Time Machine is the part of macOS that allows you to easily back up your Mac to an external or networked hard drive. Here are some of the most asked questions about Time Machine, such as what size hard drive do you need, can you exclude files from the backup, and how do you restore files from the backup.
You can also watch this video at YouTube.
Watch more videos about related subjects: Backing Up (18 videos).
You can also watch this video at YouTube.
Watch more videos about related subjects: Backing Up (18 videos).
Video Transcript
Hi, this is Gary with MacMost.com. Today I'm going to answer some of the most frequently asked questions about Time Machine.
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So Time Machine is something we should all be using to back up our Macs. But you may have some questions about why and how it works. So first should you be using Time machine to back up your Mac? The answer is definitely YES. Hard drives fail. Computers fail. Computers are stolen. Disasters happen. Having a back up of your data is very important. But what if you're using iCloud. I often hear people say, well I'm backing up to iCloud so I don't need Time Machine. If you use iCloud to store all of your documents, all of your photos then it is true you do have copies of that on Apple servers. But it's still useful to have a Time Machine back up to have that stuff backed up to another drive locally. Drives are cheap. So why not have an extra back up of your data.
Plus, Time Machine allows you to go back and look at older versions of your files. It's very important if you made a change that you regret or if you deleted a file and now you want it back. So Time Machine backs up your entire drive. Everything. System files, library files, things like fonts and all sorts of settings and preferences. In fact if your drive fails or if your computer is stolen you can recreate everything on your computer by restoring from a Time Machine back up.
So what sort of drive do you need? Well, there are two ways to back up using Time Machine. One is with the drive directly connected to your Mac. You can do that with a desktop computer like an iMac or if you have a MacBook but it mostly sits on your desk and doesn't move around. In that case any USB3 drive will work. You can find a ton of them, and they're really cheap, if you look online at sites or go to a local computer store. Now if you're backing up a MacBook that moves around a lot and is rarely sitting on a desk, so you don't want to plug in an external drive all the time, you can connect an external drive to most wi-fi routers. They'll have a USB port, you can plug it in, and then you can access that drive as a network drive. You can choose that as your back up drive.
What size drive do you need? Well, a general rule of thumb is to make it at least twice the size of the data you're backing up. So if you have a terabyte drive on your iMac and you're using most of it you should have a 2 terabyte drive, at least. I would say that at minimum have a 1 terabyte drive. So even if you have a 250G drive and you're not using a lot of it, drives are cheap, so why not get a terabyte drive and back it up. The larger the drive you've got, the more of a history will be kept. So not only will you have every file on your Mac now but you'll also have a history of changes to files and files you deleted going back months and even years.
So formatting a Time Machine drive isn't really something you need to worry about. It's automatically formatted when you choose it to be your Time Machine drive. It's formatted using the old Apple file system which is all that Time Machine works with right now. So I get this question a lot. Should I buy a SSD or an old fashioned spinning hard drive? Most of the time a back up is just writing out the back up files to the drive. Speed really doesn't matter. So getting a SSD is a waste of money. In fact if you're connecting to it using USB you're not even using the SSD at its full speed. The bottleneck is in the cable not in the drive speed. So getting a hard drive for a back up is perfectly fine.
So as you make changes to files and delete files and replace them with others what happens when it fills up? All it's going to do is start deleting older versions files. Time Machine is always going to keep around all the files you have currently on your drive so you have a complete back up for a restore. It's going to keep as many old versions and old files that have been deleted around as it can.
So it's common to actually back up more than one computer to a drive when you have a house of MacBooks. You've got a drive connected to your network drive and you're using that same drive to back up two, three, or four MacBooks in your house. That's normal. In that case you want to make sure that drive is big enough to handle all of that. But otherwise if it's a drive connected directly to your Mac you should have one for each Mac. That way you don't have to disconnect it and move it around. Drives are cheap so why not have a back up drive for every desktop computer.
Now, this is a big mistake I see people make all the time. They get this nice new external drive, maybe they've never had an external drive before, and they think, ooh, I can put other things on it as well. Drives are cheap. You should only use your Time Machine back up drive for Time Machine backups. In fact putting other files on it will sometimes mess up Time Machine which is trying to manage the files on that drive moving older versions and older files to make room for newer ones. If you're always putting new things on it or changing things on the drive it could lead to issues. So get another external drive if you want to have an archive drive or something like that.
