Consider Special Backup Needs
Although duplicates, versioned backups, and offsite storage cover most situations the typical user will encounter, some people have special backup needs that don’t quite fit the mold.
I’m thinking, for example, of users with vast numbers of digital photos and those who Deal with Huge Volumes of Data because they work extensively with the gigantic files required for digital video or pro audio apps. In other special cases, you may need to Back Up While on the Road (especially photos) or Back Up Windows Files and Volumes.
Each of these situations may require additional steps beyond conventional duplicates and versioned backups.
Back Up Digital Photos
If you have no more than a few gigabytes of photos on your Mac, you can back them up along with the rest of your data and not take any special steps. But the ease of snapping photos and videos with an iPhone or iPad, and the increasing resolution of files from iOS/iPadOS devices and digital cameras, has increased the likelihood that a Mac user’s photo library will extend to tens or even hundreds of gigabytes (my own is over 150 GB—yikes!). With the growing number and size of your images, you may find that duplicates and versioned backups alone don’t meet all your backup needs.
Luckily, numerous tools, services, and strategies exist for the express purpose of making photo backups as painless and secure as possible. Consider these options in addition to (or, if you prefer, instead of) duplicates and versioned backups.
iCloud Photos
If you manage your photos with Apple’s Photos app, you can take advantage of iCloud Photos to store copies of your photos offsite. It’s not exactly a backup, but it provides at least some protection for your photos. (If you don’t use Photos, there’s nothing to see here; move along to Photo Sharing Services.)
The basic idea of iCloud Photos is that all your photos and videos from Photos sync to Apple’s servers, and from there to all your other Macs and iOS/iPadOS devices. Although that sounds both simple and wonderful in theory, in practice it’s an odd and confusing process. I spelled out all the details in my TidBITS article iCloud Photo Library: The Missing FAQ, which is still largely accurate even though it’s several years old (and Apple has switched from the term iCloud Photo Library to iCloud Photos).
You’ll have to pay for storage above 5 GB of data, though prices are roughly in line with most online storage and backup services. It’s probably worth it for the convenience of having the same photos on all your devices, not to mention easier sharing.
But even though iCloud Photos stores copies of all your photos in the cloud, it’s not quite the same thing as an online backup. The difference is that if you delete or modify a photo on one device using iCloud Photos, that change propagates to all your other devices. (In this sense, it’s a bit like IMAP email: the server holds the master copy of each item, until the client says to delete it; then it’s deleted from all clients.) You do get 30 days to recover anything you accidentally deleted, but that’s not much of a safety net. If you realize on day 31 that you deleted a photo you need, you’re out of luck. With conventional backups, by contrast, you can usually decide how long backups are kept (which can be indefinitely).
Even so, if you can afford the storage (and the bandwidth—iCloud Photos transfers an enormous amount of data), it’s not a bad idea to use it as a partial solution to photo backups.
Photo Sharing Services
If iCloud Photos isn’t for you (or if you want to supplement it with a service that makes it harder to lose your photos), there are many alternatives. Numerous services provide unlimited storage for your digital photos, along with complete control over which ones are shared and with whom, sometimes for as little as zero dollars! Beyond the basics of photo storage and sharing, such services differ in the selection of features they offer. Most offer prints of your digital photos for a fee; some will send you CDs or DVDs with backups of your photos too.
Because the choices (and details such as prices and storage space) change so frequently, I’ve put information on photo sharing services in the online appendixes, where I can more easily keep it up to date.
The main catch with these services is that you’ll give up integration with Photos (assuming Photos is your preferred photo cataloging app). Another catch (as with iCloud Photos) is that you’ll need a robust broadband connection with plenty of bandwidth and a generous monthly data allowance.
If you can pass those hurdles, then considering that you can back up all your photos at little or no cost using sites of this sort, it’s almost a no-brainer. Although you may already include your photos in your duplicates and versioned backups, another offsite backup never hurts—and you’ll get easy photo sharing as a bonus.
Cataloging Software
Apple’s Photos app replaced iPhoto and Aperture, but all three apps are (or were) consumer-level apps that weren’t designed for professionals—or for amateurs who have tons of photos and take their images seriously. When your photo management needs outgrow Photos, you’ll have to look elsewhere for serious image-cataloging software.
For macOS, you have three main choices (apart from high-end client-server packages):
Although these apps aren’t free like Photos, they offer flexible searching, contact sheet creation, and much more. Crucially for our purposes, they maintain thumbnail catalogs of all your images even if you move the original files to a different volume (and even if that volume happens to be sitting at the bottom of a pile of junk in your closet).
