Goodbye Time Capsule, Hello Trouble?

After several more days spent [[:node/134|trying to get my Time Capsule working properly]], I finally returned it to the Apple Store and bought an external hard drive and an Airport Extreme to take its place. The price for the two items together was almost the same as the price of the Time Capsule by itself -- only $40 more. It took a few hours to get them set up, but everything is going smoothly now -- at least for the time being.

I've learned a few things in the process about the technical issues and techniques needed to perform wireless backups using Time Machine. I'll focus here on those technical issues and save the rant about buggy technology for later.

On the technical side, there are two issues that I ran into:

  1. Time Machine uses the [[w:MAC address]] of a computer's logic board as part of its way of identifying the computer to which backups belong. Most of my latest round of problems began when the logic board went bad on my laptop and had to be replaced. This changed the MAC address and meant that Time Machine on my laptop could no longer find the backups.
  2. The filesystem for networked hard drives (which connect to the computer via [[w:Ethernet]] cable or [[w:Wi-Fi]]) is different than the file system for hard drives that are cabled directly to a computer via [[w:Firewire]] or [[w:USB]]. Time Machine's method of backing up to networked hard drives like Time Capsule is therefore different than its method of backup up to hard drives that are connected directly. This is probably why Apple didn't include a Firewire or USB option in the Time Capsule. Firewire and USB are markedly faster than Ethernet or Wi-Fi, but since Time Machine's backup method is different for networked vs. directly-connected drives, you can't simply switch from one to the other and have Time Machine still recognize the drive.

For both of these issues, there are workarounds:

The MAC address issue

This can be addressed by using the Terminal to rename some files and change some settings. Sean Kelly has written the best explanation I've seen of this problem and how to fix it:

Other discussions of the problem and solutions can be found at the following URLs:

The link is mostly an elaboration on the instructions at I haven't actually tried following the instructions, so I can't vouch personally for whether they work, but someone might find them helpful.

The filesystem issue

This can be addressed through a procedure that James Shore has written, which basically tricks Time Machine into treating hard drives as though they are on a network, even when they are connected via Firewire or USB:

The following links may also be helpful in dealing with the filesystem issue:

The threads at suggest that there may be problems down the road for people who use Time Machine to back up onto an external hard drive using Airport Extreme (which Apple [ doesn't officially support]). Apparently the operating system upgrade to OS 10.5.6 broke something that had to be fixed by reconfiguring a system preference. I wouldn't be surprised if future upgrades break it again.

For people who have to deal with this, there are some terms and clarifications to bear in mind:

  • Time Machine is not the same as Time Capsule. I've seen several people confuse the two inadvertently in support forums and message threads. Time Machine is software built into the Mac operating system, beginning with OS 10.5, for the purpose of automatically backing up the computer to an external hard drive. Time Capsule is a piece of hardware consisting of an Airport Extreme router with a built-in hard drive. It is marketed as an easy backup device that works with Time Machine so you can back up your computer wirelessly using Wi-Fi. In practice, I've had a lot of problems getting it to work properly.
  • Airport Extreme is not the same as Airport Express. Here, too, I've seen some confusion in discussion forums. (I think Apple is contributing to the confusion by giving them such similar names.) Airport Extreme and Airport Express are both Wi-Fi routers made by Apple, but they have different features. Both routers will distribute a internet connection wirelessly, and both routers will let you connect wirelessly to a USB printer, but only Airport Extreme lets you connect wirelessly to an external hard drive. (As I stated previously, Time Capsule is basically Airport Extreme with a hard drive already included.) The ever-helpful Wikipedia has [[w:Airport|an article]] explaining the different Airport models and how their features differ.

It also helps to understand the differences between networked hard drives and drives connected directly via USB or Firewire. has an article that [… explains the differences] in some detail. Here's the most important part:

When using a directly connected drive, Time Machine saves its backup files in a hierarchy of folders by date. Part of the magic of Time Machine comes from the use of hard linked files, where a single data file on disk can be linked to multiple file records appearing in different folders. This enables the system to keep a full set of files for each backup session without actually duplicating the contents of the files that haven't changed. This also allows Time Machine to delete folders of backed up files that are no longer needed without coping any of the files around, yet maintain a full set of backups. Hard links were described in greater detail in the article Road to Mac OS X Leopard: Time Machine.

Apple added support for hard links to the Mac's native HFS+ file system to support Time Machine. Some file systems don't support hard links, so in order to consistently handle Time Machine backups on network shared file systems, Time Machine uses a different method of saving its files: it creates a sparse file disk image that appears to the native file system to be a standard file, but which Time Machine can internally organize as a virtual HFS+ disk with support for hard links. Inside this disk image, the hierarchy of hard linked files looks the same as that of a directly connected Time Machine disk.

Got that? Let's repeat: If you're connected directly using USB or Firewire, Time Machine just puts the backup files on the drive. If you're connected via a network using Ethernet or Wi-Fi, it creates a "sparse file disk image" (actually, a [[w:Sparse image|sparse bundle]]). A sparse bundle is a file (whose filename ends with the extension ".sparsebundle") that can be mounted so your computer treats it as though it were a separate disk drive, similar to the [[w:Apple Disk Image]] (.img) files that are commonly used to distribute software. To mount a sparse bundle, double-click on the .sparsebundle file.