But how about the opposite. How about having more than one back up. You can do this. You can actually plug in a second drive and assign that as a Time Machine back up drive as well. This is commonly done in situations where you're moving the Mac around. Like if you take a MacBook between home and work you can have a Time Machine back up in either one.
So setting up Time Machine is pretty easy. As a matter of fact if you don't have Time Machine setup and you buy an external drive and you plug it in Mac OS will prompt you asking if you want to use this drive as a Time Machine drive and then everything just gets set up automatically. But otherwise you can go into System Preferences, Time Machine and then you can select that disk as a drive and everything else is pretty automatic.
Time Machine backs up things hourly. A common question is people say well can I have it do it less? The answer is you really don't want it to. Because if you have it do it less that means it's going to be doing more work with each back up. An hourly back up is only going to back up things that have changed. It's an incremental back up. So it should be fairly quick. Now there is a way to exclude things from your back up. You can go into Time Machine, Preferences, you can click Options, and there you can add exclusions. This is useful in cases where you have things you know you don't want to back up.
So what if you have an external drive that has some data on it and you want that backed up as well. Well Time Machine can back up external drives attached to your Mac. What you want to do is go into those exclusions and make sure the external drive isn't listed there. By default it will probably be added to that list. So you simply remove it from the exclusions and now Time Machine will back up your internal drive and that external drive as well.
So Time Machine isn't just for a disaster like if your computer is stolen or the hard drive fails. It could also be used to turn back time when you've made a mistake. For instance what if you accidentally delete a file or a folder full of files and you realize it a week later. You can use Time Machine to get those back. You can even use Time Machine to get back files that you've changed. So, for instance, you're working with a PhotoShop document. You make some changes to it and you realize I really want to go back to how the file was yesterday. You can use Time Machine to grab that old version of the file.
So restoring a file from Time Machine is a little weird. What you want to do is go to the location of that file. Then activate Time Machine and it will give you this view of the folder that allows you to go back in time. Select the file and then hit Restore to restore a copy of that file. You can have it Replace the current file or have it appear as a New File. If you have any other questions about Time Machine be sure to ask them in the Comments.
I use 2 drives (Time Capsule + La Cie) for Time Machine backup. Logically I guess both drives shall contain the same. However, if I want to restore a file, how do I choose the one or the other drive when I start Time Machine?
Mistakenly deleted a backup cant empty trash any suggestions please
Great info on TM. I currently use three TM drives in separate enclosures. I have one of those TM backups that is store off site. I had a hd enclosure firmware problem that wiped out both of my on site TM's my third off site saved my life. I update that off site TM once a month; unless I have something really important. I am very careful about my backup routine. Thanks again for all you help.
1.I have a older Time Capsule (the flat pancake version) that still works fine. But now that I have a Netgear Orbi mesh router, I have it packed away in a box doing nothing. Can I repurpose it as a Time Machine backup drive without using is old n-router?
2. I'd love t see you create an instructional video on how to connect an external drive to a router (like my Netgear Orbi) and use that as a whole house network Time Machine backup drive for our many Apple computers (desktops and laptops).
Jan: So you have the two drives connected at the same time? Usually, you have only one connected at a time (one at work, one at home or something like that). I'm not sure what will happen when you try to restore. Try it and see.
Stephen: It sounds like you made the mistake of trying to directly edit the Time Machine drive, by moving the backup to the trash? Your best bet may be to just erase the drive and start Time Machine backup from scratch. Be careful.
Mr. Luigi: You may be able to figure it out with experimentation, but I'm not sure it is worth it. Drives are cheap and that is an old one, right? As for a tutorial on networked drives -- there are too many different brands each with their own setup tools and software. One on that specific router would only be useful for the few with that router.
You mentioned that you can connect an external drive to your router which would allow network back-ups without having to plug into a laptop each time. Is there any concern about security or privacy with this set-up (my internet provider furnished me with an AT&T router).
I currently connect an external drive to my MacBook Pro 2x per week and place the drive in a secure location during non-back-up times. It works fine, but your way would be much efficient all around.
Thanks again
Larry: So the concern would be that your ISP would be spying on you and looking at your backups? But if that was the case, then wouldn't they also be spying on your computer directly and your Internet usage? I'm not sure what the additional danger would be by doing your backups on your local network.
Good morning Gary. You said. “You should only use your backup drive for ΤΜ backups.”