By using one of these apps to back up your photos—whether or not you delete the originals—you gain the ability to search a visual index for your images. When you find the one you want, the software will tell you which hard drive, SSD, or other storage device it’s stored on. (With Lightroom, cloud storage is also an option; in fact, it’s the preferred destination for your photos.)
If you choose one of these tools, you could potentially exclude photos from your regular versioned backups and use the cataloging software’s built-in backup tools for your photos instead—though extra backups, especially of your photos, can never hurt. If you use cataloging software to back up your photos (instead of, or in addition to, other software), it will dramatically increase the ease with which you can find and restore them. You can also, optionally, delete older photos from your disk after you’ve backed them up, saving room on your startup volume while still maintaining a handy catalog of thumbnails.
Deal with Huge Volumes of Data
Some kinds of data are inherently quite voluminous and therefore have special implications when it comes to backup. I’m thinking primarily of video, audio, and high-resolution photo data, which are often stored on external hard drives or RAIDs with more capacity than a Mac’s internal storage. (If you store this data on a NAS, also see the next topic, Back Up a NAS.)
Video files consume an enormous amount of disk space, and when you’re editing a large video project, the file sizes can become truly staggering, especially with 4K, 6K, and 8K video. Because of the sheer quantity of data you may generate, conventional duplicates and versioned backups may not make the most sense. You’re also likely to create numerous intermediate files between the raw footage and the final product, and deciding whether or how to back up that data can be challenging.
All this is equally true if you’re working in audio production, especially if your Mac functions as a multitrack recorder. It also holds for photographers working with gigantic, ultra-high-resolution images and for several other categories of user.
So, if you frequently generate more than a few gigabytes of new or modified files in a single day, read on for my recommendations.
Video Backup Strategy
If you regularly edit video on your Mac, you may need to adjust your backup strategy to account for these jumbo-sized files.
Video Data Types
Think about the different forms video data may take:
The raw files that you copied from your camera, camcorder, or iOS/iPadOS device onto your Mac.
A project (in, say, Final Cut Pro or iMovie) containing a selection of video files plus the information about how they fit together—not to mention music, narration, special effects, and so on. In the case of Final Cut Pro, this also includes video and audio cache files, which could be on a separate, connected disk.
A final, rendered movie, in one or more sizes and formats (DVD-ready, web-ready, and so on). Needless to say, a given project may be “final” and still undergo changes later!
Which of these should you include in your backup plan—and how?
Raw files on your disk: Your original footage (or, rather, the original footage you’ve moved from your camera, camcorder, or iOS/iPadOS device to your Mac) is especially valuable. You can always re-edit video if necessary, but having to reshoot something from scratch may be inconvenient, if not impossible. So, I suggest archiving it—at least until your project is finished—by copying it to extra hard drives and then putting those drives in a safe place away from your Mac. If you expect to come back to it much later, using a cloud archiving service such as Amazon Glacier (see BYOS (Bring Your Own Software) Internet Backups) might be smart.
Assuming you create such archives, you should exclude these files from your normal versioned backups and bootable duplicates, to save time and storage space.
Project files: The project files are perhaps the most challenging component, because you may modify them many different times. If you include these files as part of a standard versioned backup, you may find (depending on which video editing and backup software you use, and several other variables) that even a tiny change to a 20 GB video project results in the entire 20 GB file being added to each day’s backup.
So, I suggest storing backups of your in-progress project files independently of your other backups. If the storage requirements are ridiculous (as they may be), consider saving only a week’s worth of versions and then deleting older ones to free up space. Once you’ve completed your feature film (or this year’s holiday DVD) and sent it off to the distributor (or your family), you’re unlikely to need all the intermediate versions of the project files again—though you may still want the final project files later.
Final, rendered movies: When you’ve finished a project and know you won’t be editing it again in the near future, copy all your project files to inexpensive, archival cloud storage or archive them onto a spare hard drive—preferably using two or more drives that you’ll store in separate places. Then delete the project files from your regular disk and recycle your video backup disk by erasing and starting over again with a full backup of your next project.
In other words, treat your video data with the same care you give all your other files, but don’t get hung up on long-term storage of every single edit you make of every movie. The most important things to back up are your original footage, versioned backups of projects currently in progress, and your final project files.
Strategy for Other Large Files
Although video files tend to be the largest, and therefore the most challenging to back up, large audio and photo files (and perhaps others) have similar issues. Rather than lay out details for every sort of data as managed by each of the many audio and photo processing apps out there, allow me to offer some general guidance.