The procedure by James Shore that I listed above tricks Time Machine into creating a .sparsebundle file even on hard drives that are connected via USB or Firewire. This is helpful because in practice, wireless backups via Wi-Fi are S-L-O-W. Networked backups using Ethernet are a little faster than Wi-Fi, but doing it this way, which i what Apple recommends on Time Capsule, is still pretty damn slow. The slow data transfer rate is tolerable if you're not copying a huge amount of data, but when you create your initial backup in Time Machine, the process is maddening. The first time I tried doing an initial backup on Time Capsule, I unwittingly used Wi-Fi, and my computer ground away for several days without completing. During my recent troubles, I did another initial backup via Ethernet that copied about 130 gigabytes in about 12 hours. That's still a long time to wait, especially if it's part of a troubleshooting process which may require multiple attempts. By comparison, I was able to accomplish the same initial backup of 130 gigabytes using Shore's procedure in just under 4 hours.

Back to the future

The reason I bought a Time Capsule to begin with was that I really like the idea of automatic, wireless network backups. The biggest problem I've seen with backup systems is that people don't remember to do them. A system that does it automatically, where people don't even have to remember to plug in a cable, would fix that problem if it worked properly. I think the idea of wireless, automatic backups is a very good one and has a bright future.

The problem with Time Capsule, however, is that it forces people to settle for slow data transfer speeds, even when moving large amounts of data. The only way you can connect to the hard drive in a Time Capsule is via Wi-Fi or Ethernet, which not only makes initial backups go slowly but also limits its usefulness if you want to copy other files to and from the device. (Suppose, for example, that I wanted to make a copy of my .sparsebundle file onto another computer, or use Time Capsule for a purpose other than backup.)

Shore's solution makes it possible to have the best of both worlds -- a fast connection when doing the initial backup or when doing other operations that require speed, with the option of switching to wireless for routine incremental backups. I should note, however, that even Shore says he has "stopped using the network-based Time Machine entirely because it was too slow over my wireless network, even with the accelerated initial backup. ... I still have a Mac, and I still have Time Machine, I've just stopped doing network backups. I have my Time Machine disk plugged into my Macbook's USB port."

We'll see how it goes in my case. Shore's Airport Extreme solution seems like my best option at present. If that proves unworkable, I'll give up on wireless and go back to what I was doing before I bought the Time Capsule. At least my current hardware gives me that option, whereas Time Capsule doesn't.

I'm not the only person to reach the conclusion that Time Capsule is too slow. When I [ posted the problems I was having] with Time Capsule on Apple's support forum, I was promptly chastised by a retired gentleman (username Smokerz) who apparently has so much time on his hands that he actually enjoys the "learning curve" of scouring support sites for guidance on how to get his backups working. Even he admitted, though, that "[ I don't really use TC for Time Machine backups], its too slow."

Time Capsule has also drawn [… complaints similar to mine on the Tips4Mac blog]. Here are a couple of examples:

  • "This sounds MUCH better than it actually works. Lots of problems can happen with corrupt backups/Power outages/internet ups and downs and frozen computers needing a hard shutdown/restart. I have my TC connected ethernet and I can not even get one complete backup. I have a 300$ Airport Station.It also has been a huge waste of my time as I have tried to get the Backup to work with nothing getting in it's way. It fails every time. The most unApple product and experience I have had yet!"
  • "I have been using Time Capsule for a couple of weeks now, and so far it has been a pretty frustrating experience. Even after the recent Airport/TC update, it is still a pain quite often. I have had a few backups work, but probably at least half of them don't work. Often times it will say 'Preparing Backup' for over an hour. Then other times the TC will just keep resetting my connection for no apparent reason. I plan to call Apple this week to see if they can sort it out - if not, I'll probably return the Time Capsule and stick with wired backups."

And here's another thread in Apple's support forum where people complain of [ all sorts of problems].

Time Capsule is a good idea in theory, but thus far the implementation is so flawed that I think it is being sold under false pretenses. Its product page on advertises it as "Automatic wireless backup for your Mac. ... Time Capsule is a revolutionary backup device that works wirelessly with Time Machine in Mac OS X Leopard. It automatically backs up everything, so you no longer have to worry about losing your digital life."

"No longer have to worry"? For me, Time Capsule created far more worries than it eliminated.


Stumbled upon your blog while looking for something else. Just wanted to make a quick comment: The ethernet connection on the Time Capsule is lightning fast. One gigabit. This is faster than firewire 800, and certainly faster than USB 2. It may be that your computer is outfitted with a very old ethernet port, 10 Mbit or 100 Mbit, in which case transfer rates would be considerably slower than USB or firewire. But for anyone with a newer computer, your workaround is much more trouble than it is worth.

My computer is pretty new -- a 2008 MacBook Pro with a 2.4 GHz Intel Core 2 Duo processor. I took my problem in to the Genius Bar at my local Apple store, and they spent the better part of a day trying to get it to do a single initial backup. I dropped it off in the morning and came back shortly before closing time, and they figured that at the rate it was going, it would probably take another couple of days to complete. If that's the result they're getting, that tells me it's not just something I'm doing wrong, and they never indicated either that there might be something unusually slow about my ethernet connection.


It is slow. The back ups are slow, the booting up is slow. The only thing that was fast about it was the speed my credit card was approve for the purchase. was never marketed as being "fast". It was marketed as being, er convenient. And it is. Why, I just let me mac and TC work it out on their own.
You wanna know whats slower? Try attaching an external hardrive to the TC and try to transfer data to it. Now that's slow. Its been 8 hours since I started to transfer 8gig of data to my 1 TB Maxtor hard drive.
Anyway, I really should have read your entry on the slowness of the TC. I would not say I would not buy the TC anyways but now that I did, I concur with all you said about it being slow.

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