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drmarshallmd
Posts: 5
Joined: 20 Feb 2022, 19:09

Accidental change of a Mac HFS partition into FAT32

#1 Post by drmarshallmd »

Hi there. I've searched this forum for some time and do not seem to find anything that resembles my situation.

I have a late 2013 macbook pro, with a 1TB ssd. I had a 550GB HFS partition dedicated for my storage of files, videos, and programs.
In an attempt to partition a few GB for a BOOTCAMP partition ( i need to install windows 7 to use with the Riffe machine), i accidentally formatted the entire 550GB drive into a FAT32 partition(It used to be HFS). The whole thing took about 3 seconds and felt rather unpleasant. Now the drive shows up as empty.
I've installed TestDisk and managed to get a scan going. What it finds is the NEW 550GB FAT32 partition, though it still shows the old name(It was called Data1). I am unable to see any of the files, or find the OLD partition, even when i do a deep search.
Something tells me if I restored it from FAT32 back to Apple HFS, it may be helpful. I am not sure, and am afraid to do anymore changes which may compromise recovery of files or recovery of the partition.
Has anyone experienced a similar situation? Any advice would be greatly appreciated.

Thank you for your time

Alexei
Last edited by drmarshallmd on 21 Feb 2022, 02:06, edited 1 time in total.
recuperation
Posts: 3035
Joined: 04 Jan 2019, 09:48
Location: Hannover, Deutschland (Germany, Allemagne)

Re: Accidental change of a Mac exFAT partition into FAT32

#2 Post by recuperation »

drmarshallmd wrote: 20 Feb 2022, 19:34 Hi there. I've searched this forum for some time and do not seem to find anything that resembles my situation.

I have a late 2013 macbook pro, with a 1TB ssd. I had a 550GB partition dedicated for my storage of files, videos, and programs.
In an attempt to partition a few GB for a BOOTCAMP partition ( i need to install windows 7 to use with the Riffe machine), i accidentally formatted the entire 550GB drive into a FAT32 partition(It used to be exFAT). The whole thing took about 3 seconds and felt rather unpleasant.
I don't know if formatting on a macbook pro triggers trimming all sectors of the involved partition on a SSD. That would be bad news. Otherwise it is not possible for a current SSD to delete/overwrite 550GB in 3 seconds.
Now the drive shows up as empty.
I've installed TestDisk and managed to get a scan going. What it finds is the NEW 550GB FAT32 partition. I am unable to see any of the files, or find the OLD partition, even when i do a deep search.
The NEW partition is the OLD partition as formatting only involves writing inside of your partition. If using the p-key "list files" doesn't show you your files use Photorec or any commercial recovery software that is evaluating the remains of your old file system as opposed to Photorec which is a tool of last resort.
Something tells me if I restored it from FAT32 back to Apple APFS, it may be helpful.
What do mean by "restoring", formating? What is the use of an overwritten exFAT filesystem overwritten with an empty FAT32 file system to be overwritten again by APFS? This way you increase the chance of even more data being overwritten.
drmarshallmd
Posts: 5
Joined: 20 Feb 2022, 19:09

Re: Accidental change of a Mac exFAT partition into FAT32

#3 Post by drmarshallmd »

recuperation wrote: 21 Feb 2022, 00:37
drmarshallmd wrote: 20 Feb 2022, 19:34 Hi there. I've searched this forum for some time and do not seem to find anything that resembles my situation.

I have a late 2013 macbook pro, with a 1TB ssd. I had a 550GB partition dedicated for my storage of files, videos, and programs.
In an attempt to partition a few GB for a BOOTCAMP partition ( i need to install windows 7 to use with the Riffe machine), i accidentally formatted the entire 550GB drive into a FAT32 partition(It used to be exFAT). The whole thing took about 3 seconds and felt rather unpleasant.
I don't know if formatting on a macbook pro triggers trimming all sectors of the involved partition on a SSD. That would be bad news. Otherwise it is not possible for a current SSD to delete/overwrite 550GB in 3 seconds.
Now the drive shows up as empty.
I've installed TestDisk and managed to get a scan going. What it finds is the NEW 550GB FAT32 partition. I am unable to see any of the files, or find the OLD partition, even when i do a deep search.
The NEW partition is the OLD partition as formatting only involves writing inside of your partition. If using the p-key "list files" doesn't show you your files use Photorec or any commercial recovery software that is evaluating the remains of your old file system as opposed to Photorec which is a tool of last resort.
Something tells me if I restored it from FAT32 back to Apple APFS, it may be helpful.
What do mean by "restoring", formating? What is the use of an overwritten exFAT filesystem overwritten with an empty FAT32 file system to be overwritten again by APFS? This way you increase the chance of even more data being overwritten.
I am aware that the OLD partition is now the NEW. When i try the list files feature, nothing shows up. I tried using one commercial software so far and it yielded nothing.