Set Cost and Storage Expectations Appropriately
Although you can reduce storage requirements for your backups somewhat by using apps that offer file compression and/or delta encoding, you can’t escape the fact that larger amounts of data require larger amounts of backup media. That’s going to cost money, and, especially in the case of network backups, it’s going to take significantly longer for each backup run. (For truly huge files, cloud backups are often a nonstarter unless you have bandwidth to burn.)
Keep Copies of Your Original Files
Raw audio recordings, your unedited photos as they came off your camera’s memory card, and other original files are especially important. Everything else you do (editing, mixing, applying adding effects) could be done again, however time-consuming it may be, but original audio performances or photographs can never be recreated in exactly the same form.
Of course, you don’t have to (and shouldn’t) keep these forever on your disk, but at the same time it doesn’t make sense to overwhelm your regular versioned backups. Instead:
Exclude these files from the versioned backups you update daily (in Time Machine or another versioned backup app).
Invest in an extra hard drive or two just to hold these archived files. Alternatively, if you have an optical drive, you could copy these files onto DVD or Blu-ray discs (a rare exception to my advice against using optical media), store multiple copies in a safe place, and refresh your copies from time to time (see Consider Long-Term Archive Storage). In either case, delete the copies on your disk when you’re done actively working on them.
Back Up Active Projects
For projects that are in an intermediate stage between raw media and final product, I suggest the following:
Include all these files in the regular duplicates of your disk(s), because the amount of space required for your duplicates isn’t cumulative as it is for versioned backups.
As with video, choose versioned backup software that offers compression and/or delta encoding, both of which can help you make the most of limited storage space.
Do create versioned backups of the files too, but consider keeping these backups on a drive separate from your other data to prevent your regular versioned backups from ballooning out of control. In other words, in your ordinary versioned backups to Drive A, exclude the folders with your audio or photo data, and in a separate set of versioned backups stored on Drive B, include only your audio or photo data. It may help to write a checklist for yourself to keep track of what’s where!
When you’re finished with a project, delete most or all its intermediate stages from your “big-files-only” backup, leaving just the final stage.
Unfortunately, I know of no magic bullet to make backups of large files completely painless and affordable, but these tips can help you minimize the aggravation.
Back Up a NAS
So far I’ve talked about NAS devices (see Network Storage Devices) only as a potential destination for your backups. However, if you also use a NAS as primary storage (that is, as the main or only location for certain kinds of data), you also need to think about backing up the NAS itself. Some people, for example, like to use a NAS (instead of a computer) to store photos, music, and videos for the entire family. If the data on the NAS isn’t a copy of something already stored somewhere else, it’s every bit as vulnerable to data loss as anything on your Mac.
The wide variety of NAS devices makes it impossible for me to offer specific advice here; what works on one model won’t work on another, and what’s reasonable for a small NAS with a single drive might seem absurd for a multi-drive NAS holding tens of terabytes. However, I’d like to offer some general guidance.
First, to state the obvious, you’ll need a storage destination with at least as much capacity as your NAS currently uses (and more is better, to allow room for growth). So, if your NAS has 4 TB of data, you’ll need at least 4 TB of additional storage to back it up. That could be, for example:
An external hard drive or RAID connected to your NAS: Most NAS devices have ports (typically USB 3 ports) that support external storage.
A second NAS: In some cases, you can set up a NAS-to-NAS backup that takes place without involving any of your computers.
Your Mac: Although you can back up a NAS to your Mac’s internal or external drive, that strikes me as an odd thing to do, in that the main reason for using a NAS in the first place is to have a large, independent storage space for your data that doesn’t rely on your Mac.
A cloud destination: You may be able to back up your NAS to a cloud storage or cloud backup service, just as you can do for your Mac. Although this will be time-consuming and bandwidth-intensive, it provides an offsite copy of your data, whereas a NAS-to-drive or NAS-to-NAS backup won’t help you if your house burns down or if someone steals all your equipment.
All of the options above assume that the NAS includes, or permits you to install, software that runs on the device itself. This is true more often than not, since most NAS devices are essentially headless computers, running their own simplified operating system. As long as your NAS can be mounted as a network drive on your Mac, any Mac backup software that supports network drives as sources should be able to back it up.
Assuming, however, that you want backups to run directly from your NAS, how can you know if your NAS supports backup software, which destinations you can use, and how to set it up? Look at the documentation that came with your NAS or consult the manufacturer’s website. Here are two examples of instructions for backing up popular NAS models:
Back Up Data from the Cloud
In this book, I’ve assumed that the data you want to back up is stored locally on your Mac (or a nearby device) and that the backups will go onto local media, into the cloud, or both. But what about all your data that starts out in the cloud? If you use a web browser to access your email, Google Docs for creating office documents, or any of numerous other web-based apps for creating and storing data, you’re relying entirely on that one service to maintain its own backups of your data. That process might be invisible to you and out of your control, leaving you with no recourse if your data should ever disappear.
