Reassess Your Backup Strategy
If you’re reading this book for the first time, you may not already have a backup strategy, in which case feel free to skip this chapter for now and move on to Choose Backup Software. But I suggest returning to this chapter in a year or so, by which time you may benefit from its recommendations. If you already have a backup strategy, though, read on to learn the best way to proceed.
Just as I reevaluate my own stance every so often, you too should periodically reassess your backup strategy in light of new information. If you read an earlier incarnation of one of my books and set up your backup system based on what I said years ago, I’d like you to reassess your strategy right now. In any case, put a reminder on your calendar for one year from now to come back and (re)read this chapter, then reassess your strategy again!
I want to begin with a brief “state of the union” look at what has changed in the last two years or so (as I write this in early 2023), and then say a few words about Factors to Reevaluate as you reconsider your backup strategy, both now and every year. Feel free to skim this chapter to see which topics are applicable to you; you might want to jot down a few notes about those topics to help you identify items to concentrate on as you reformulate your backup approach.
What’s New in Mac Backups
Since version 3.1 of Take Control of Backing Up Your Mac in January 2019, a number of things have changed that affect Mac backups. I present the highlights here in a number of different categories.
Bootable Duplicates Present Challenges
For the reasons I enumerated earlier in Why Create Bootable Duplicates (or Not)?, a bunch of factors have conspired recently to make bootable duplicates more difficult to create and use. This is especially so starting with Big Sur, and more pronounced still on the latest Macs with M-series chips.
At the same time, bootable duplicates are arguably much less important than before, thanks to SSDs, the more-reliable APFS file system, and improvements in recovery mode.
For all these reasons, I no longer consider bootable duplicates mandatory. They may be more trouble than they’re worth, and for most of us there are reasonable alternatives (see Alternatives to Bootable Duplicates).
Split Backup Disks Are No Longer Great
For many years, in an effort to save time, effort, and money, my advice was to use a single, large external drive for both versioned backups and bootable duplicates—with one partition for each. (And then, if you wanted to have a secondary backup, you could set up another drive the same way and rotate the drives.) Now, I’m sorry to say that’s no longer a good idea.
To be clear, it is still possible. You can configure either a hard drive or an SSD with two partitions, one for each purpose. In fact, it’s even possible to have both a Mac OS Extended partition and an APFS container (with one or more partitions of its own) on the same disk, should that be an arrangement you find useful. However, I no longer think this is a good idea, because math.
As mentioned just above, bootable duplicates are no longer as important as they once were. But even if you choose to make them, if your Mac has an APFS-formatted startup volume it’s all but pointless to use anything but an SSD to hold the bootable duplicate (see Choose Hard Drives, SSDs, or Both). That means your combined backup disk would have to be an SSD large enough to hold the duplicate (the same size as your internal storage) plus your versioned backup (perhaps two to three times the size of your internal storage; see Versioned Backup Size).
Here’s where the math comes in. If your Mac has a 1 TB internal SSD, you’d need a 4 TB external SSD, the price of which starts at about $250 and goes way up from there. If you have 2 TB of internal storage, you’d need an 8 TB external SSD (since 6 TB models don’t exist); now you’re looking at over $800 for a single backup drive. And so on.
If you have that sort of extra cash—I sure don’t!—knock yourself out. But for ordinary mortals who want to maintain both versioned backups and bootable duplicates, I now think a hard drive for the former and a (smallish) SSD for the latter makes the most sense.
There is, perhaps, one other exception. Because Carbon Copy Cloner can create bootable duplicates and, on APFS-formatted destinations, create APFS snapshots identical to the ones Time Machine makes (see Carbon Copy Cloner Tips), a single backup SSD without any manually created partitions could in fact serve as both a bootable duplicate and a repository for versioned backups.
APFS Evolves Further
In High Sierra, Apple introduced a new file system: Apple File System, or APFS. It supersedes the decades-old Mac OS Extended file system (otherwise known as HFS Plus), with promises of better performance (at least for SSD users), improved data integrity, and greater security (among other virtues). Its reach has now been extended.
