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Beginning Mac: Time Machine

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Backing up your computer is an essential task that many of us neglect until something goes horribly wrong. With OS X Leopard, Apple (s aapl) has made it much easier to ensure that your data is always backed up and protected through a feature called Time Machine.

Time Machine is an application that automatically synchronizes your computer hard drive with another storage device every hour. Reverting to an older version of a file is simple, facilitated through an interesting ‘space-like’ interface.

This article will provide an introduction to Time Machine, explain how best to set your computer up, and the process of restoring a backup if you accidentally delete data or suffer a hard drive failure.

What You’ll Need

timemachine_hdicon20071016There are two main requirements for using Time Machine. First is a copy of OS X Leopard — older versions of the operation system don’t include the backup software. Second is an external hard drive.

I’d generally recommend buying the largest hard drive you can afford. The more capacity, the more room there is to store older files (and the further back in time you can go to restore a file). At the minimum, the drive should be bigger than the internal drive in your Mac.

Apple does offer a dedicated router/hard drive combination called Time Capsule, coming in either 500GB or 1TB varieties. If you’d like a all-in-one network router and backup drive, it’s a great option — if you plan on using it solely as a hard drive, it does work out expensively.

Setting Up Time Machine

The quickest way to get started with setting up Time Machine is simply to plug in your new hard drive. OS X will recognize that you haven’t used the drive before, and ask whether you’d like it to function as a Time Machine backup. Alternatively, head into System Preferences, select Time Machine, and choose your new hard drive from the list of options that appear.


Once set up, Time Machine will begin to back up your drive for the first time. The initial process will copy every single file from your computer’s hard drive to your backup drive. This could involve copying many thousands of files, and will likely take a couple of hours. Be patient, and choose a time when you won’t need to unplug your laptop or power down the machine.

The speed will also depend upon how the hard drive you are using is connected. If plugged in directly via USB (as most will be), the process will be relatively quick. If you’re using a Time Capsule or other networked hard drive you may need to be prepared for a slightly longer wait.

After the initial process Time Machine will only copy files that have been added or changed in the past hour, making future backups far quicker. You’ll find that the following backups are kept:

  • Hourly backups for the past 24 hours
  • Daily backups for the past month
  • Weekly backups until your backup hard drive is full

Changing Options

There are very few options to tinker with when setting up Time Machine, but those that do exist are worth noting.


Firstly, you are able to specify a number of files or folders which you’d like Time Machine to refrain from backing up. This isn’t usually necessary, but can be handy for large files which you don’t need to keep safe.

In addition, you can tell Time Machine not to back up when your laptop is running on battery power to conserve energy, and specify whether you’d like to receive a warning when older backups are deleted.

Restoring Individual Files

Should you lose a file or accidentally delete it, open the folder which used to contain the file, and launch Time Machine. You’ll be presented with a window similar to the following:


Clicking the arrows to the right of the screen will go forward or backward in time, scanning through the various backup dates. It’s possible to take a closer look at a file through Quick Look, by selecting a file and pressing the Spacebar.

When you’ve found the file to restore, select it and press the ‘Restore’ button in the lower right corner. Time Machine will exit and copy the file back to its original location. If it would involve overwriting an existing file, it will ask you what action you’d like to take. Easy!

Restoring an Entire Backup

If the worst happens and you suffer a hard drive failure (or, on a more optimistic note, buy a new Mac!) you may need to copy everything back across from your Time Machine disk. Again, this is a fairly simple process.

If you’ve purchased a new Mac, you’ll be asked when setting it up whether you would like to ‘Migrate’ from a Time Machine backup — simply agree, and follow the instructions to proceed.

If you are booting from an installation CD (after suffering a hard drive failure), select the ‘Utilities’ option from the menu bar, then “Restore from Time Machine Backup.” You then select the Time Machine drive you wish to restore from and follow the simple instructions. Your Mac should be back up and running in no time!

Other Solutions

If you’d prefer not to use Time Machine, there are a couple of other options available:

  • Use a utility to create an entire “clone” of your hard drive onto another on a regular basis, such as SuperDuper!
  • Use an online service such as Dropbox or Syncplicity to backup important files and documents to your online storage space


Time Machine provides a simple, ‘set it and forget’ backup solution. You’ll need to spend some money to pick up an external hard drive, but I guarantee it will seem worth it when you accidentally delete a set of family photos, an important business document, or your music collection.

Restoring is simple, and it even makes the process of swapping to a new computer almost seamless. Remember to pay attention to any error messages which may pop up occasionally, and regularly try to restore a file (just to check that your backup is functioning as it should)!