In some cases, you may already have local copies of your online data without realizing it. For example, if your email account uses IMAP or Exchange and you access it using an app such as Mail, Thunderbird, or Outlook, you can have a complete local copy of all your server-based email messages, as long as your settings are configured properly (in most cases, your email client’s default settings are exactly what you want); however, restoring that data to an IMAP account can be cumbersome (see the sidebar Restoring Email from a Backup, earlier) unless you’re able to use Time Machine with Mail (see Restore Within Mail. The same goes for cloud-based contact and calendar data accessed using apps such as Contacts and Calendar. But these sorts of services are the exception. Any data you create or edit in a web browser most likely has no local copy.
A number of cloud providers can back up data from any of several cloud-based services (such as Google’s various offerings, Microsoft 365, and Dropbox) to a completely different cloud service (cloud-to-cloud backups), to local storage (cloud-to-local backups), or both. Here are a few examples, most of which require monthly or annual subscription fees:
Backupify is mainly geared toward business users of Google Workspace (formerly called G Suite). It backs up Gmail and Google Drive, plus Google Calendar, Contacts, and Sites, to proprietary cloud storage. It also backs up data from Salesforce and certain types of Microsoft 365 accounts.
CloudAlly has backup plans for Microsoft 365, Google Workspace, Box, and IMAP, plus other, more business-oriented cloud services such as SharePoint and Salesforce.
cloudHQ takes a somewhat different approach by syncing data between cloud services such as Google Workspace, Amazon S3, Dropbox, Microsoft 365, and Evernote in any combination you choose. If you sync to a service such as Dropbox that already mirrors your data locally, you get both cloud-to-cloud and cloud-to-local backup automatically. A free tier works with a limited set of services.
Horcrux backs up most types of email accounts (including Gmail, iCloud, and Exchange) to your Mac. It’s available as a one-time purchase, not a subscription.
MultCloud is designed primarily to aggregate and sync the data from various cloud providers (such as Dropbox, Google Drive, and OneDrive—but not iCloud Drive). I consider this approach to cloud storage to be fundamentally flawed. However, MultCloud does include a genuinely useful feature: the capability to back up data from one cloud provider directly to another, without having to use your Mac as an intermediary. A free version has limited functionality; paid plans add more data traffic and features.
Spanning Backup, another business-oriented service, backs up Google Workspace, Microsoft 365, or Salesforce data to cloud storage.
Spinbackup backs up all your Google data (including Gmail, Google Drive documents, Calendar, Contacts, and Photos) to proprietary cloud storage. Free accounts can back up 4 GB; paid accounts cost $4 per 50 GB per month.
Do you need one of these services? I wouldn’t subscribe just for Gmail or Microsoft 365 mail, because it’s easy and free to use IMAP to store a copy of all your email on your Mac and then back your email up with the rest of your data. As for other cloud-based data, it depends on how heavily you use the services and how important your data is. I use Google Docs and similar web apps only occasionally, and the data I store there isn’t important enough to me to pay for an extra backup. However, if you store crucial data only in the cloud, a cloud-to-cloud or cloud-to-local backup service may be a smart investment.
Back Up While on the Road
It’s relatively easy to back up when you’re at home or at the office: you can set up a system that copies data from one or more computers to local or network drives and that stores it automatically. But when you’re away from your usual equipment, backups become more difficult.
When traveling with a laptop, you face two main questions:
Do you back up to local media (an external SSD or hard drive, say) or use the internet to back up to a remote location?
If you do choose to back up remotely, what’s the best way to do so safely and efficiently?
Backing up your laptop directly to a hard drive, SSD, or flash drive is invariably quicker than backing up over the internet. You also avoid any worries about sensitive data being intercepted in transit, and you have a handy copy of your data available for instant restoration if you need it. On the other hand, if your laptop and its accessories are stolen, left in a taxi, or otherwise lost, you’re likely to lose all your backups too. So, a word to the wise: if you choose to keep your backups with you, at least keep them separate from your computer—and make sure they’re encrypted.
Local backups are best for people who generate large volumes of data—videos, for example. If you create several gigabytes of new files every day while away, backing up remotely might be too time-consuming. A local backup is also the only good option if you’re traveling somewhere without high-speed internet access.
