Drive Letter assignments shifted

[Dr. Dos]

I have four independent powered USB drives hung-off my computer via
powered hubs. With partitions, there are 6 (virtual?) drives.
Additionally, there is usually one usb flash drive connected.
Today, all the drives dropped down one letter F
to G, G to H, etc., and the flash drive took F (it usually is L).
Regardless of whether the flash drive is plugged in, or not, these drop
downed assignments persist. Rebooting does not change this.

Multiple questions:
How/why do drive letters persist even when removed from the system? (I
travel and "j" drive always was id'd as j even if f, g, h and i were 500
miles away). The drive volume labels are names, not letters.
Is there a way to hold letter designations steady? The reason is my
backup program backs up to these drives and always has a letter
designation associated with each drive volume name. I think the program
gets lost when Backup0(f) becomes Backup0(g), etc. That appears to be
the case today (backup failed because f could not be found).

Sniffing the registry for hints was not illuminating.

 

[Uwe Sieber]

Multiple questions:
How/why do drive letters persist even when removed from the system?

You can change the drive letter assignments in the Windows
Disk Management (Start -> Run -> diskmgmt.msc).

Windows saves letter assignments, but exactely one assigment
per letter only.
Sample: Drive1 is connected and you assign letter X. Then you
disconnect it. When you attach it again it gets letter X again
because Windows saved this assignment. Disconnect it again,
attach Drive2 and assign letter X, detach it and attach
Drive1 again. Drive1 get the the first free local letter now
beause the previous assingment has been superseded by Drive2.

Therefore there is always a rivalry for the first availlable
local letter. Maybe you had the flash drive attached while
booting up and Windows assinged F because it's the first
availlable letter and the other USB drive came a bit later
when Windows enumerated the drives.

The best solution is to assign high letters for USB drives,
far away from the first availlable one.


Greetings from Germany

Uwe

 

[Dr. Dos]

You can change the drive letter assignments in the Windows
Disk Management (Start -> Run -> diskmgmt.msc).

Windows saves letter assignments, but exactely one assigment
per letter only.
Sample: Drive1 is connected and you assign letter X. Then you
disconnect it. When you attach it again it gets letter X again
because Windows saved this assignment. Disconnect it again,
attach Drive2 and assign letter X, detach it and attach
Drive1 again. Drive1 get the the first free local letter now
beause the previous assingment has been superseded by Drive2.

Therefore there is always a rivalry for the first availlable
local letter. Maybe you had the flash drive attached while
booting up and Windows assinged F because it's the first
availlable letter and the other USB drive came a bit later
when Windows enumerated the drives.

The best solution is to assign high letters for USB drives,
far away from the first availlable one.


Greetings from Germany

Uwe

bitte