1 Topic by Yippee38 (edited by Yippee38 2016-01-09 19:20:08)

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Topic: [SOLVED]New boot record = drive not recognized

I recently bought a new laptop. It came with Win10 on it. I'm not a fan, so I wanted to try to get Windows 7 on it. The difficulty is that it has an NVME SSD drive and Win7 doesn't natively see those. I read that in order to get Windows 7 to recognize it, besides loading the correct drivers (which I have), the NVME disk needs to have a MBR rather than a GPT. So, to try to do that, I did the following (ith the BIOS/UEFI set to Legacy mode and Secure Boot turned off):

Booted into PartedMagic
Ran GParted
Deleted the partitions on the NVME SSD drive and applied changes
I then used GParted to create a new boot record of type msdos
I waited for it to finish, then I exited GParted, and rebooted.
When I rebooted the BIOS/UEFI shows the NVME SSD, but GParted does not show it at all.
fdisk -l shows the other HDD and the USB thumbdrive, but not the NVME drive.
If I use GSmartControl, it shows the drive, but it is listed as "Unknown Device" and shows no information about it.

I don't understand what happened to cause the disk to not be recognized by the OS.  Can anybody give me some insight or offer suggestions on making the drive useable again?

2 Reply by gedakc

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Re: [SOLVED]New boot record = drive not recognized

Does the drive show up as a different device?  You might try "cat /proc/partitions" from GParted Live to see if the drive has been assigned a different device name.

Also if creating an MSDOS partition table did cause the drive not to be shown in GParted, then logic would dictate that reversing this change should make it visible again.  You might try writing a GUID Partition Table (GPT) to the drive again.

3 Reply by Yippee38 (edited by Yippee38 2016-01-09 18:47:18)

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Re: [SOLVED]New boot record = drive not recognized

gedakc wrote:

Does the drive show up as a different device?  You might try "cat /proc/partitions" from GParted Live to see if the drive has been assigned a different device name.

In GSmartControl, I can see the drive.  As I said, it's listed as an "Unknown Model".  When I click on it, it lists the drive (under "Drive Information") as /dev/nvme0n1 (scsi), Unknown model.

"cat /proc/partitions" gives this result:

  7    0       66028  loop0
  7    1      251668  loop1
  8    0   976762584  sda
  8    1   955637760  sda1
  8    2    21123072  sda2
252    0   125034840  svme0n1
  8   16      983040  sdb
  8   17      983008  sdb1

So the drive is recognized by the system, but I think the system doesn't know what to do with it.

Also if creating an MSDOS partition table did cause the drive not to be shown in GParted, then logic would dictate that reversing this change should make it visible again.  You might try writing a GUID Partition Table (GPT) to the drive again.

That's what I thought, but the problem is how to do that.  Gparted doesn't show that device anymore.

I just discovered sgdisk.  Using it, I was able to restore the GPT and create one large FAT partition.  The drive still doesn't show up anywhere though.  fdisk -l doesn't show it.  gParted doesn't show it.  The weird thing is that the drive's SMART data has apparently been wiped.

4 Reply by Yippee38

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Re: [SOLVED]New boot record = drive not recognized

I figured it out.  I was stupid.

I had loaded up a liveCD (thumbdrive, really) of gparted.  That's what I used to change from GPT to MBR.  When I ran into problems, I switched over using a liveCD of PartedMagic.  That's what I was using when I did the stuff in the above message.  Then it hit me that the version of PartedMagic I was using was two years old.  The kernel is old enough that it doesn't have NVME support.  I booted with my gParted live CD and the drive is recognized.

<sigh>

Thanks for your help!  You put me on the right train of thought to figure it out!

5 Reply by gedakc

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Re: [SOLVED]New boot record = drive not recognized

Thanks Yippee38 for reporting back with how your resolved the issue, and for editing the initial post to prefix SOLVED in front of the title.