A NAS for Time Machine and Windows Backup

Why Back Up Your Computers to a NAS

Before the how-to, let's be clear on why a NAS makes such a good home for your backups. It solves the problems that stop most people from backing up at all.

Most folks who lose files did have good intentions. They meant to plug in a drive, or they backed up once and never again. The backup that saves you is the one that happens on its own, without a drive to remember to connect. A NAS is always on and always on the network, so your computer can reach it and back up any time, silently.

• It is always available. No cable to plug in and no drive to find; the NAS is there on the network whenever your computer wants to back up.
• It covers every computer at once. One NAS can hold the backups of every Mac and PC in the house, each kept separate.
• It runs quietly in the background. Backups happen while you work or sleep, with nothing for you to do.
• It keeps history. Both Time Machine and File History keep older versions, so you can go back to how a file was last week.

What You Need Before You Start

A backup to a NAS is not hard to set up, but a few things being in place first makes it go smoothly. Let's gather them.

Nearly every current NAS can act as a backup target for both Macs and Windows. The features have different names on different brands, but the ideas are the same everywhere: a shared folder to hold the backups, an account to control who can write to it, and a setting that welcomes each computer's backup tool. We will use those plain ideas throughout.

• A NAS that is set up, powered on, and visible on your network
• The NAS admin login, so you can create folders and accounts
• Enough free space on the NAS for the backups you plan to keep
• Your computers and the NAS on the same network
• For a Mac, that the NAS supports Time Machine backups over the network

Making a Shared Folder for Backups

Every backup needs a home on the NAS. That home is a shared folder, a folder the NAS offers out over the network for computers to use.

A shared folder is simply a folder on the NAS that other devices are allowed to reach across the network. You create it once, give it a clear name, and decide who is allowed to write into it. Your backups then land inside it. Keeping backups in their own folder keeps them tidy and apart from your everyday files.

• Create a new shared folder. In the NAS settings, find shared folders and add one. A plain name like Backups or TimeMachine works well.
• Decide who can use it. Give the account that will back up permission to read and write in this folder, and no one else.
• Keep it separate from your files. Do not point backups at a folder you also use for documents or photos; give backups their own space.
• Note the network path. The NAS will show the folder's address, something like \\NAS\Backups on Windows. You will need it later.

Time Machine, the Mac's Built-In Backup

Every Mac comes with a backup tool called Time Machine. It is simple, reliable, and happy to back up to a NAS. Here is how it thinks.

Time Machine is Apple's backup feature, built into every Mac. Once you point it at a backup disk, it quietly copies your whole Mac, then keeps copying just what changes. It keeps hourly, daily, and weekly versions for as long as there is room, so you can step back to almost any point in time. A NAS folder can serve as that backup disk over the network.

• It backs up everything. Your files, apps, settings, and the whole system, so a Mac can be restored to just how it was.
• It keeps history. Hourly for a day, daily for a month, weekly beyond that, thinning out older copies as space fills.
• It runs on its own. Once set, it backs up in the background about once an hour whenever the NAS is reachable.
• It can rebuild a whole Mac. From a Time Machine backup you can restore individual files or an entire computer.

Preparing the NAS to Receive Time Machine

For a Mac to back up to the NAS, the NAS has to offer its folder in a way Time Machine understands. This is a couple of switches.

Macs talk to a NAS using a sharing method, a shared language for moving files over the network. The common one today is called SMB. For Time Machine to use a NAS folder, the NAS needs SMB sharing turned on and the folder marked as a Time Machine destination. Both are usually simple toggles in the NAS settings.

• Turn on SMB file sharing. In the NAS network or file-services settings, make sure SMB is enabled. This is how the Mac reaches the folder.
• Enable Time Machine support. Look for a Time Machine or Apple backup option and switch it on for your backups folder.
• Pick the folder Time Machine may use. Point the setting at the shared folder you made, so Macs are allowed to back up there.
• Set a size limit if offered. Many NAS boxes let you cap how much space Time Machine may use, which keeps one Mac from filling the whole NAS.

Pointing Your Mac at the NAS

With the NAS ready, telling the Mac to use it takes just a few clicks. Here is the flow, in plain steps.

If the NAS folder does not show up as a backup disk, open Finder, connect to the NAS by its name or address, and sign in once. That makes the Mac aware of it, and it will then appear in the Time Machine list. This is the most common little snag, and connecting first clears it up.