Whereas High Sierra used APFS only for SSD startup volumes, Mojave began using it for all startup volumes (including mechanical hard drives and Fusion drives). This change brought the benefits of APFS to more people, but it also came at a cost, as the performance of APFS on mechanical hard drives is quite poor, especially for startup volumes.
APFS has a built-in mechanism for making snapshots that’s somewhat reminiscent of the method certain backup apps use (see APFS Snapshots). Backup apps can tap into this capability, too, and an increasing number of third-party backup apps (including Carbon Copy Cloner, SuperDuper!, ChronoSync, and Acronis Cyber Protect Home Office) have taken advantage of this tool.
Time Machine previously required a backup disk to be formatted as Mac OS Extended (HFS Plus), but starting in Big Sur, Time Machine can also use an APFS-formatted disk as a backup destination. In fact, if you set up a new Time Machine volume from scratch in Big Sur or later, macOS converts it to APFS format automatically. The result should be Time Machine backups that are more compact and more reliable, but this new approach is not without a gotcha or two. (I say more about this later in Decide How to Format Your Partitions.)
Backup App Choices Narrow
At one point several years ago, this book’s online appendixes listed over 100 Mac backup apps. During my most recent update of that list, I eliminated all apps that have been discontinued or simply show no signs of recent development. I also removed anything that won’t run on Catalina. (My reasoning there is that even if an app is still in development, if it hasn’t yet been updated to support at least Catalina, it’s too far behind the times for me to recommend—and its future is doubtful.) Now the list has well under 50 entries, despite the addition of several newcomers.
This isn’t necessarily a bad thing. Creating robust modern Mac backup software is hard. It requires skill, experience, dedication, and a large enough user base to pay for ongoing development. All things being equal, I’d prefer to put my support behind apps with enough history and momentum to convince me they have a future, and frankly I’m happy not to have to think about so many outliers anymore.
T2 Chips Change the Backup Rules
Most Intel-based Mac models introduced in late 2017 or beyond feature an Apple T2 Security Chip. The T2 chip provides a number of security features, and of course I’m all for extra security. However, it also complicates a couple of things when it comes to backups.
With a T2 chip:
You can still make a bootable duplicate, but in order to actually boot from that duplicate, you’ll have to reboot in recovery mode, choose Utilities > Startup Security Utility, and select “Allow booting from external media” under External Boot; for details, see these instructions. (Do not change the Secure Boot setting.) Then restart your Mac.
Prior to Big Sur, it was no problem to create a bootable duplicate of an APFS startup volume onto a backup disk formatted as Mac OS Extended; such a disk is still bootable (keeping in mind the previous point). However, if that Mac OS Extended volume is encrypted (as I generally recommend; see Encryption), a Mac with a T2 chip can’t boot from it. So you must either forgo encryption on your bootable duplicates or format the destination volume as APFS, create the duplicate, boot from the duplicate, and enable FileVault. (Starting in Big Sur, you can’t boot from a Mac OS Extended volume at all, so this point becomes moot.)
M-Series Macs Introduce Challenges
As I detailed in M-Series Mac Changes, the latest Macs based on M-series chips complicate bootable duplicates even more than Macs with T2 chips. For one thing, only Thunderbolt 3 and 4 SSDs are known to work consistently as bootable external devices; USB 3.x SSDs sometimes work and sometimes don’t. And duplicates of Intel Macs running Big Sur or later won’t boot M-series Macs, or vice versa.
External SSDs Approach Affordability
For many editions of this book, I dismissed external SSDs as a sensible choice for backups, because their prices were so outrageous compared to hard drives. Now SSD prices are still much higher, but they’re dropping fast enough and far enough that they’re no longer merely a fringe option for the ultra-rich. As of early 2023, the cost tends to run about $100 per terabyte; I’ve seen 2 TB external drives for under $150 and 4 TB drives for under $250. (For that matter, I’ve seen a 16 TB external SSD for about $3,000—or $187.50 per terabyte. Even larger SSDs exist, up to 100 TB, but at that size the per-terabyte cost goes way back up.)
