Partition disk disappeared

[Mr.Molars]

Hi everyone! I am new here,sorry if I should not be posting this here, tried to look for the thread but my level of knowledge is quite limited and I am not sure if I am looking in the right spot.
The thing is my partition disk disappeared after changing in my mac the startup disk.
I had macintosh disk and a partition of it called HDD. When I restarted my computer using Macintosh disk, HDD disappeared and I am not able to use any file in it. I have tried downloading 'stellar data recovery' and 'Easus'. HDD appears instantly when i hit the scan button but of course when i click on recover it asks me to pay.
Is this the only way to recover this disk?
Can someone explain to me why did this happened?
Any suggestions?

Thanks in advance!!

 

[hobowankenobi]

I assume you did this...but to be sure, what does Disk Utility show you? Did you try using DU First Aid yet?

Is this a partition on your single internal drive, or a different drive?

What version of the OS, and what file format (HFS+, APFS...or something else)?

 

[Mr.Molars]

Hi, Thanks for replying,

Disk utility only shows the Macintosh disk. Partition is on my single internal drive (macintosh disk) and my OS is 10.9.5
All this started when I tried to update it to Catalina. For whatever reason it installed it on the partition (probably I pressed something I shouldnt have) So if I used as startup HDD (the one that has now disappeared) it had Catalina and when I restarted with Macintosh (the main one) it went back to 10.9.5.
File format I believe it was APFS

Thanks!

 

[hobowankenobi]

OK.

This is tricky...because Apple made it that way. When you install 10.15, it automatically converts the file system of that drive (or partition) to APFS. And...HFS+ (the legacy file system) doesn't play so nice with APFS.

And Disk Utility from an older OS that does not support APFS won't be able to help you with the newer file system, or the partitioin it is on.

For giggles, you might try rebooting and immediately hold down the Option key. Do you see both boot volumes at boot?

You could also try booting to Internet Recovery mode (Shift-Option-Command-R) and see if Utilities there shows the APFS partition, and may be able to diagnose/repair it....depending on the version you get, based on your machine and perhaps teh detected or supported OS (tricky!)

 

[Mr.Molars]

OK.

This is tricky...because Apple made it that way. When you install 10.15, it automatically converts the file system of that drive (or partition) to APFS. And...HFS+ (the legacy file system) doesn't play so nice with APFS.

And Disk Utility from an older OS that does not support APFS won't be able to help you with the newer file system, or the partitioin it is on.

For giggles, you might try rebooting and immediately hold down the Option key. Do you see both boot volumes at boot?

You could also try booting to Internet Recovery mode (Shift-Option-Command-R) and see if Utilities there shows the APFS partition, and may be able to diagnose/repair it....depending on the version you get, based on your machine and perhaps teh detected or supported OS (tricky!)

Hey!! Thank you for those options. Now when restarting and pressing the option key it appears the partition. So i selected it and have the data as it was 2 days ago.
The thing is that now it is still working as before: it looks as if I was working in 2 different computers. When I choose HDD (the partition disk you helped me recover) I have some documents, Catalina OS, apps, and then in Macintosh I still have the version 10.9.5
In Macintosh I can't use the apps or files I have in HDD, and in HDD I can use Macintosh files and apps only if I search for them in finder.

Any suggestions on how to solve this? Should I try to install Catalina in Macintosh? Will that solve the problem? Did I explain myself clearly? Thanks!

 

[Fishrrman]

Do you have a backup of any kind?

Something to try (no promises).
Reboot to INTERNET recovery (NOT to the recovery partition) using this key combo at boot:
command-OPTION-R
(you'll need your wifi password if you connect via wifi)

When you get to the utilities menu, open disk utility.
Go to the view menu and choose "show all devices" (if you DO NOT SEE this option, don't worry about it)
Now look on the left -- you should see the internal drive and all partitions.
I would click on each partition, then click the "first aid" button above, run that, and see if it helps.

One other thing (I realize you're learning this "the hard way"):
One DOES NOT do a major upgrade UNLESS one has created a bootable cloned backup of one's drive beforehand using either CarbonCopyCloner or SuperDuper.
Then, if things go wrong (as they have with you), it becomes EASY to "get back, get back, get back to where you once belonged".
No backup -- not so easy.

 

[Mr.Molars]

Do you have a backup of any kind?

Something to try (no promises).
Reboot to INTERNET recovery (NOT to the recovery partition) using this key combo at boot:
command-OPTION-R
(you'll need your wifi password if you connect via wifi)

When you get to the utilities menu, open disk utility.
Go to the view menu and choose "show all devices" (if you DO NOT SEE this option, don't worry about it)
Now look on the left -- you should see the internal drive and all partitions.
I would click on each partition, then click the "first aid" button above, run that, and see if it helps.

One other thing (I realize you're learning this "the hard way"):
One DOES NOT do a major upgrade UNLESS one has created a bootable cloned backup of one's drive beforehand using either CarbonCopyCloner or SuperDuper.
Then, if things go wrong (as they have with you), it becomes EASY to "get back, get back, get back to where you once belonged".
No backup -- not so easy.

Thanks but it didn't work... Yes, you are right about the backups, didnt think it through, it had never given me any trouble so didn't even consider....
Thanks for The Beatles reference, at least it cheered me up!!!

I am thinking of installing catalina in the main Macintosh one, do you think that might "help"?

 

[hobowankenobi]

The challenge is....Apple turned a corner when they rolled out a new file system. It doesn't play nice with the old one.

They expect a user to upgrade, and not look back.

If it were me (and I wanted to retain both OSes for old software, or some other reason): I would clone the 10.9 partition over to an external (formatted HFS+). Boot to it, be sure it works as expected. Once tested, I would simply delete the 10.9 partition. Let the internal drive be single, APFS partition. Simple.

That's assuming you wan to move forward, and only use the 10.9 OS occasionally. You can keep in on shelf, but plug it in and boot to it any time.

And yes, because this is tricky, and a bit of a mine field, backups are even more important before proceeding.

 

[DeltaMac]

No one, so far, has mentioned why your HDD drive is lost when you boot to the macintosh drive.
Here's why: the macintosh drive boots you to 10.9.5 (Mavericks), which does not know what APFS is, cannot see any drive with that format, doesn't give you any access to the HDD drive. It is totally gone - until you boot to the HDD. Even Disk Utility won't show it, other than a generic drive with nothing more than a drive number of some kind (like disk0s3, or something like that) Your 10.9 system is no help at all. But your HDD system appears when you do the Option-boot.
And -- you can then see all your files on the 10.9 macintosh drive.
Try the tip from hobowankenobi - a good backup of the macintosh drive to an external drive. That should work for you.
And, after making that external backup, delete that 10.9 partition, so you don't accidentally boot to that old system.

 

[hobowankenobi]

Delta is right. I did not make it clear...the old file system simply cannot see or interact with the new one.