What you said it is correct. But also you can create a partition on a disk so to use it only for TM backups. I’m doing it over 7 years now on my two 4TB USB 3.0 external drives without any problem. Really nice video! Keep going the excellent work!
Dimitris: So you are partitioning your external drive and using on partition for a Time Machine backup, and the other for something else? This is a very bad idea for three reasons. First, how are the things on the other partition being backed up? If they are being backed up to the same Time Machine backup, then the original and the backup are on the same drive, making the backup kinda useless. The drive fails and you lose both copies. Second, you are now using the drive for two things, so shortening the drive's life as it is used more. Third, you have less space for your Time Machine backup so it will not be able to save as much of a history. My point is that drives are cheap. Your data is valuable. Use the 4TB drive just for Time Machine and get another drive for whatever else you need.
I have created a redundant Time Machine backup on my Synology NAS, by following Synology's directions to create a special user for the Time Machine --- and it all amounts to creating a Sparcebundle disk image within which to stash the Time Machine for my MacBookAir. It all works just great, but for only a few months and then I get the message that Time Machine needs to start all over from scratch, trashing all the version copies that have amassed along the way - creating a brand new backup
I have 2 external disks, 4TB each. I have one partition about 400GB on each. My system is only 70 GB. It's not necessary to use 4TB and keep a TM history for the whole year. It is meaningless to make a restore 4 or 5 months back. For what reason? The other data on my external disks is only movies, music and some pics. Personally I don't backup these files. It's not necessary. I have no problem with my 2 WD disks all these years. You never know. :)
After all, the TM doesn't work perfectly! It is not so trustful as it is expected to be or as Apple says. It has too many problems. Everybody knows that. Personally I use Mac for over a decade and I have seen a lot. Making a clone it is a better idea some times or using a program like CCC.
Ron: Sounds like the NAS isn't up to the task, that's my guess.
Dimitris: It is meaningless to make a restore from 4 or 5 months back ... until you need to. Is it so far-fetched to think of an example? Say you are doing your taxes one year and that document from 11 months ago is missing. Or you get a request from a "client" (supposing you do such work) requesting something from 2 years ago and find you cleared out that folder a year back?
Time Machine doesn't work perfectly and never will as long as hard drives don't work perfectly either. Clones have the same issues, and more. Delete a file by accident and then update your clone and you'll delete that file from the clone too.
It depends on kind of use. There are differences between a home use and a business use of a Mac. Definitely, you can not trust TM for keeping backups for over a year. It's a very bad idea and completely wrong. Every year Apple changes the macOS with many updates. Who can guaranty that everything will work just fine? Nobody! This is because even the macOS isn't perfect. If you have extremely important documents like tax documents as you mention above, it is a very good idea to keep hard copies...
...somewhere and don't rely only on technology. I can write too many things about Time Machine backups, clones or simple copies on disks, USB flashs, cloud services, about macOS problems, etc. TM is a good solution to keep backups but the most important thing on this is that nobody says that one disk for backups is equal to nothing. TM is a long story and never ends. Use it but don't trust it!
My new Seagate backup is indeed on the exclude list. I need details on how to remove it. On the "exclude" pop-up, the "-" box does not respond. The "+" box sends me to Applications. Need help. Thank you.
Don: Select it in that list, then click the - button.
Don: Also, you can use the tmutil command but you need root privileges. Open Terminal and type: sudo tmutil removeexclusion -pv /Volumes/volume_name. (volume_name = the name of your volume). The easiest way is to type the command, sudo tmutil removeexclusion -pv, open a Finders window and drag&drop the volume. Hit Return, give your password and hit Return again.
What is the cause of the sparsebundle error(s) that seemingly occur with annoying regularity- resulting in having to expunge the old backup and start over?
Paul: I haven't heard of that. Perhaps an issue with your disk?
Hi Gary, can you comment on Pros and Cons of SuperDuper vs Time Machine? I currently have an old external drive that is now too small and so need to change this and am wondering if I should stick with SuperDuper or move to Time Machine when I upgrade. Thanks
Ian: I did a video on that: https://macmost.com/stop-cloning-your-hard-drive-as-a-backup.html
Thanks Gary. I've just watched the video and most informative. Guess I'll be moving to Time Machine!