Obviously, that’s still a huge premium over mechanical hard drives, since you can buy an external, bus-powered, 2.5-inch, 4 TB drive for under $100, or a 5 TB model for under $120. And I’ve seen 3.5-inch, 8 TB USB 3.0 external drives costing less than $140. However, given the extremely poor performance of macOS when running from an APFS-formatted mechanical hard drive, I now recommend using an external SSD for bootable duplicates (see Choose Hard Drives, SSDs, or Both).
Software RAIDs No Longer Work for Boot Volumes
Until recently, it was possible to use a software RAID as a boot volume, but those days are over (see the sidebar RAIDs as Startup Volumes). That puts an end to fancy schemes involving a mirrored RAID with frequently swapped drives functioning as a boot volume with a built-in duplicate, and in fact it means you can no longer store a bootable duplicate on a RAID at all.
Dropbox Kinda Sorta Offers Backups
Since the previous edition of this book was published in 2017, the well-known Dropbox cloud service for syncing and sharing files and folders has added a computer backup feature. On the surface, that sounds like a great way to get the benefits of cloud backup plus the traditional Dropbox sync-and-share capability all in one service. However, this development is not quite the panacea it may seem.
Since the beginning, Dropbox has synced files in a single folder (and its subfolders). The optional computer backup feature lets you back up any or all of the following additional folders to the cloud: Desktop, Documents, Downloads, Music, and Movies. Since most of us keep the majority of our important user-created data in one of those folders, that sounds like a great solution, doesn’t it?
Well, there are a few important details in the fine print:
Dropbox does copy the contents of those folders to the cloud, but it does not sync them across your computers, unlike your conventional Dropbox folder or the iCloud Drive feature that syncs Desktop and Documents folders. Each computer’s folders are kept isolated.
The more data you store in Dropbox, the more likely it is that you’ll be forced to upgrade to a more expensive subscription.
As with files stored in your Dropbox folder itself, Dropbox keeps older versions and deleted files for only 30 days. If you want to extend that to 180 days, you’ll need to buy a Business plan, which is more expensive, and if you want more than 180 days of version history, you’ll have to pay an additional fee on top of that. (An Extended Version History option, formerly available to individuals with Dropbox Plus plans, has been discontinued.)
The only way to restore older versions or deleted files from Dropbox is to use the Dropbox website, and it’s a tedious, one-file-at-a-time operation (unless you want to restore literally every item Dropbox stores to an earlier point in time, all at once).
Using Dropbox—with or without the computer backup feature—does give you some of the benefits of a backup. For example, if for any reason you had to start over from scratch with a new computer or a clean installation of macOS, simply turning on Dropbox could result in many of your important files appearing like magic, without the extra manual step of having to restore them from a backup.
However, the fact that you’re still limited in which folders you can back up and how long you can keep old versions and deleted files, not to mention the cost relative to true online backup services, makes me feel that it’s inadequate as a substitute for conventional versioned backups. (The same can be said of numerous competing services, such as Box, Google Drive, iCloud Drive, Microsoft OneDrive, and SugarSync.)
So, by all means, use Dropbox or a comparable service to your heart’s content. But choose something else for keeping versioned backups—and be sure to back up your Dropbox folder(s) too!
Factors to Reevaluate
The mere fact that technology evolves does not, by itself, mean you need to change anything about your backup system. If everything you set up last year continues to work perfectly now, it’s entirely reasonable to leave well enough alone. However, changes that affect your backups have a way of sneaking up on you slowly, so this is a good time to think about not only new things you can buy but also numerous other factors.
In particular, consider the following questions:
What are your current data and storage media figures? You selected backup methods and storage media based partly on how much data you have to back up (consult Decide on Capacity), but data inevitably grows over time. If you haven’t recently done so, check to see how much data you have to back up. Then make sure your media still has enough breathing room to accommodate your needs over the next year or so—and if not, look into moving up to something with higher capacity. You might also think about whether your data is likely to grow at a faster rate. For example, as our kids grow, the number of photos and videos we record increases dramatically.
