Time Capsule

18 months ago, I bought an Infrant ReadyNAS to store MP3s and our home backups. It’s been all peaches, and we’ve been using SuperDuper for backup against it with no issues.

When Leopard came out, thought we’d switch to Time Machine for backup… only to discover that Time Machine doesn’t support backups to network shares — unless those shares are on Mac (HFS+) volumes. The ReadyNAS does do AFP, but the ReadyNAS itself is Linux-based, and its internal filesystem is ext-something.

This sucks. Without simple, any-OS network backups, you’re forced to attach a physical disk to each machine you want to back up — unless you’ve got OS X Server running somewhere in the house (and thus have some networked HFS+ volumes to back up to).

Found a hack on the Infrant forums to force Time Machine to see a ReadyNAS share as a supported volume:

sudo defaults write \
TMShowUnsupportedNetworkVolumes 1

Timecapsule It works! Time Machine has been backing up to a partition on the ReadyNAS for a few weeks now. But I haven’t had occassion to try and restore from it yet, and don’t completely trust it. Apple’s introduction of Time Capsule seems like the perfect answer, and is dirt cheap for what you get (remember it doubles as an AirPort base station and print server).

But I resent that it’s required. Daring Fireball has essentially the same gripe. I already have an excellent networked storage unit. I shouldn’t have to buy Apple hardware to accomplish this. Apple needs to step forward and support TM backups to any network volume. Time Machine shouldn’t be a gateway drug sucking you into the Apple Store.

Of course, no law prevents me from continuing to use SuperDuper. But TM feels so good…

Music: Alton and the Flames :: Tuff

14 thoughts on “Time Capsule

  1. I strongly suspect that it is disabled for a reason. The network backups inherently must work different from the standard time machine backups, since TM uses hard links (as opposed to symlinks) in the FS to accomplish it’s backups… This is how when you look at a collection of TM backup directories it looks like the entire file system is backed up in each directory. The blocks for each (revision of a) file are only on the disk once, but they use hard links to refer to them multiple times from each backup directory.

    Apple actually changed a decades-old Unix paradigm, allowing for hard linking directories. This was always disallowed because it can create some nasty circular references, but Apple realized that they were able to use it for good and probably prevent mis-use in the Kernel.

    Anyway, several network file systems have no support for hard links, and several disk file systems have no concept of hard links (ntfs, for example).

    So my guess is that they either use their own network file system and HFS+ on the network volume, or they have come up with a separate mechanism for backup. In the former, network volumes would need to support HFS+ or this special network FS. In the latter, they would need to test the hell out of it, and would likely encounter all kinds of edge case nightmares that were different from the edge cases they encountered when testing the local TM backups.

    I have no idea how they solved this problem, but my guess is that in the near future you’ll see drives connected via Airport Extreme APs supported, but I doubt you’ll official support from Apple for other shares for the same reason you don’t see them supporting OSX on non-Apple hardware; support….

  2. What disturbs me the most about Time Capsule is that it basically discourages people from having an **offsite** backup.

    What do you do when your house burns down?

  3. PJ-

    I think you might be living in a dream world. Forget about offsite backups, most people don’t back up at ALL! Time Machine and now Time Capsule are attempting to address the huge majority of people who have terrible backup practices.

    In an ideal world people would have great regular local backups combined with off-site backups, but very few people do… I back up some important data to Amazon S3, but for the most part my real backups never leave my house. And I’m perfectly fine with that. I’ve had 10 hard disks die on me over the past 20 years, but I haven’t had a single house fire.

  4. Since the new Time Capsule is backing up via the network, I can’t imagine the hooks from TM have a problem using the network. Drobo just released it’s NAS front end (DroboShare) and their forums/beta users have successfully been using Drobo (as NAS) to backup with Time Machine. SO – I think it’s just Big Brother at Apple, no real technical reason.

    Also – this does discourage offsite – everyone should have copies of their most important data in case of disaster, just makes good sense.

  5. Sean, my understanding was that early Leopard betas did support backup to various non-Apple network shares, but that support was pulled before Leopard was released. This could have been either technical (for the reasons you give) or strategic (to encourage purchase of Time Capsules).

    On the flip side, it would be cool if TM could be enhanced to work with disk images, like SuperDuper does. At backup time, reach out and find the .dmg, mount it, sync into it, unmount. Or heck, leave it mounted all the time. Then you could easily have an HFS+ volume living anywhere. Not sure what the impact on efficiency is, but even if it’s a bit slower, it’s a price many of us would be happy to pay (unless grossly inefficient).

  6. You guys keep saying this discourages offsite backup, how does it?

    Obviously Capsule backups don’t prevent people from making a 2nd backup to S3 or whatever, but very few users are going to run two parallel backup systems at once. Once they adopt one solution, that’s almost certainly the only one they’ll use.

    On the other hand, it’s very unlikely that a normal user choosing a backup system is going to choose an off-site system, whether it’s Apple provided or not. Normal people just don’t think that way.

    Remember Apple does provide .Mac and its iDisk service for off-site, also nicely integrated into the OS.

  7. “Remember Apple does provide .Mac and its iDisk service for off-site, also nicely integrated into the OS.”

    I don’t know about you, but I find uploading files to my iDisk to be excruciatingly slow. It’s sad.

  8. Significantly slower. And it seems to slow down all Finder operations while copying. This might be because I’m still using Tiger — haven’t gotten around to Leopardizing my Macs yet (I’m more or less waiting for v10.5.2).

  9. Drag. FWIW, I just uploaded a 2.5MB test file to iDisk in under 10 seconds over a cable connection. Don’t think I ever tried with an eye towards speed under Tiger, so can’t compare.

  10. (For Apple Developers:) Why not give Time Capsule a feature to upload to .Mac or iDisk or whatever online backup service. The nifty device would simply back itself up to the online service in the background without “slowing down” any users.

    User backs up to Time Capsule with Time Machine

    Time Capsule backs up to iDisk (or whatever).

    That would be the best of both worlds.

  11. I use a solution from It lets me backup my mac and linux pc to my local external drive and the their offsite storage facilities at the same time. I have got a free 1GB account with them, I can squeeze about 4GB of my really important stuff to my online account but still backup 70GB of my not so important stuff to my external drive, best of all is it all happens automatically.

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