Hopefully you’re now all set up and ready to sit back and relax while your Mac keep itself well protected.

32 Responses to “Beginning Mac: Time Machine”

  1. Kaitlyn French

    I took a photo i’m not proud of on photobooth that i’d rather nobody saw and I’ve deleted it and emptied my trash. This was maybe three weeks ago or more. I still have not set up time machine. If I set it up, will the photo be recovered? I would prefer it to stay deleted.

  2. Hi people, I am a relatively new Mac user so you could call me a noob, tho I am fairly tech savvy so can find my way around day to day problems. I have a MacBook Pro with an intel 2.26 dual core, 2GB RAM, 160GB internal HDD and OSx SnowLeopard.

    Due to having my HDD fail just a few months into having my new Mac I lost a lot of data as it wasnt backed up. I am now looking to start using time machine and carbon copy in conjunction with each other to avoid future problems of this nature.

    I have bought a WD MyBook 1TB Ext HDD and partitioned into 1 x 200GB and 1 x 800GB partitions (The 200GB for carbon copy to use for a complete clone of my internal HDD and the larger 800GB for TimeMachine to use as it pleases till the space runs out)

    The rest of my data (Pictures, vids, music etc.. is all stored on another 500GB HDD which is backed up independently via other methods)

    I wanted to know a few things.. firstly how easy is it to backup the other external drive containing all my media using timemachine, is it simply a case of removing the media drive from the exclusions list? Also does timemachine compress the data very much? and are there any ways of checking the backup for corruptions / differences to the original data contained in my internal HDD.

    Also there have been some issues noted with Mac OSX relating to system issues after downloading and installing system / software updates whilst running on battery power. In some forums people have aknowledged this problem to be as severe as causing systems to hang and refuse to boot = not good!! Would this apply to allowing timemachine to make backups on battery power? I am just being over paranoid and want to know these things as I never want to lose my data again and as im a new mac user and a timemachine virgin its kind of nice to know how the system works and the integrity of my backups etc…

    I know this is a long rant but any replies are most welcome.

    Many thanks guys,

    Stevey R

  3. I am backing up my entire harddrive right now with time machine.
    the reason was actually to be able to delete my iphoto library for example, because my intern HD is full and my mac is getting lame.
    will i loose my iphoto files or are they still in the backup? thanks!

  4. quick question please.
    if i can’t currently fit all my files on my imac hard drive (ie, i keep all my photos on the external drive) then how do i go about backing everything up and in one go… how can i ensure that files i don’t set and forget in time machine will still be there if it continually backs-up the imac?

  5. So I have just gotten a 1-TB Western Digital MyBook, and am wondering now that I’ve backed up my files with Time Machine, if I were to delete a file on my MacBook Pro, would it be removed from the MyBook?

  6. You know, I just went ahead and let Time Machine do its thing, but really, what I want is to be able to make space on my MacBook Pro HD. I make videos and I want to delete the source files, cuz my 120 Gig drive is jam packed full. I’ll be getting a new mac in a few months (since my laptop is close to 2 years old), and the whole “delete old files” checkbox makes me very nervous. What do you mean delete? Excuse me? Just save the most recent version of a file name, overwrite old files with the same filename, and allow me to delete stuff off my HD. Right now, I’m making manual backups, but that’s quite time consuming.

    • David Field

      Yes, that’s right, but I don’t think you can use the TimeMachine HDD for anything but Timemachine. You would require an additional HDD for the archive.

      The following backups are kept on the Time machine HDD:

      Hourly backups for the past 24 hours
      Daily backups for the past month
      Weekly backups until your backup hard drive is full

      So 1Tb would last a long time but your files would eventually be overwritten

    • To answer an old question. You can use the Time Machine HDD for other backups as well. I do that for my Mac and the external iTunes HDD. You just have to make separate partitions on the HDD. 1 Partition for Time Machine, large enough for your backups and 1 partition for each extra archive. You can use the Disk Utility for that. Start Disk Utility, select the Partition tab etc. Just remember that partitioning will erase all previous data, so you have to make a new full backup.

    • Tyler Munson

      Here’s a new question on an old theme. I have 1 external drive that I use as an archive. I have a second external drive that I use for Time Machine. If I have Time Machine back up both my internal drive and my archive drive, and then I unplug my archive drive for a year, will Time Machine eventually write over the archive?