Do you have any new equipment? Related to the last point, maybe you’ve purchased a new Mac since last year (including more internal storage, no doubt)—or maybe you’ve upgraded your digital camera, bought a bunch of downloadable movies or TV shows, or added external storage. Whatever the case, take all these into account when calculating how much space you’ll need for backups.
Have you upgraded to a new version of macOS? With more recent versions of macOS, you may find new backup options (products that work only with the new operating systems). You may also find that products you relied on previously are no longer supported.
Are bootable duplicates still worth it? Not many years ago, I would have considered it unthinkable to go without a bootable duplicate, but as I explained earlier in this chapter and in Why Create Bootable Duplicates (or Not)?, times are changing: network-based bootable duplicates are off the table starting with Catalina; any Mac with an SSD formatted using APFS should really store a bootable duplicate, if any, on an external SSD; and updating duplicates can be a bit of a hassle under Big Sur or later. If you can’t remember the last time you actually had to boot from a duplicate to solve a problem, you might want to think about a simpler solution, such as a Data-only duplicate. See Alternatives to Bootable Duplicates.
Are SSDs a better choice now, at least for bootable duplicates? If you’re running Mojave or later on a Mac with an SSD and you’re still using hard drives to store your bootable duplicates, you should reconsider; if you do end up booting from that duplicate in an emergency, it’s likely to be painfully slow. An SSD is a better choice—if you feel (per the previous point) that you still need bootable duplicates at all. (And remember, if you’re making a duplicate of an M-series Mac, you’ll want a Thunderbolt 3 or 4 SSD.) Could you use SSDs for all your local backups? Sure, if you don’t mind the expense.
Should you reformat your backup disk? Separate from the SSD-versus-hard drive question is which file system (Mac OS Extended or APFS) your destination disk(s) should use. In the past, the answer was a no-brainer: always use Mac OS Extended, no matter what. Nowadays, however, different rules apply:
If you’re making a bootable duplicate of a Mac with an APFS startup volume, definitely use APFS on the destination volume too. In Catalina and later, in fact, APFS is obligatory.
For Time Machine disks, APFS is now a better choice if you’re running Big Sur or later on every Mac that will back up to the drive in question and it’s a locally attached (not network) drive (see Decide How to Format Your Partitions). Otherwise, Mac OS Extended is still the right choice, for now.
For other types of versioned backup, APFS provides little benefit, and unless the developer of the backup app you’re using recommends otherwise, I’d stick with Mac OS Extended.
As I explained in Split Backup Disks Are No Longer Great, split volumes (with one partition each for bootable duplicates and versioned backups) are increasingly infeasible. If you intend to keep making bootable duplicates, I suggest getting a separate SSD for those; if you don’t, I suggest reformatting your backup drive to allocate the entire disk for versioned backups.
Are you using Optimized Storage? A group of features collectively called Optimized Storage may have an effect on the way you back up your Mac. Among other capabilities, Optimized Storage lets you move your Desktop and Documents folders to iCloud Drive, and permits macOS to delete local copies of older files that are stored in the cloud (you can download these again later if need be). On the one hand, that could mean less data that you need to include in your versioned backups (see Can You Reduce Your Backup Footprint?). On the other hand, using Optimized Storage makes it all the more important to have backups of the “optimized” data apart from what Apple stores for you.
With Optimized Storage, your Mac won’t tell you when it’s about to delete the local copy of a file (or photo, or whatever) such that the only copy is stored in the cloud. If the local copy wasn’t backed up before this happens, you have just a single copy of that data in the cloud—and if anything happens to that copy, you’re out of luck. So, a word to the wise: make sure your backups (at least your bootable duplicates) include all locations subject to Optimized Storage, and update them frequently.
How old is your media? The physical media on which you store your backups—hard drives, SSDs, optical discs, or whatever—is subject to degradation and data loss over time. If the media you’re currently using is older than a few years or so, strongly consider copying your backups onto fresh new media (and you’ll probably want to upgrade to higher-capacity storage in the process). At the very least, be sure to test your backups from time to time. Hard drives that don’t spin up for years can seize, and SSDs that have been unpowered for years can also lose data.