On the other hand, if you generate only a modest amount of data on the road and fast internet access is available (especially if it’s free fast internet access!), backing up remotely is an excellent option, as all your data is safely offsite. Again, be sure to use an encrypted connection or backup software that encrypts the files before they’re sent over the internet, because otherwise you run a slight risk that a hacker could intercept your private data while it’s in transit.
Local Backups on the Road
Compact, bus-powered SSDs with Thunderbolt 3 or 4 or USB4 interfaces are becoming less expensive, and they may be a good option if you need complete versioned backups or bootable duplicates while on the road. (That’s what I’ve been doing myself in recent years.) If that’s what you’re looking for, you should generally find an SSD with at least as much capacity as your laptop’s internal storage. And remember, for bootable duplicates of an M-series Mac, you’ll want a Thunderbolt 3 or 4 drive.
On the other hand, when your concern is to maintain backups of just the files you’re actively working on (as might be the case if you’ll do full backups when you return home or to the office), you have more flexibility in choosing storage media, since massive capacity is unnecessary.
USB flash drives are ubiquitous, tiny, and inexpensive at modest capacities, so they make a good choice for backups on the road. Ditto for SD cards, which you can use directly in a Mac laptop with a built-in SD card reader, or via a USB adapter otherwise. If you have only a few gigabytes to back up, flash drives and SD cards are quite handy.
If you use a flash drive or SD card, keep these tips in mind:
To save time and media while traveling, back up only your most important files—specifically, those you’ve worked on during your trip. (When in doubt, you can do a Spotlight search in the Finder for just those files modified in, say, the last day.)
If your backup app supports encryption, use it. You wouldn’t want someone who stumbles upon your flash drive to get easy access to any personal information stored in your files.
Yet another option is an external hard drive, which lets you back up (and, if necessary, restore) your entire disk, at the expense of greater bulk and fragility than solid-state media. For ease of transportation, I suggest a bus-powered (no AC adapter required), pocket-sized model. See the online appendixes for suggestions.
Remote Backups on the Road
You can back up your files remotely in any of several different ways, depending on your circumstances and preferences. As I mentioned earlier, though, all these methods presuppose that you have a relatively small amount of data to back up; you’ll likely be constrained by the upstream bandwidth of your internet connection and may also have time constraints that limit how much data you can comfortably back up. Here are some remote backup options:
Internet backup services: For backing up a relatively small amount of data, consider an online backup service. For example, Backblaze or IDrive can back up your laptop’s files to proprietary cloud storage, while Acronis Cyber Protect Home Office, Arq, and several other apps can use cloud storage, local hard drives, or both. For more options, see Use a Cloud Backup Service.
Push or pull backups with home server: If you run third-party backup software on a server at home or the office (see Network Backup Approaches), you may be able to connect to that server remotely, but that’s not as easy as it may sound. Push backups work only if you can mount your backup server’s volumes remotely; pull backups work only if your server can mount your laptop’s volume remotely. Sometimes this remote mounting is possible, but often not; your firewall at home must enable access to the necessary ports, and the ISP providing your remote access must permit file-sharing access over their network. You also run a risk that your files may be intercepted in transit by a hacker, unless you take extra steps to encrypt the network link between your laptop and your server.
Client-server backups with home server: Client-server backup software, such as Retrospect, normally polls only the local network for available clients. In some cases, you can manually enter an IP address for a computer outside your local network. However, if you’re traveling and don’t know what IP address you’ll have at any given time, this method is problematic. A possible solution is to use a dynamic DNS service, such as the one provided by easyDNS, to assign your laptop a domain name whose IP address changes as needed, and then enter that domain name in your backup software. Although various other techniques (and third-party networking tools) sometimes allow remote file sharing, they’re less likely to work with client-server setups.
Back Up an iOS or iPadOS Device
This book is about backing up your Mac, but many Mac users are also iOS or iPadOS users, and I’ve had requests to say a few words here about backing up those devices.
Even though iOS and iPadOS devices contain data that’s every bit as valuable as what’s on your Mac, they follow a much different model for both data storage and backups. Here are the key points you should be aware of:
Most iOS/iPadOS data is also stored in the cloud. Even if you never explicitly back up your mobile device in any way, the majority of iOS/iPadOS apps store their data in the cloud (in one form or another), meaning that even if your device were stolen or destroyed, it would be possible to retrieve your data (for example, using a new device). This is true, of course, for data such as calendars, contacts, email, and reminders: when you connect to an online account such as iCloud, Google, or Exchange, your device stores a copy of this personal data—but the original is in the cloud.