• 1. Open Time Machine settings. Find Time Machine in System Settings, under General or by searching for it.
• 2. Add a backup disk. Choose to add or select a backup disk. The Mac lists disks it can reach, including NAS folders shared for Time Machine.
• 3. Pick your NAS folder. Select the backups folder on the NAS. If it does not appear, connect to the NAS in Finder first, then try again.
• 4. Enter the account details. Sign in with the NAS account that has permission to write to the folder, and let the Mac remember it.
• 5. Let the first backup run. The Mac starts a full backup. This one takes a while; later backups copy only what changed and are quick.

The Windows Backup Options

Windows has its own built-in ways to back up to a network folder. It helps to know what they are before you pick one.

Windows gives you a couple of built-in tools that can send backups to a NAS folder. They do slightly different jobs. Knowing the difference helps you choose the right one, or use them together.

Setting Up the NAS Folder for Windows

Windows needs to be able to reach and write to a folder on the NAS. Let's make sure that folder is ready and Windows can see it.

On Windows, a folder shared from a NAS appears as a network location, written with two backslashes and the NAS name, like \\NAS\Backups. Before you set up File History, it is worth confirming Windows can open that folder and save a file into it. If it can, the backup will work; if it cannot, we fix the access first.

• Open the folder in File Explorer. In the address bar, type the NAS path such as \\NAS\Backups and press Enter. You should see the folder.
• Sign in when asked. Enter the NAS account that has permission to write there, and tick the box to remember it so Windows reconnects on its own.
• Test that you can write. Try creating a small file in the folder. If it works, Windows has the access the backup needs.
• Map it as a drive if you like. You can map the folder to a drive letter to make it easy to find, though File History does not require it.

Turning On File History to the NAS

Now the payoff on the Windows side: pointing File History at your NAS folder so your files back up on their own.

Once it is on, File History copies your files to the NAS on a schedule and keeps older versions. The first run copies everything and takes a while; after that it copies only what changed. You now have a Windows PC backing itself up to the NAS quietly in the background.

• 1. Open File History settings. Search Windows for File History, or find it under backup settings.
• 2. Choose a network location. Instead of a plugged-in drive, choose to add a network location and enter your NAS folder path.
• 3. Select the NAS folder. Point it at the backups folder you prepared, and sign in with the NAS account if asked.
• 4. Turn File History on. Switch it on so it begins protecting your personal folders to the NAS.
• 5. Adjust what and how often. You can add or remove folders and set how often it backs up and how long it keeps versions.

Backing Up Several Computers to One NAS

One of the best things about a NAS is that every computer in the house can back up to it. The trick is keeping their backups from mixing.

A single NAS can hold the backups of many computers at once. The key is to give each computer its own account and, ideally, its own folder or space limit, so one computer's backup never overwrites or crowds out another's. Set up this way, the whole household is protected in one tidy place.

• Give each computer its own NAS account. Separate logins keep each backup clearly owned and prevent them from stepping on each other.
• Use a folder or a limit per computer. Either a folder each, or a space cap each, so no single computer can swallow all the room.
• Name backups clearly. Sensible folder or account names make it easy to tell whose backup is whose months later.
• Repeat the setup on each machine. Follow the Mac or Windows steps on every computer, pointing each at its own space on the NAS.

How Much Space to Allow

A fair question with a simple answer: a backup that keeps history needs more room than the files themselves. Here is how to size it.

Both Time Machine and File History keep older versions, not just the latest copy. That history is what lets you go back to a file from last week, but it also means the backup grows beyond the size of your current files. A good rule of thumb is to allow room for the data plus a healthy cushion for that history.

• Start from what is used, not the disk size. Look at how much space your files actually take up now, not how big the drive is.
• Allow two to three times that. Roughly double or triple the used space gives comfortable room for version history to build up.
• Add up every computer. If several machines share the NAS, add each one's allowance to see the total the NAS needs.
• Leave the NAS some breathing room. Do not plan to fill the NAS to the brim; drives and backups both work better with space to spare.

Letting It Run Automatically

The whole point of a NAS backup is that you stop thinking about it. Both Mac and Windows tools are built to run on their own.

Once set up, Time Machine backs up roughly every hour, and File History on a schedule you choose. Neither needs you to press anything. Your only job is to make sure the computers can reach the NAS often enough, and to glance now and then that backups are still finishing.

• Keep the NAS reachable. Backups can only run when the computer is on the network with the NAS, so a home network that is always up helps.
• Let laptops connect often. A laptop that is rarely on the home network backs up rarely. Bring it home or onto the network regularly.
• Do not shut everything down nightly. If backups run overnight, the computer and NAS both need to be awake for it to happen.
• Turn on failure alerts if the NAS offers them. Some NAS boxes can warn you if a computer has not backed up in a while.

