HDD) to back up, let alone leave it plugged in to get the most out of Time Machine.

Many of us fully expected to be able to backup to the USB drive already attached to our AirPort Extreme Base Station (AEBS) and were surprised that we couldn't.

Then Apple released Time Capsule which is an AEBS with an HDD built in. Thank you Apple; but what about those of us who already have the hardware? Isn't Time Capsule proof that it can be done?

Well, Apple must not have been able to convince everyone to run out and buy a new AEBS with HDD built in, so they finally released a Firmware Update 7.3.1 for AEBS which adds the ability to use Time Machine with a Current AEBS (meaning with WiFi-N support).

There are a couple points to note.

1.) Time Machine still doesn't work if you've enabled user level access
2.) Hard Drive Level passwords are supported by Time Machine
3.) External HDDs can be replaced without sending in your AEBS for support

Our Test Setup is a 17" MBP running OS X 10.5.2 (9C7010), a Non-Gigabit AirPort Extreme Base Station in N (g/b compatible) mode with WPA/WPA2 enabled. And the HDD is a Seagate Free Agent Pro 750 Gig USB 2.0 & eSATA connected via USB to the AEBS.

I already had the HDD formated as HFS+ journaled for the Mac and already had a Time Machine Backup on it. Unfortunately, Time Machine won't use the existing backup on the HDD. It creates a single SparseBundle file to keep the new backup in. So if you have the Gigabit AEBS, you'd be way better off plugging in an Ethernet cord to create the first backup.

After the first backup, subsequent backups will only need to copy the files that have changed, so they can't run over the WiFi N fast enough unless you do video editing or some other task that changes several Gigs of data per day.

Some standard Time Machine Gotchas still apply, such as running Windows in Parallels, Fusion, Virtual Box, or any other Virtual Machine software, because it changes the HDD image file, which is usually 2 Gigs or more, and even a small change flags the file to be backed up again. You can exclude this kinds of files manually in the Time Machine Preference Panel of the System Preferences.

And for those of you wondering, the SparseBundle file wouldn't mount in OS X when I hooked the HDD back to the MBP directly via USB. It seems like it should mount like a SparseImage file would, but it doesn't. So my high hopes of just copying my existing backup into the SpareseBundle with my faster eSATA card were totally shattered. With 60 Gigs of data on my 200 Gig internal drive, Time Machine is copying at a rate that should finish about 18 hrs after I started the first backup.

And for those of you now wondering about my eSATA setup: Vantec dual port eSATA 3.0 Gbps. My real world performance is about 4 times faster than USB 2, about 3 times faster than FW400 (eSATA, FW400, and USB 2.0 on the same drive), and about 2 times faster than FW800 on an LaCie 600 Gig Big Disk (with 2 300Gig internal Drives for higher read/write performance). I didn't run testing software to rate the speed, and the speeds are based on copying large files (my Home Video library, and several iso files for Linux and other Discs).

AirPort Extreme