  7. I’ve just done my first full disk backup. This may be a silly question but I wanted to ask, if I now go and delete a bunch of stuff on my main hard drive – when Time Machine does it’s thing again will it keep the files I deleted? (Not sure because it deletes previous backups / and does it’s own thing in the background)? that background stuff sort of freaks me out a little; )

  8. CheshirePlain

    Hi, I intend to use Time machine on imac for proposed back up, non business
    personal use,Photos, Music,Files, etc. Can someone recommend a QUIET.
    Ext, Hard Drive 1tb. Suitable for Time Machine . I am told external Hard Drives
    can be noisey & intrusive !

  9. Does anyone know how to limit the size of memory used to store your back up via Time Machine. I have a 250 gb external hard drive and only want to use part of it solely for my time machine. I read something about sparsebundles and the use of your cpu’s terminal but I don’t know how all of it come to play or if my mac even has it? (sparsebundle?) I’m lost and new to the world of mac, I need help please.

  10. Jon M. Buntenbah

    Question actually : even thought I’ve checked the box to have Time Capsule show in my menu bar it doesn’t. Any ideas ? Also I understand there’s a dock icon. Where would I find that ?

  11. I am confused, can u take your computer back in time, to before you have ever backed anything up? This is annoying because i have a school mac and want to back up my stuff, but our anal tech won’t let us use it because he is worried about this happening, because we could then take it back in time to before he did anything to it…Will u please help!!!!

  12. Hi Team,

    Ok, I’m a noob to Mac but have made the quantum leap and invested in:

    Mac Mini (used as media centre)
    External 500GB Hard Drive (contains all my videos, iTunes and Photos – approx 120GB of content on it)
    Mac Time capsule

    So I have set everything up and it work, the Mini is fine, iTunes and Photos play. Time Machine connects and is backing up to Time Capsule.

    Here is my problem: Time Machine is only backing up approx 17GB in the 1st back up run! I have moved the external drive from the ‘exclude’ option so in my mind the external drive (well iTunes content & photos) should be available for back up to Time Capsule via Time Machine but as I stated it seems to be only backing up 17GB!

    What have I missed doing? Will Time Machine back up external hard drives that are attached via USB to the Mac Mini?

    Thanks in advance.


    • Hey Mike,

      I am having the same problem (just got a macbook pro a week ago); I have an external hard drive I am using with Time Capsule and another external hard drive I put all my music/videos etc. I was just wondering did you ever figure out how to make Time Capsule encompass the external hard drive with all your files? I know you have to include the files under the Time Capsule set up options but it seems like Time Capsule won’t back up the files on my external hard drive for some reason.


    • David Field

      I have an external HDD which is backed up by TimeMachine. I can’t find where the setting is but I think when I originally attached the drive there was an option whether to allow time machine to back it up. It may have come up automatically.
      Sorry not to be of any better help, but it is possible to have TimeMachine do it.

  13. joshua bartos

    could i use an additional internal drive?
    i don’t want to have the clutter of external drives on 4 machines in a video editing lab.


  14. David Field

    I had a file corruption on one of my widows programmes that I run through parallels desktop. Time machine is set to back up my windows files as well but I cannot find a way to retrieve any of the windows files. Does anyone know how to do this?

  15. Hi,

    You also forgot to mention that when you perform a restore (after a Disk Crash), Time Machine will create a BRAND NEW/FRESH (FULL) Backup of your Hard drive on the Time Machine Backup Drive.

    All the original & incremental backups you’ve taken (before the crash) are no longer linked/available with the new (FULL) restore you’ve done. Neither is there any way to access it back.

    This is a very very huge gap in the capability.

    • I have a LaCie external hardware drive and it was a reasonable price, this is where all of my time machine backups go, as well it holds all of my photo’s. It has a huge capacity. Time machine is great and with the external hard drive I will never lose a thing. Doesn’t matter what you own for a computer, it only makes sense to have an external hard drive for backing up your information.

  16. You might want to visit the above URL which gives you a detailed walkthrough on how to configure Time Machine to work with a networked attached storage and without the need of a TimeCapsule. This is ideal if you have NAS storage such as Synology or QNAP and don’t want to spend more money on TimeCapsule.

  17. Marc Schwartz

    I did not see any mention of what I understand to be compatibility issues between Time Machine and File Vault. As I understand it, Time Machine would see the File Vault user area as a single large file, not as a normal file tree. This becomes an issue whereby one cannot use the Time Machine GUI to retrieve and restore individual files from a File Vault protected system. One must use the Finder.

    Any comments on this or how this may differ with SuperDuper or other apps?

    I have seen references to other options such as using rsync based incremental backup approaches like rsnapshot. The downside to using rsync is the inability to take advantage of the HFS file system flagging for changed folders. It is this flagging that enables Time Machine to be efficient in identifying changed files, versus actually checking each file individually for a change.