Many other apps, both from Apple and from third parties, also use cloud storage or syncing of one sort or another, at least optionally. Some of them use iCloud Drive; others use Dropbox, another cloud storage provider, or a proprietary service run by the app’s developer. In any case, apps that store data locally only on your iOS/iPadOS device are relatively rare. Although the copy of the data in the cloud isn’t exactly a backup as I define it in this book, it can serve much the same purpose, at least to the extent that it protects you against the loss of your device.
Restoring from iOS/iPadOS backups is (usually) all or nothing. The previous point notwithstanding, if you want to back up all the data on your device, including anything you’ve opted to store locally plus all your apps and settings, you can do so (see the next bullet). But you won’t find third-party backup apps for iOS/iPadOS that work the same way macOS backup apps do, and although you can disable backups of individual apps or delete the entire backup of a single device (in Settings > your name > iCloud > Manage Storage > Backups > device name), that’s the extent of control Apple gives you. More significantly, if you lose data and need to restore a backup, you must normally restore everything—that is, wipe everything off your device, reinstall the operating system, and restore all your data from an iCloud or Finder/iTunes backup. Apple provides no way to restore individual files from a backup.
You have two (or maybe three) backup options. Apple offers two approaches to the all-or-nothing backup. One way is to use iCloud, which takes just a few taps to set up (go to Settings > your name > iCloud > iCloud Backup and make sure the switch is turned on). With iCloud backups enabled (and as long as your device is locked, connected to Wi-Fi, and attached to a power source), iOS/iPadOS backs up all your data to iCloud once a day. The other option, if you prefer to avoid iCloud, is to back up the data from your mobile device(s) to your Mac using the Finder (in Catalina or later) or iTunes (in Mojave). You can use either a Wi-Fi connection or a USB cable for Finder/iTunes backups; the former is more convenient but the latter is faster. If you do choose a Finder/iTunes backup, be aware that all the data you’re backing up from your iOS/iPadOS device will take up space on your Mac, and thus it will also take up space in your Mac’s backups.
Apple provides complete instructions for setting up iOS/iPadOS backups via either iCloud or the Finder/iTunes in How to back up your iPhone, iPad, and iPod touch, and for restoring backups in Restore your iPhone, iPad, or iPod touch from a backup.
There’s a third option, courtesy of an app called iMazing, that’s a bit more flexible in its approach to local backups, but also suffers from the most serious limitations as a Finder/iTunes backup; see the sidebar What About iMazing? just ahead.
As a reminder (see Back Up Data from the Cloud), storing data in the cloud and backing up to the same cloud service isn’t really smart! So, if you rely on iCloud storage for all the documents on your iOS or iPadOS device and also use iCloud backups exclusively, you’re entirely at the mercy of iCloud. So, I recommend thinking carefully about where your data is stored and choosing a backup destination that’s different from your storage destination.
Back Up Windows Files and Volumes
You can run Windows alongside macOS, using either Apple’s Boot Camp software (which puts the entire Windows installation on a separate partition and works only on Intel-based Macs) or virtualization software such as Parallels Desktop or VMware Fusion (which stores the Windows environment in a special disk image file). Either way, the presence of a second operating system increases the complexity of your backup needs.
If you use Windows only occasionally and don’t store much data on your Windows volume, you might consider forgoing Windows backups altogether. Reinstalling Windows and a few apps (as you might have to do in the case of a disk problem) is annoying but not the end of the world. (And, if you use a cloud sync service such as Dropbox for most of your personal files, you can install the corresponding app and let it sync, eliminating the need to fetch those files from a backup.) However, if your use of Windows is more extensive, read on for instructions on keeping your data safe.
The way you back up your Windows files depends partly on the way in which you’re running Windows and partly on your specific needs. The main consideration is whether you’re using Boot Camp or a virtualization environment.
Boot Camp
Boot Camp was Apple’s official Windows-on-Mac solution for Intel-based Macs. It’s not available on M-series Macs, but if you’re still using Boot Camp on an Intel Mac, you may want to back it up. As far as macOS is concerned, the Windows partition that Boot Camp creates is just another volume, so most Mac backup software can read its files easily. That may lead you to conclude you can simply back up your Windows partition along with your Mac partition using your favorite Mac backup app; however, a few issues arise:
Since your Windows volume must be formatted as NTFS, macOS can read from, but not write to, that volume. This means you can back up your files but not restore them from within macOS—a potentially significant problem.
One way around this problem is to use Microsoft NTFS for Mac by Paragon Software, which transparently allows macOS to read and write NTFS volumes. There’s also the open-source NTFS-3G and its commercial variant, Microsoft NTFS for Mac by Tuxera, both of which are based on MacFUSE from Google Code.