When i say "Restoring" i mean repairing the partition table. I've read of some1 doing something similar, where he basically repaired the partition table using TestDisk, and that brought all the data back.
recuperation
Posts: 3035
Joined: 04 Jan 2019, 09:48
Location: Hannover, Deutschland (Germany, Allemagne)

Re: Accidental change of a Mac exFAT partition into FAT32

#4 Post by recuperation »

drmarshallmd wrote: 21 Feb 2022, 02:16 When i say "Restoring" i mean repairing the partition table. I've read of some1 doing something similar, where he basically repaired the partition table using TestDisk, and that brought all the data back.
I wrote:
"The NEW partition is the OLD partition as formatting only involves writing inside of your partition.
That is not true in cases like yours where you are formating using a different file system.
Your operating system will then update the partition table writing an new partition type.
But you can play around with your partition table as you like but that won't bring back the information that you deleted WITHIN your partition when formating it.

Your case is not a case with just a destroyed partition table that can be recreated out of other available information on the drive.
drmarshallmd
Posts: 5
Joined: 20 Feb 2022, 19:09

Re: Accidental change of a Mac exFAT partition into FAT32

#5 Post by drmarshallmd »

recuperation wrote: 22 Feb 2022, 12:48
drmarshallmd wrote: 21 Feb 2022, 02:16 When i say "Restoring" i mean repairing the partition table. I've read of some1 doing something similar, where he basically repaired the partition table using TestDisk, and that brought all the data back.
I wrote:
"The NEW partition is the OLD partition as formatting only involves writing inside of your partition.
That is not true in cases like yours where you are formating using a different file system.
Your operating system will then update the partition table writing an new partition type.
But you can play around with your partition table as you like but that won't bring back the information that you deleted WITHIN your partition when formating it.

Your case is not a case with just a destroyed partition table that can be recreated out of other available information on the drive.
Thank you for explaining this and following up.

If I understand correctly, you are saying that my files are gone, and there is now way of bringing them back? just like my hamster when i was a kid?
recuperation
Posts: 3035
Joined: 04 Jan 2019, 09:48
Location: Hannover, Deutschland (Germany, Allemagne)

Re: Accidental change of a Mac HFS partition into FAT32

#6 Post by recuperation »

I did not say that.
drmarshallmd
Posts: 5
Joined: 20 Feb 2022, 19:09

Re: Accidental change of a Mac HFS partition into FAT32

#7 Post by drmarshallmd »

recuperation wrote: 22 Feb 2022, 21:10 I did not say that.
Do you have any advice on what I could do in order to restore the files?
recuperation
Posts: 3035
Joined: 04 Jan 2019, 09:48
Location: Hannover, Deutschland (Germany, Allemagne)

Re: Accidental change of a Mac HFS partition into FAT32

#8 Post by recuperation »

As I don't know the inner structure of HFS I have no idea to what extent HFS can be dammaged by formating it as FAT32.
Try out Photorec.
Try out all available recovery software for HFS.
I guess there is not that much around compared to Windows.

Otherwise, if necessary, consult some professional recovery lab.
drmarshallmd
Posts: 5
Joined: 20 Feb 2022, 19:09

Re: Accidental change of a Mac HFS partition into FAT32

#9 Post by drmarshallmd »

recuperation wrote: 25 Feb 2022, 00:56 As I don't know the inner structure of HFS I have no idea to what extent HFS can be dammaged by formating it as FAT32.
Try out Photorec.
Try out all available recovery software for HFS.
I guess there is not that much around compared to Windows.

Otherwise, if necessary, consult some professional recovery lab.
Thank you!
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