Gary. If you have two (or more) drives connected to the Mac Time Machine will alternate backups between the two (or more) drives. This gives, I feel, protection against a Time Machine drive failure
Hi Garry, great video. I just wondered about Time Machine encryption. I formatted an external disc using Disc Utility encryption, because if I use Time Machine to encrypt it take a very long time to back up, is what I have done correct?
Thank you,
Robert
Robert: Does it work? It is certainly not the way I would have done it. I use Time Machine encryption. It shouldn't slow things down by a noticeable amount. Not sure what the consequences are of the way you are doing it.
Hi Garry, it does work, I have a 2011 MacBook Pro 1TB ssd and use 1 TB WD external drive, when I first set up using Time Machine encryption it too a very long time to back up even after the second back, do you know roughly how long it should take to back up?
Thank you,
Robert
Robert: How long an initial backup takes depends on the amount of data on your drive (size and number of files), the speed of the drive, the speed of the backup drive, and the speed of the connection between them. Also the condition of the backup drive plays a big part.
Gary and Robert: Both ways are correct and work just the same! The first option from System Preferences, allows you to keep your old backups because you can retroactively encrypt your existing Time Machine backup. This can take a long time. Selecting the second option, from Disk Utility, you have to erase the disk first but it's quickest than the first option!
Gary, I use 2 external drives as backups which I alternately plug into my MacBook Pro. I didn't realize you could use an external drive attached to a router as a Time Machine backup. So, could I plug one of my existing drives into the router, select that as a TM backup and have it pick up from where it left off, i.e., retain all the existing backups?
John: I've never tried it that way, so I'm not sure, sorry.
You mentioned that Time Machine will back up an attached external hard drive. Will the information on an attached flash drive be backed up also?
Bill: As long as it is not on the exclusions list. Check there, and remove it from the exclusions.
Hi Garry, ok thank you. Maybe I will try again and see what happens. Thank you.
Can one Back-up an iPad please?
Dirk: You back up your iPad to either iCloud, or your Mac/PC. To check to make sure iCloud backups are on, go to Settings, click your Apple ID at the top of the left column, then iCloud, then iCloud Backup. To backup to your Mac/PC, connect your iPad, launch iTunes in the Mac/PC, select the iPad, and click the backup button.
Newbie & potentially dumb question: I have a 2017 MacBook with one usb-c port & I don't want to have an external hard drive attached all the time. Could you direct me to a video that explains how to set up the hard drive on my network/router? hope I have explained myself clearly. TIA Julie
Julie: There are many different models of routers with different configurations and abilities and different ISPs. I don't know which you have, so I can't advise you. Even if i knew, I wouldn't have that router so I wouldn't be able to help. Check any documentation you may have, or call the tech support from the router or your ISP, if it is their box. Otherwise, you may need to get a local tech helper to come and set it up for you.
I have been using Time Machine backup on an external drive with other files. It's now out of space so I bought a new 4GB drive. I had no trouble setting the first drive up. The new drive came with some extra software for Mac and PC. So I ran the Mac software first. Then I tried to set up Time machine as a new backup on the new drive. It wouldn't do anything. Should I move the backup first to my computer (if it fits) and drag it to the new drive and continue on as if it's the old drive?
Diana: No, don't move the backup around like that. First, I don't know what "extra software" came with the drive, but don't use it. When you set it up as a Time Machine drive, it will erase the drive and format it correctly. Then don't do anything else with that drive. Just let Time Machine manage the drive. Don't put extra files there or mess with it. If that "extra software" has already messed up the drive and you haven't even use it yet, then just use Disk Utility, erase the drive, and start a backup to this new drive from scratch.
Time Machine seems to very slow at times, for example it will say "Backing up: 63.4 MB of 256.1 MB; about 50 minutes remaining." 50 mins sounds like a very long time to back up less than 200 MB. The 500 GB external drive is full so it will be dropping off the oldest data - is that maybe why? On my Mac (2013 iMac) I have about 225 GB. Thanks.
Jane: Probably cleaning out old data, yes. Could also be slowing down the backup because it recognizes you are using the computer and I will give you top priority and the backup low priority.
When I get a Time Machine warning: "You are backing up an encrypted disk to an unencrypted disk," is that a call for action on my part? What are the implications of taking no action here?
Ron: It depends on how concerned you are about the security of your backup. You have FileVault turned on on your Mac (encrypted) to protect that data if the Mac is stolen. But if the Time Machine drive is stolen, then that data can be read. If that is a concern for you, then you should start a new Time Machine backup and this time set it to be encrypted.
