Question Disk questions... Active partition, and extra partition on storage drives

[Charlie98]

I recently recombooberated my primary desktop, added an NVMe drive, and swapped some other drives around. Now I'm getting some odd listings on some of the disks...

Basic Windows 10 Disk Management screen... shows all my disks.

Question: Why does G: drive show 'Active' when it is just a USB portable storage drive?

View from Acronis... Nothing really out of the ordinary, but why isn't E: drive labeled as 'HDD Storage 1' as it should?

View from Macrium, which I just installed on a trial basis. A few odd things...

Question: ...again, E: Drive is not labeled, and, worse, there is this mysterious partition, now? Says it's unformatted, but it shouldn't be there, anyway. Interesting that it doesn't appear on either Disk Management, or Acronis.

Question: Although it doesn't show it, Macrium also shows my one portable as 'active' as well.

When I installed Windows 10, I did it from CD, and only the SSD was attached during install, so I don't know why 1) there is a partition on the storage HDD E:, and 2) why my portable is 'active?'

 

[mv2devnull]

AFAIK, "active" (aka "bootable") is one flag in the partition table of a disk. Each disk can have one boot partition (whether it has OS or not). Depends on who/what wrote the partition table.


The "label" and "drive letter" are optional data stored within filesystem. Windows enumerates letters for devices by default, but you can set "none" or specific letter for a filesystem. Then it is stored there. (No idea how a conflict of two identical, explicitly set letters is resolved.)

When you did create filesystems (aka format), you/used program wrote (or didn't) those labels.


The space before "E:" is 128 MB. The partition for "E:" has been either set to begin 128 MB into the drive, or there has been small partition(s) that has been removed. Different tools show unused space differently.

 

[VirtualLarry]

The space before "E:" is 128 MB. The partition for "E:" has been either set to begin 128 MB into the drive, or there has been small partition(s) that has been removed. Different tools show unused space differently.

Could be (or was, if OP deleted it) the "protective MBR". All GPT-formatted / initialized disks in Windows, have a "protective" MBR / partition-table store in disk sector zero.

This is to "protect" the contents of the disk, should you boot or use an OS that is only MBR-aware, and not GPT-aware, that the disk is utilized (up to the max MBR sector count), and not empty (and thus not auto-formatted / partitioned by the primitive MBR-using-only OS).

 

[Charlie98]

All GPT-formatted / initialized disks in Windows, have a "protective" MBR / partition-table store in disk sector zero.

I wondered if that's what it was. I think this is my first GPT-formatted drive...

As an experiment, I wiped both portable drives, and the GPT HDD... reformatting it put that 128MB partition back on, so that makes sense.

I reformatted the USB drive, it is not marked as active now.

Question: Normally, is the only partition marked as active just the reserve partition on the OS drive?

 

[mv2devnull]

I think that the "protective" is something a bit different, as hinted by:

# gdisk -l /dev/sda
GPT fdisk (gdisk) version 0.8.10

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.
Disk /dev/sda: 936640512 sectors, 446.6 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): 8BC4088B-AD20-4B08-9A7D-67C6E0987B91
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 936640478
Partitions will be aligned on 2048-sector boundaries
Total free space is 363708349 sectors (173.4 GiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048          411647   200.0 MiB   EF00  EFI System Partition
   2          411648         2508799   1024.0 MiB  8300  boot7
   3         2508800        69617663   32.0 GiB    8300  local
...

This tool spots both GPT and MBR partition tables (with MBR being the "fake") yet the first partition starts at 1 MiB (sector 2048).
Sector 34 is already usable for partitions, so both partition tables fit into first 17 kiB.
IIRC, GPT has a (copy?) table at the end of disk too.