How to create macOS Recovery Partition without reinstalling the macOS itself?

Doesn't reinstall the macOS mean erasing the HD and start again from beginning?

No, not unless you choose to erase it first.

Again with "reinstalling the macOS overtop of an existing macOS partition," does this mean it keep the old files and docs, and only add the Recovery Partition to the Mac HD?

Yes, for the second time.

The installer, do you mean the Mac App Store?

Yes, you download the installer using the App Store App, note it will be a full 10.12.6 installer:

Again, make sure that you quit the installer before you use it, so that you can either copy it or move it outside of Applications folder. Make sure you make a copy and not just an alias. Then when you use the installer, it won't self delete.

Is a recovery partition important?

Mac OS X will not run without a recovery partition.

I suggest that you review how your disk is partitioned. High sierra introduces APFS and it handles partitions differently than HFS+. Mac Mini is generally older disk technology, and favors HFS. High Sierra defaults to APFS, regardless of the technology it is installing. Mac OS Disk Utility lets you manually reset and repair your obviously confused partitions.

Apple Information

Partition a Physical Disk may help you to understand why some parts of your running system cannot recognize Recovery in other parts of your system. I used Apple's information to reset a struggling system to HFS+ from default APFS. After the reset to HFS+ that older Fusion system self-updated to APFS without Recovery problems.

Hope this helps! 😇

https://support.apple.com/en-ca/guide/disk-utility/partition-a-physical-disk-dsk utl14027/mac

You must have a second 'mac' device

You don't need another Mac machine. You need a USB device to hold the macOS installer, that is your second Mac. Every mac owner in a rural area needs a USB installer for each macOS version that is used. Installer good for unlimited Mac machines.

You can use an external drive or secondary partition as a startup disk from which to install the Mac operating system. Place USB installer in USB port. Reboot holding down Option ⌥ key. Select boot device "Install macOS...".

A bootable installer can be useful when you want to install macOS on multiple computers without downloading the installer each time, or without connecting to the Internet.

Download macOS from AppStore or copy from any previous download to Applications folder.

How to create a bootable installer for macOS

https://support.apple.com/en-ca/HT201372

High Sierra installer file: "Install macOS High Sierra.app"

High Sierra... rename USB to MyVolume

sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

Sierra installer file: "Install macOS Sierra.app"

Sierra... rename USB to MyVolume

sudo /Applications/Install\ macOS\ Sierra.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume --applicationpath /Applications/Install\ macOS\ Sierra.app

Insert USB. Triple-click and copy the installer creation scripts above and paste into Terminal

(/Applications/Utilities/Terminal.app). Tap Enter.

That's all. Wado.

andy js, This is my third replay in your thread. Please forgive my exuberance. The thread seemed way off track with no one understanding what a recovery partition is.

Now, You live off the beaten path (the best way to live) so you may have a USB stick to install Sierra 10.12.6. Without a stick you would be forced to upgrade to High Sierra, as that is al that Apple downloads now.

Unfortunately, reinstall is your only option, if your Recovery partition is damaged. It may be that your connection to Apple's server farms is corrupted by rural technology coupled with distance. But would not leave that to chance.

We had doubts about updating our old 2011 Mac Book. Glad we did. You will need a USB to effect repair safely. Also good you have a pair of Apples. Update one and use the other to restore for another attempt if connection fails. Connection can fail in two ways, as you know.

1. Installer download can corrupt downloading.
2. Install can corrupt as data downloaded during install is corrupted.

Understood. Now further, Read carefully my two previous posts. 10.12.6 upgrade to 10.13.2 is painless here in metropolitan Canada. Friends in the hills are still using Lion. That said, the update to APFS is worth those few attempts. Especially if you move files around in Finder.

Finally, there are no issues system-wise with 2-step Sierra HFS to High Sierra HFS+ to High Sierra APFS... personally though, got lost in the increased stability of HFS+ and hosetly just forgot to update my desktop staple diet to APFS until it suddenly occured to me, a few days ago. Anyway, take your time. Downloading installer, a day. Update another day. Keep your personal data safe.

You know, just reinstalling the macOS is a no brainer and really doesn't take that much time. In the time you've spent searching for a solution, you could have completed the install.

P.S., you should be keeping a full backup of your Mac on an external drive.

And if I have reinstall the macOS, that means the next step is to transfer all the files from the latest Time Machine backup?

No, it just reinstalls overtop of your existing partition.

I don't know how fast your Internet connection is, and I don't know the speed or type of your hard drives.

Once the installer downloads to your Applications folder, quit the installer, and make a copy of it or move it out of your Applications folder. That way it won't self delete after you use it.

For me, on a Early 2015 12" Retina MacBook with a 500 GB SSD, reinstalling the macOS overtop of an existing macOS partition takes less than an hour.

Just to note, there probably won't be anymore point updates to Sierra before the release of High Sierra (Can't really speculate though), but many people download the latest full installers and run them over their existing partitions in lieu of using the App Store Software Update feature.

Unfortunately. I have the same problem. My Recovery partition is gone after upgrading Sierra to High Sierra on a Mac Mini... none of the above posts addressed. It was supposed to be a no brainer as in the past.

Exactly. I just re-ran the High Sierra installer and it didn't give me any choices at all. Just went through the automated reinstall process and rebooted me back to square 1. Didn't create the recovery partition.

Steve, reboot your Apple device holding down two keys, Command-R keys together - ⌘-R at the same time. On the setup screen, do not install until you open and use Disk Utility to Repair and Erase your boot partition.

WARNING

I have been told by those who know that if I insist on pushing (forcing) APFS straight onto systems having initial problems with APFS, that is fruitless. For one thing, you will need another backup than Time Machine if you use Airport Extreme Time Capsule, as old HFS backups are not discoverable (wrong partition association) for APFS Time Machine. Apple Engineers will have that Time Machine Recovery sorted out soon. However, sadly our Time Capsule was lost cause after failed APFS update, because even though Capsule Disk Recovery was not found in APFS macOS, it had been "touched" by the APFS installer, rendering it useless to HFS and APFS. Use a good old-fashioned manual folders-with-files backup to any external media. Fortunately we had sticks to copy our files to before the initial APFS install. We used our backup sticks to Restore personal data not stored in iCloud following the Repair-Erase.

Erase your boot partition having initial problems with APFS. YOU MUST manually configure High Sierra to reset Boot Disk to HFS+. Your HFS+ recovery of Recovery should now be complete.

If it's any encouragement, iCloud saved data is not any concern. Also, we found that our gradual graduation of Macs was not necessary. After waiting a month, AppleCare advised to update more directly, first from Sierra to High Sierra HFS+ and then immediately to APFS. Immediate two-step High Sierra Installer HFS+-APFS is the best way forward for all of our Macs, 2017 new and 2011 old.

C.morais, I hope my two posts have answered some questions in the minds of those posting and reading here.

Unfortunately, Apple forums do not run like Wiki. Posters cannot return and correct incorrect post information later. In my first post to thread author, I indicated that High Sierra happily "self-updated". This is incorrect, as I had to manually run High Sierra update by myself. Possible future auto-update aside, I hope that I did not keep anyone from updating now.

Purchase Carbon Copy Cloner. There is a feature for installing a Recovery HD if one is missing on the drive itself.