Some backup software, including SuperDuper!, cannot read from Windows partitions at all.
If you rely on Mac software to back up your Windows volume, backups can take place only when you’re running macOS. So if you run Windows under Boot Camp for extended periods of time, your risk of data loss increases.
Even in cases where you can back up the entire contents of your Windows partition while running macOS, a complicated procedure is usually necessary when restoring files to make sure the restored Windows volume is bootable. So, as with duplicating a macOS volume, it’s a job better left to specialized software, in this case software running under Windows.
Therefore, if you’ve decided to back up your Boot Camp volume, you’ll need to develop separate strategies for creating duplicates, versioned backups, or both.
Duplicate a Boot Camp Volume
The easiest way by far to duplicate (and restore) a Boot Camp volume without leaving macOS is to use Winclone, a Mac backup utility specifically designed for that purpose. Winclone is a simple, straightforward app: you choose a source (your Boot Camp volume), click the Image button, and follow the prompts to create a disk image with a copy of all your Boot Camp files; you can store that image anywhere you like, including on your internal disk. You can also restore a Boot Camp volume without rebooting from another drive. Winclone Standard costs $49.99; there’s also the much more expensive Winclone Pro, for enterprise customers.
Alternatively, you can make a bootable duplicate of your Windows volume from within Windows. Very few Windows backup apps offer this capability; one that does is called Casper.
A more common way to back up a Windows installation is called imaging. In Mac terms, creating a Windows system image would be comparable to duplicating one’s entire disk onto a disk image stored on another volume; the disk image itself wouldn’t be bootable, but you could restore it onto a hard drive that then would be. Sometimes, Windows imaging utilities can create incrementally versioned images, such that you can restore your entire disk (although not necessarily individual files) to various past states without requiring multiple complete copies of the whole disk. Imaging software may let you store a single backup on another disk in such a way that you can boot from that disk if you connect it to the same computer, but unlike in macOS, a disk that can boot up one PC can’t necessarily boot another; some imaging utilities can make this happen, but some can’t.
Examples of Windows imaging software include:
Casper (which, as mentioned above, also creates bootable duplicates)
Windows Backup (built into Windows 7 and later, but has far fewer features than the others)
I no longer use Boot Camp (virtualization meets my needs better), and even if I did, my usage would be so light and infrequent that imaging my disk wouldn’t be worth the time and bother. So, I haven’t used any of these apps extensively enough to have much of an opinion other than to say I’d start with a free choice and go from there. However, I do think some variety of versioned backups is a good idea, and I turn to that topic next.
Create Versioned Backups of a Boot Camp Volume
If you want to make versioned backups of some or all your Windows files, you can do so either from macOS—after a reboot, naturally—or from within Windows.
Versioned Boot Camp Backups Under macOS
It may be possible to use Mac backup software to make versioned backups of your Boot Camp volume. Your Mac backup software should be able to see and to back up Windows files, but you’ll be unable to restore them from within macOS unless you’ve also installed Microsoft NTFS for Mac or similar software (as described previously).
In any case, remember that because these methods depend on macOS software, which can’t run until you reboot in macOS, your files won’t be backed up while you’re using Windows.
Yet another option exists, and although it might involve changes to your workflow, I think it’s the simplest approach. If you install MacDrive under Windows, you can mount your Mac (Mac OS Extended or APFS) volume and read and write files on it directly, just as though it were a regular Windows volume. So, if you do this and then ensure that you always save the Windows files that you want to back up on your Mac volume, they’ll always be backed up with the rest of your Mac files when your Mac backup software runs.
Versioned Boot Camp Backups Under Windows
If you run Windows under Boot Camp frequently, and create or modify lots of files there, then making versioned backups of your Windows files is important for the same reason as doing so for your Mac files.
You can do this in many ways, but I suggest choosing one of three main approaches (listed here in the order I think you should consider them):
Use a cloud-based sync service with versioning support. If the files you’re creating in Windows are mostly on the small side, you could store them in a folder that you sync with a service like Dropbox or SugarSync (see the sidebar What About Cloud Storage and Syncing Services?). They would be automatically synced to the cloud, with multiple versions stored there, and you would avoid having to do any extra work to keep the files backed up. On the minus side, this would work only for a limited set of files—not for every file on your Windows volume.
Run cross-platform, network backup software. If I were setting up versioned backups for my own Boot Camp volume, I’d use Backblaze. The Windows version is almost identical to the Mac version, and I can use my existing account (although I’d have to pay for an additional subscription). If you’re already doing network backups with Retrospect, that’s another good choice—but keep in mind that the computer functioning as your backup server can’t be the same Mac that’s running Boot Camp. Other apps could work too, but all things being equal I like the idea of using the same software and storage media for backups on all my computers.
