Easy way to have integrated back-up (inside the computer itself), mirrored drive?

Partitioning your single internal storage device and then mirroring each partition is protecting nothing and wearing out your NVMe storage at twice the speed.

Any hardware failure will affect both sides of the mirror. Any software bug will write the error to both sides of the mirror. Any file delete will delete the file on both sides of the mirror. If the Mac gets damaged or stolen, both sides of the mirror are lost to you.

Only a tiny bit better, get a large capacity SD Card, put it in the SD Card slot on the right side of the Macbook Pro, and use Time Machine to backup your internal storage, or a proper backup utility of your choice. DO NOT MIRROR the SD Card, as the speed difference is huge, and you will seriously slow down your Mac if you mirror the SD Card to your internal storage. This still suffers from a stolen Mac loosing both copies, but it does it eliminates the other mirroring issues.

A better solution is external storage. If the Mac sits on your desk 24/7, then a large capacity disk, and Time Machine or other suitable backup utility.

If you are a mobile user, then a NAS with Time Machine support, such as a Synology NAS.

48WineKnot52 wrote:

I had a mirrored drive in my current PC main desk top system. I would like the same on a new 2025 MacBook Pro, M4 , 14 core CPU, 20 core GPU, 16-core Neural, 24GB unified memory & a 1 terabyte drive. Can a mirror drive be added to this config? Worst cast use a 2 Terabyte drive and partition 1 Terabyte as the b/u portion?

Apple laptops are not your choice, given those requirements.

Time Machine with local snapshots enabled provides some local data storage redundancy.

This redundancy is not how you have envisioned your proposed hardware design, though.

Time Machine keeps local snapshot copies of your active storage elsewhere on your internal storage, and also transfers backups to external archival storage whenever connected on specific Wi-Fi networks with NAS servers configured. Duplicate local storage as implemented by Apple with Time Machine can reduce exposure to deletions, app corruptions, and potentially limited protection against partition-level corruptions. Time Machine also takes steps to try to block malware access into backup archives.

This snapshot-based design is not resistant to partition corruptions or to catastrophic controller or storage hardware failures.

As for your preferred RAID hardware design, Apple doesn’t sell laptops with multiple separate internal storage devices. Not in the past ~dozen years. So that’s a not an option with any recent Apple laptops.

Very few vendors of portable computers do offer RAID configurations, and that availability will drive your selection here.

You can get the RAID hardware you want with a Mac mini or Mac Studio using external hardware or software RAID storage, or probably also with a Mac Pro both internal and external.

RAID, however, is most definitely not a backup. As have been mentioned above. Boxes fail, RAID controllers can be buggy or can fail, RAID volumes can get corrupted so with two or even six copies of the same data corruption or malware corruption, and computers can get dropped or dunked or lost or stolen, too.

I am aware of certain enterprise servers that can keep synchronized distributed-shared-write host-based RAID-1 copies active as many as six geographically-dispersed locations across up to 800 kilometers, and those RAID-1 member volumes can then be implemented on RAID hardware at each of the up-to-six sites. That needs big network pipes, and the gear involved is most definitely not portable. And is most definitely not cheap.

R in RAID is for redundant, but RAID is NOT backup!

• Mirrored RAID is used to reduce the time-to-repair after a failure, and to keep physical drive failures from becoming a data disaster. It does not protect from human error, crazy software, or 'just-because' failures.

Executive summary: Most users would be better served using multiple drives to make multiple backups, rather than dedicating multiple drives to RAID arrays.

If you do not have a recent local, disk-based backup, your computer is like a ticking Time bomb. You are only one disk failure, one crazy software, or one "oops" away from losing EVERYTHING! Drives do not last forever. It is not a question of IF it will fail, only WHEN it will fail. In addition, you never know when crazy software or Pilot Error throws away far more than you intended.

If you are using another direct-to-disk backup method that you prefer, and you currently have a recent disk-based backup, that is great. If not, you should consider using Built-in Time Machine. Take steps to acquire an external drive as soon as possible. If you buy one, a drive 2 to 3 times or larger than your boot drive is preferable for long term trouble-free operation. Do not pay extra for a drive that is fast.  (You can get by for a while with a "found" smaller drive if necessary, but it will eventually become annoying).

Attach your external drive and use

System preferences > Time machine ...

... to turn on Time Machine and specify what drive to store your Backups on.  It may ask to initialize the new drive, and that is as expected. APFS format is default format if running MacOS 11 Big Sur or later.

Time machine works quietly and automatically in the background, without interrupting your regular work, and only saves the incremental changes (after the first full backup). Time machine backs up your machine — including every connected drive that is in a Mac compatible format. it can not back up Windows format drives.

Time Machine's "claim to fame" is that it is the backup that gets done. It does not ruin performance of the rest of the computer while doing its backup operations. You do not have to set aside a "Special Time" when you only do backups. When you need it, your Time machine Backup is much more likely to be there.

How to use Time Machine to Backup or Restore your Mac:

Back up your Mac with Time Machine - Apple Support

Time Machine saves, and can re-create, ANY Moment in time for which it still holds backup files.

Example: a user posted that they had installed software that messed up their files. it was installed mid last week. They had done an ordinary restore to recover, but that restored to yesterday, and the problem was still there. 

Readers were able to guide them to Time Machine.APP (not to be confused with Time machine preferences). This allowed them to look at the state of the major folder involved, back in time through each previous backup, until right BEFORE the bad software was added -- mid last week-- and restore as of that moment. They were thrilled.