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Minimal Repair so Microsoft stops calling a FAT32 fs "RAW"?

Posted: 04 May 2019, 22:17
by sbpetrack
My problem seems to be very common, but the fix seems MUCH too difficult. So my question is if there is a shorter, less dangerous procedure; and if not, a suggestion for one:)

So the main drive of my Dell Laptop is a 238GB Toshiba NVMe SSD. It's a GPT/UEFI disk with 9 (nine!) partitions, the first one being the EFI system partition (FAT 32 filesystem on it.) The disk dual-boots WIndows and Arch Linux. (The other partitions are used by Windows, ArchLinus, or Dell/Windows Recovery).

Suddenly, Microsoft Windows sees the EFI partition as being RAW, not FAT32. But the partition seems to be just fine. I can mount the partition in Linux and read all files; I took a 'dd' image via testdisk and mounted the resulting file in Windows without trouble. I needed to access this partition from WIndows, unfortunately, because the BCD is there, and I needed to edit it to prevent Microsoft from changing my boot order. In fact, this was a clue: when WIndows wanted to make me miserable, it just went and accessed/modified files; but when *I* wanted to use bcdedit to access those same files to prevent this from happening, Windows tell me "that's a RAW partition, no access possible." In the end, I mounted the partition on a Linux VirtualBox VM, then shared the /EFI folder with the Windows box... And this way Windows mounted the "network share" folder /EFI with no trouble, and I could edit the BCD. Finally, WIndows boots just fine, so it seems that the MS bootmgr also sees that the partiion is FAT32.
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It worries me that WIndows sees the partition as RAW; In a moment when i'm not paying attention I"ll just hit "OK" and accidentally format the disk. I could just reformat the partition and restore a back-up. But I don't want to just nuke away some problem. So I ran testdisk, hoping that there'd be some glitch that could be fixed. As a result, here are my questions:

1. testdisk immediately showed me the current partition table, and it looked perfect to me, with one exception:

> No FAT, NTFS, ext2, JFS, Reiser, cramfs or XFS marker

was reported about the EFI partition. Is this likely to be the problem? That if Windows doesn't see a FAT marker (whatever that is) it will assert that the partition is RAW?

2. Is there some option or setting I can use to ask testdisk to write this "FAT(32) Marker"?
3. As far as I could tell at this point, testdisk had reported the correct current GPT partition structure. But I couldn't write that. I had to start a "quick search" to find partitions.

I believe this scenario -- where MS just decides that some partition has gone RAW, but in fact everything is fine, so all i need is the current table verified correct and then written out (Ideally with the missing FAT or other markers etc. put in place.) -- it's extremely common. Is there some way to do this? As soon as testdisk first presents a GPT, there should be an option to verifiy and write it out. That'd be much safer than what i haev to do today (which is check for partitions , which can take a long time, and then I'd have to manage all the 10s of potential partitions that are found).

So my question here is simply "If I am pleased with the GPT as reported by testdisk when it starts up, is it possible to just say "please verify that table and write it out. No need to do even the quick search."
Perhaps there are other things that the "FAT Markers" which testdisk wouldn't need to read , but would automatically put back in when it writes the table. I believe that this would help many of the people who disks suffer abuse at the hands of WIndows.

4. Finally, returning to what actually exists today: If I **do** go through the whole 'quick check' procedure , and in the end reconstruct the correct partition table for testdisk to write out will it in fact write out these (FAT and other) "Markers", so that MS will (once again) see the disk as FAT32?

THank you very much.

Re: Minimal Repair so Microsoft stops calling a FAT32 fs "RAW"?

Posted: 05 May 2019, 08:30
by cgrenier
You can try TestDisk, Advanced, Boot, RebuildBS, List. If you see /EFI, choose Write, confirm, Quit.
After restarting the computer, run "cmd" (right click run as administrator) and "chkdsk /f d:" (replace d: by the correct drive letter).

Re: Minimal Repair so Microsoft stops calling a FAT32 fs "RAW"?

Posted: 05 May 2019, 08:54
by recuperation
sbpetrack wrote: 04 May 2019, 22:17 was reported about the EFI partition. Is this likely to be the problem?
Yes. The specification requires FAT32.
sbpetrack wrote: 04 May 2019, 22:17 2. Is there some option or setting I can use to ask testdisk to write this "FAT(32) Marker"?
No, what you consider as "writing a marker" really means converting the file system to a different type.

Re: Minimal Repair so Microsoft stops calling a FAT32 fs "RAW"?

Posted: 06 May 2019, 00:58
by sbpetrack
You can try TestDisk, Advanced, Boot, RebuildBS, List. If you see /EFI, choose Write, confirm, Quit.
I can follow your instructions up to clicking on "[Advanced]". When I do, there is no menu item called "Boot" -- there is only Type // Image Creation // Quit. I choose "type" and set the type of partition to be FAT32 and then [Proceed]. And NOW I see that there is a menu Item "[Boot] Boot sector Recovery". I choose it, and then i can choose RebuildBS. Once that is finished, I do indeed see the partition files there (I.e. "I see /EFI").

Now i get confused, because your instructions say "choose Write, confirm, Quit". And I don't see "Write". I **do** see a file-picker which lets me back up the entire directory tree of the filesystem on the partition. I do this, and then press Q multiple times to exit test disk.

Should I have seen something which explciitly said "Write" and "confirm"? In any case, on the way exiting testdisk, I see this screen:
Image

Unfortunately, MS still sees the partition as RAW in diskpart. But i see that you tell me to reboot. I will do that now.