Hi Gary. I use 2 usb drives connected all the time to backup my 500gb SSD drive but I have a third external drive for iTunes. approx 850gb. it seems that TM backs up both Mac & iTunes drive which is perfect. But.. if I buy a new Mac and use Restore to setup, what happens about the external drive with iTunes on? should I connect during Restore? or will the system 'see' there is another drive, but not present until the full restore is complete and check back later? Thanks Great video - again :-)
Jonathan: You would use Migration Assistant, not a Time Machine restore, to set up your new Mac from your Time Machine backup. It will restore that user account and all the files in it (Documents, Desktop, etc). Since your external drive files aren't in there, it won't do anything with them. You should just connect it and point iTunes to it and you should be set.
I've used TM for a few years and only recently discovered that none of the desktop folders were backed up. I had folders for photos, music and movies, for example and all of them contain 0kb. What's the problem that the things I most wanted backed up weren't? How can I fix this?
Richard: What do you mean that "folders ... contain 0KB"? Are you trying to look at the folders in the backup directly? They aren't meant to be viewed that way. Try restoring a file from one of those locations and see what happens. (you get the option to restore and keep both the current versions and the old version so you don't replace your current file).
Thanks Gary
Thanks for the suggestion Gary. When I tried to restore the folder it wouldn't let me, but came up with "The folder “Desktop” can’t be opened because you don’t have permission to see its contents." On the folder was a red dot with a white dash in it like a wrong way sign on the road. The restore button was greyed out and wouldn't do anything. Is it possible that this is happening because I hooked up my backups to a new computer?
Richard: So you are selecting your Desktop folder in a Finder window, then clicking on the Time Machine icon in the menu bar, then choosing Enter Time Machine. Then after Time Machine launches, you see a 🚫 symbol on that folder? Very strange. Not sure what you mean by that last sentence -- hooked up in what way? Maybe time to visit the Genius Bar with this since it sounds like you've got something going on.
I agree it is strange. The process you described is exactly what I did. The symbol aside, why does it say I don't have permission to see the contents of the folder? On my old mac I had 2 external hard drives for backups. I connected them to my new mac via usb. Sorry if my wording was confusing.
Richard: No idea. Hard to know without being there to diagnose.
Thanks for your time and expertise. Even though you didn't give me the answer directly, sharing this problem with you did help me find the answer. When I changed computers I also changed my admin user name. By changing accounts to my old admin user name all my old backups were opened.
Last month, I replaced my old Seagate backup with a new 4 TB Seagate, and it is working great, but I notice on Time Machine Preferences, "Select Disk", that even though I have only one backup disk, there is a second available disk that is labeled "Case Sensitive", and even though it is not the selected disk, it appears to backing up as well. What's the story? Thank you.
Don: Hard for me to say without seeing it.
Hello Gary,
I do not use my old macbook air very often. I used to backup the macbook air using Time Machine to 2 different drive external drive in an alternative schedule. Now I want to know Is their a way I can consolidate them into one drive? In other words will I be able to move all the Time Machine backups of one drive to another drive? If so how to do it?
Lali: I wouldn't bother with that. Just start a new backup for the Air on the drive you want to use for both. Many people use a networked drive in exactly that way. Start the new backup and keep the old drive around for a while since it has over versions of the files. Then eventually you can get rid of or repurpose the old drive.
Hi Gary,
I have lots of video on two separate externals. I back them both up via TM (I use 2 TM drives for redundancy and they alternate). Problem is I'm running out of room on the TM drive. Is it possible to tell one TM drive to back up *one* of the externals, and the other TM drive to back up the *other*?
Miles: I can't think of a way. One solution is to back up those externals another way (third-party app). Or, you could just get a larger TM drive, of course. You could also backup some of the older videos that you no longer need to modify to another drive, then exclude those folders from your TM backups.
Oh good suggestion - thanks Gary!
Hi Gary,
I use a 2 TB external WD drive to manually backup my MacBook Pro on a monthly basic since I am not changing the data on my MacBook Pro often. When the 2 TB drive gets filled say in a year or so if I want to delete the oldest TM backup how to delete them? Will I be able to delete from oldest backup date?
Lali: You don't delete anything. Time Machine will keep the latest version of everything and older versions as space permits. Just keep backing up and it will maintain itself, removing old items to make room.
Hi Gary,
Thanks for the suggestion, I will follow it
L