USB Disk as RAW when plugged in; backup not working

Hi all,

If you see any issues where a newly connected USB disk appears as RAW or does not get assigned a drive letter, this may well solve it.

Go and run diskpart, and type in automount to see what setting is currently being used.

DISKPART> automount
Automatic mounting of new volumes disabled.

If it says that it’s disabled, then we need to enable it.

DISKPART> automount enable
Automatic mounting of new volumes enabled.

Aaron and I had a remote session with David from Sydney – and we found this worked. (Previously the disk wasn’t being mounted or getting a drive letter and was detected as RAW, so someone had to manually assign the drive letter to mount it.)

Note: BackupAssist will assign the drive letter for prepared media, BUT didn’t in this case because the disk appeared as RAW instead of NTFS. Therefore we couldn’t even get to the disk to see if it was a BackupAssist managed disk.

Note: This refers to automatic mounting of NEW volumes. We found that the particular server in question had got “mixed up” with all the drive letter mounting, and the disk was being treated as a new disk. I also cleaned up that server’s mounted device list by doing a “automount scrub” from within Diskpart – but if you do that, each USB disk will be detected as a new disk the first time you plug it in, and get the first available drive letter because this operation will force Windows to forget what disks had been previously plugged in, and their corresponding drive letters.

We also don’t know what would have caused the automount feature to be disabled. However, I have heard of similar behaviours if the Windows Server Backup scheduling wizard is used on that computer.

It is possible to script the diskpart command:

C:\>echo automount enable | diskpart
Microsoft DiskPart version 6.1.7600
Copyright (C) 1999-2008 Microsoft Corporation.
Automatic mounting of new volumes enabled.

I hope this helps everyone!


2 thoughts on “USB Disk as RAW when plugged in; backup not working”

    • Hi Anthony,

      As far as we are aware this command shouldn’t cause any issues regardless of what backup you run it in conjunction with.
      If you do experience issues, then it’s most likely you’ll need to discuss with our support team further.


      BackupAssist Support


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