Checking a Backup Really Worked

This is the page almost everyone skips, and it is the most important one. A backup you have never checked is only a hope in a nice folder.

Backups fail quietly. A setting slips, a laptop stops connecting, a password changes, and the backup simply stops without any fuss. Months later, the day you need it, you discover it stopped long ago. The cure is two small habits: check the date of the last backup, and actually restore a file to prove it comes back.

• Confirm the last backup is recent. On the Mac, Time Machine shows the latest backup time. On Windows, File History shows when it last ran. Glance at these now and then.
• Do a real test restore. Pick a file, restore it from the backup to a new spot, and open it. If it comes back and opens correctly, your backup is genuinely working.
• Repeat after any big change. After a new computer, a new password, or a NAS change, check again that backups still succeed.

Restoring Files on a Mac

Here is the happy part, the reason for all the setup. Getting files back from a Time Machine backup on the NAS is quick and clear.

Time Machine keeps every version it has room for, so you can bring back a file as it was at almost any past moment. You can restore a single file, a whole folder, or, if you ever replace the Mac, everything at once. The NAS just needs to be reachable so Time Machine can read its backup.

• Restore a single file. Open Time Machine, browse back in time to when the file was good, select it, and restore it.
• Restore an earlier version. If a file was changed or damaged, step back to an older version and bring that one back instead.
• Restore a whole folder. Select a folder in Time Machine and restore all of it at once to recover from a bigger mishap.
• Restore an entire Mac. When setting up a new or wiped Mac, choose to restore from a Time Machine backup and point it at the NAS.

Restoring Files on Windows

The Windows side is just as friendly. File History lets you browse back through your files and bring back exactly what you need.

Because File History keeps older versions on the NAS, you are not limited to the latest copy. You can browse a timeline of your folders and restore a file as it was days or weeks ago. This is the everyday hero of backups: undoing a mistake, recovering a deleted file, or getting back an earlier draft.

• Open File History restore. Search Windows for restoring files with File History, which opens a browser of your backed-up folders.
• Browse back in time. Use the arrows to move to an earlier date when the file was the way you want it.
• Pick what to restore. Select a file or folder, then restore it to its original place or to a new one.
• Recover a deleted file. Even files you deleted are there in the history, so you can bring them back.

The NAS Itself Needs a Backup Too

Here is a point people miss once the backups are flowing: the NAS holding all those backups is itself a single box that can be lost.

It feels finished once every computer backs up to the NAS. But now the NAS holds the only copy of all those backups, in one box, in one room. If the NAS is stolen, catches fire, or has a serious failure, every computer's backup goes with it. The backups need a backup, and the time-tested way to think about it is the 3-2-1 rule.

• 3 copies of anything that matters, counting the original.
• 2 different kinds of storage, so one type of failure cannot ruin every copy.
• 1 copy kept off-site, away from the building, so a fire, flood, or theft cannot take them all at once.

Fixing Common Snags

Most backup-to-NAS trouble comes down to a handful of familiar causes. Here they are, with the fix for each.

Almost every backup problem is one of these: the computer cannot reach the folder, cannot sign in, or has run out of room. Work through them in that order and you will clear up the great majority of snags yourself.

Common Mistakes to Avoid

After all the how-to, here are the slip-ups I see most often with NAS backups. Dodge these and you are ahead of nearly everyone.

• Never testing a restore. The big one. An untested backup fails when you need it. Restore a file on purpose, regularly.
• Forgetting the laptop. A laptop rarely on the network rarely backs up. Get it onto the home network often.
• Not remembering the NAS password. Backups quietly stop after a restart. Let the computer remember the credentials.
• Giving the backup too little space. It keeps less history and thins out sooner. Allow two to three times your used space.
• Letting computers mix their backups. Give each its own account and space so they stay separate and fair.
• Treating the NAS as the last word. The NAS itself needs a backup, with one copy off-site. Do not stop at the NAS.

What's in the 27-page PDF

• Setting up a shared folder on the NAS to receive backups
• Backing up a Mac with Time Machine to the NAS
• Backing up a Windows PC with File History to the NAS
• Sending several computers to one NAS without them mixing
• How much space to allow, and how to schedule it hands-off
• Checking a backup really worked, and restoring your files

Why I wrote this

I write these as printable handouts because a guide you can keep in a drawer beats a web page you have to find again. No jargon, no judgment, no rushing. If you'd rather have someone sit beside you and go through it together, that's a flat $99 first visit with the 30-day follow-up included — serving Portage County from Atwater, Ohio. — Bill