Superblock options on OS X

How to use TestDisk to recover lost partition
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Joined: 02 Oct 2016, 08:56

Superblock options on OS X

#1 Post by scottl31 » 02 Oct 2016, 09:22


My main system is 10.6, but I have a 10.8 install on a 320GB USB drive. I was booted to that to download sierra and create a bootable USB sierra installer. But in the software, I had the 10.6 drive (named MacMini) selected by mistake when I hit create. I hit force quit when I realized what was happening. It's a 100GB partition with 52GB of apps and system etc. Now it only has 5GB on it and it is named "Install macOS Sierra" but Testdisk actually sees it as MacMini, which seems great to me. But I can't seem to recover this.

When I try write partition, it says Partition: Write error.

So I thought maybe I need superblock, but don't want to do the wrong thing.

So what is the difference between [Org. BS ] and [Backup BS]?

Here is what I have on that screen:

Disk /dev/rdisk0 - 256 GB / 238 GiB - 500118192 sectors (RO)
Partition Start End Size in sectors
2 P Mac HFS 409640 197007831 196598192 [MacMini]

Volume header

Backup volume header

Sectors are not identical.

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Re: Superblock options on OS X

#2 Post by cgrenier » 03 Oct 2016, 06:01

The partition /dev/disk0s1 is probably mounted. You need to umount it before running testdisk, otherwise only read-only access to this disk will be possible. ... -mac-os-x/
If using the Backup Superblock doesn't recover your files, try PhotoRec.

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Re: Superblock options on OS X

#3 Post by scottl31 » 03 Oct 2016, 06:50

I figured out that about it being mounted.

But which superblock option? [Org. BS ] or [Backup BS]?


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Re: Superblock options on OS X

#4 Post by scottl31 » 04 Oct 2016, 21:35

Sorry to bother everyone, but I'm close to reformatting and suffering my loss, but want to try the superblock first. I guess I have a 50% chance of choosing the right option as I assume the superblock overwrites the whole volume.

Anyway, does anyone know which superblock option might get back my drive/files to what was there before I erased it by mistake? If I can't get everything back, I just want my entourage 2008 Database file and I'd be happy.

So which superblock option is likely to help me? [Org. BS ] or [Backup BS]?


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Re: Superblock options on OS X

#5 Post by ac2334 » 13 Jan 2019, 08:29

How are questions like this left unanswered - people are coming here for help

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