Run Windows-only backup software. There are oodles of Windows-only backup apps—more even than on the Mac (and that’s saying something). I have no personal experience with backup software that runs only on Windows, but I’ve read good things about StorageCraft’s ShadowProtect Desktop, which goes beyond mere imaging to offer the sort of detailed control over versioned backups that my favorite Mac backup apps do.
Virtualization Software
If you use virtualization software such as Parallels Desktop or VMware Fusion, your Windows files live on a special disk image that appears as a regular volume in Windows. Your existing Mac backup software can copy that disk image, making what amounts to a bootable duplicate of your virtual machine—but read on to learn about some potential pitfalls of doing so. You can also use any of several techniques to make versioned backups of individual files and folders inside your virtual machine, either in macOS or from within Windows.
Duplicate a Virtual Machine
Since a virtual machine disk image is, as far as macOS is concerned, merely a file (or, in some cases, a series of files), the easiest way to back them up is simply to ensure that your Mac backup software copies them along with the rest of your documents. In other words, whether you create a duplicate or a versioned backup of your Mac data, you still end up with a bootable duplicate of your Windows virtual machine.
But there’s a catch: the disk image is usually quite large—often in the tens of gigabytes—and simply running Windows modifies the image. That creates a problem for any backup software that does file-by-file incremental updates (as Time Machine does, for example), because it will consider the whole file to have changed each time. Adding these disk images to versioned backups will rapidly chew up disk space and make backups take much longer.
You can solve this problem in any of several ways:
Create snapshots. Both Parallels and Fusion let you take snapshots of your virtual machine’s current state, so you can roll back to that state at a future time if the need arises. Taking a snapshot saves the largest portion of your virtual disk in a read-only state, so that as you continue to use the virtual machine in the future, the changes are stored in smaller chunks that are quicker to back up. In Parallels, you can enable a comparable feature called SmartGuard: with a virtual machine running, choose Actions > Configure > Backup and select SmartGuard; then click Details and specify a schedule and other settings. In Fusion, you should also turn on AutoProtect to create new snapshots automatically on a schedule: choose Virtual Machine > Snapshots, click AutoProtect Settings, set AutoProtect to On, and click Done.
Use backup software that supports delta encoding. If your backup software copies only the changed portions of files, rather than entire files (see Delta Encoding), you needn’t worry that you’ll have to copy 20 GB of data for every hour that you use Windows.
Back up virtual machines separately. You can exclude your virtual machines from your regular versioned backups and then set up a separate backup, just for the virtual machines, that you run manually as needed—perhaps configuring your software to keep only a limited number of backed-up versions in order to save space.
If your Mac backup software creates versioned backups (whether they’re file-based or they use delta encoding), an interesting consequence of backing up a virtual machine is that the distinction between a bootable duplicate and a versioned backup blurs. You have, in effect, a versioned bootable duplicate: you can return your entire virtual machine to its state at any previous time when a backup ran, although you can’t restore individual files or folders within your virtual machine to earlier states independently. If that’s important to you—as it well may be—read on for how to create versioned backups of files and folders from your Windows virtual machine.
Create Versioned Virtual Machine Backups
Whatever the benefits of backing up an entire virtual machine, one downside is that Mac backup software can’t normally see into your Windows volume to back up and restore individual files and folders. If you spend a lot of time creating and modifying files in Windows, it may be important to have frequent versioned backups of your Windows data rather than wait until you can pause your virtual machine to perform a full backup.
You can create versioned backups of your Windows data in any of several different ways, but I suggest trying one of the first two suggestions that follow if feasible, because they’ll make your life easier:
Use a shared macOS folder. Both Parallels Desktop and VMware Fusion let you set up folders from your Mac (or even your entire Mac drive) so that you can access them from within Windows. So, you could use a shared macOS folder to save the Windows files you create and modify, and simply have your Mac backup software include that folder in your backups.
Use a shared Windows folder. This is the flip side of the previous item. Virtualization software can share folders (such as My Documents) from Windows so that they’re available in macOS—as long as your virtual machine is running. Do that, and your existing Mac backup software can access your Windows data directly.
Back up from within Windows. Use any of the options noted earlier in Versioned Boot Camp Backups Under Windows: sync your data to the cloud with a service that supports versioning (such as Dropbox or SugarSync); use cross-platform, network-based backup software such as Backblaze or Retrospect; or run your favorite conventional Windows backup app. Of these, my inclination would be to install Backblaze.