Are network backups more—or less—viable than before? If you have more computers in your home or office, if their combined storage needs strain individual backup drives, or if you’re tired of moving drives and messing with cables, you might consider switching from local drives to network backups (see Choose Local or Network Backups). The fact that your Mac can function as a Time Machine server with no extra hardware or software (see Use a Mac as a Time Machine Server) may also influence you to embrace network backups. On the other hand, if you’ve been using network backups and found them to be too slow or otherwise unsuitable—and if you have only one or two Macs to back up in the first place—it might be worth switching to individual hard drives or SSDs.
Are cloud backups more—or less—viable than before? Increases in bandwidth and decreases in price may lead you to reconsider cloud backups (see Use a Cloud Backup Service) if you decided against them in the past. Conversely, if you’ve been using online backups and your data has grown at a rate your broadband connection (or budget) can’t keep up with, maybe it’s time to switch services or explore other forms of offsite storage.
Are you relying more heavily on cloud storage and syncing? If you use Dropbox, iCloud Drive, or a similar service for your most important documents, you already have a safety net of sorts, at least for those files. Although it’s not quite the same thing as a real versioned backup (see the sidebar Dropbox Kinda Sorta Offers Backups), it might make restoration easier, leading you to rethink which backup tools you prefer.
Is it finally time to ditch optical media? If you chose optical discs (recordable CDs, DVDs, Blu-ray discs, or whatever) as your storage media years ago, do you feel less secure in that choice knowing that optical technology is rapidly becoming obsolete? Even if your discs remain viable for decades, your next Mac might not have a way to read them, which might make you think twice about continuing to rely on optical media. (For that reason, as well as the sheer effort and expense of using optical media, I’m now actively recommending against it; see Hardware You Should Probably Avoid.)
Are you responsible for protecting more people’s data? If there are more people than before in your household or office and they rely on you to keep their data safe, be sure your current system can scale to accommodate their needs. If not, it may be time to look into client-server backup software (described in Network Backup Approaches) and a NAS with expandable storage (see Consider RAIDs and RAID-Like Tech). Likewise, if your child once used an old laptop for games and web browsing but now uses it to write essays and book reports for school, it’s time to start backing up that laptop.
Has your budget changed? For many of us, income fluctuates from year to year. If you’ve been fortunate enough to earn more money in the last year, perhaps you should consider investing in larger or faster storage devices, or fancier backup software. Conversely, if you feel the need to economize, it might be necessary to scale back on significant recurring expenses, such as high-end online backup services.
Would any of the latest products be a better solution? New and higher-capacity storage devices (see Consider RAIDs and RAID-Like Tech), better online backup options (see Use a Cloud Backup Service), and updated backup software (see Choose Backup Software) may offer solutions to problems that couldn’t be solved easily a year ago, or they may be more affordable than they once were. I’m not one to buy new gadgets just for the sake of keeping up with the latest fads, but if a new product genuinely makes my life simpler or saves me money, I’m all for it.
Is your overall strategy still sound? I hope you took my advice to create versioned backups (see Why Create Versioned Backups?), offsite storage (see Why Store Backups Offsite?), and maybe bootable duplicates (read Why Create Bootable Duplicates (or Not)?). If you chose not to employ one of those strategies in the past, now is a good time to think through the reasons again. (And, per an earlier point, if you’ve been making bootable duplicates, you might think about whether you really want to continue doing so.)
If the time has come to move to new media or even to an entirely different storage method, give some thought to whether you should attempt to migrate your existing backups—for example, move your Time Machine backups from a hard drive onto a server or NAS (see Migrate to a Larger Time Machine Disk)—or start over from scratch. Migrating is not always possible, and the only advantage is that you maintain seamless access to your old backups without having to switch disks. Creating new backups will reduce your storage space requirements and is, overall, a much cleaner approach. But the initial backup will take a while, and your new backup disk won’t contain previously changed or deleted files (so be sure to keep your existing backups safely on hand for a while).