Windows 10 „Fast Start“ destroyed USB-attached-filesystem

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Windows 10 „Fast Start“ destroyed USB-attached-filesystem

Veeam Logoby Django » Tue Aug 30, 2016 12:30 pm 1 person likes this post

Hello fellow community,

I have daily scheduled Veeam Endpoint Backups and use USB attached HDD as destination. I have two identically USB HDDs 1 TB formatted with NTFS filesystem. Every Monday I swap the USB attached HDD while the system is power off. This strategy was working fine with Windows 7 and VEB for a long time. So let me explain how Windows 10 destroyed the filesystems reproducible:

I upgraded my office computer from Windows 7 to Windows 10 (v. 1511). Veeam Endpoint Backup schedule was running in the background and completed with success. However, Windows has started to report NTFS and chkdsk errors in the windows eventlog. I was wondering what was going wrong? Maybe a defect USB enclosure, HDD or USB port? I always swap the HDDs while the PC has been shut down. Yesterday I did troubleshooting the HDD swap by using the vol and mountvol commands.
Both commands show the volume-GUID/volume-serial. The result was surprising:
Method of swap:
Eject from task bar icon:
Result after swap
volume-id changed, browsing files is correct for new disk.

Method of swap:
Shutdown via start menu, swapping while power off
Result after swap and startup
volume-id did not change, browsing files from disconnected disk still possible (likely cached)

Windows 10 did not dismount the volume during shutdown! What?!?!
The reason is the windows 10 "Fast Startup Feature", which can be compared with the hibernation mode. Please look in this article to find more information about Windows 10 “Fast Startup” and the disadvantages. It is enabled by default on a lot of installations. Now shutdown does not mean shutdown anymore, referring to Walter Glenn the author of the article. (
You can even proof that if you open your command prompt and type in “mountvol [drive letter]: /L“. That command shows you the GUID of the volume, which is unique. Also the task manger is showing a high uptime because a shutdown has not been executed.

So there are two ways to prevent this:
1.You disable the “fast Startup” feature in the power options of windows 10 (procedure is also in the linked article) and swap USB-HDD while PC is shut down.
2.The second option is, you dismount/eject your drive manually every time with the eject option from the task bar icon and swap USB-HDD while the PC is running.

Does anyone else have issues with windows 10 Fast Boot? I recommand to disable "Fast Startup mode" for USB attached backup destinations or removeable media usage.

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Re: Windows 10 „Fast Start“ destroyed USB-attached-filesyste

Veeam Logoby Dima P. » Wed Aug 31, 2016 5:28 pm

Hi Django,

Good read - thanks for posting. By the way, have you tried using the rotated drives feature of VEB in conjunction with Auto eject functionality?
Dima P.
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Re: Windows 10 „Fast Start“ destroyed USB-attached-filesyste

Veeam Logoby rjaworski » Fri Sep 02, 2016 8:58 am


Thanks for posting this, this answers many questions, I just had similar issue with my Dell laptop and Win 8.1 Pro.
In my case, it turned out that Windows hibernation was causing external drive read errors, after disabling it, I am able to continue with incremental backup without running checkdisk or formatting the external drive.
Note: Im using 2TB Fujitsu Deskstar enterprise grade drive put into cheap enclosure.
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Re: Windows 10 „Fast Start“ destroyed USB-attached-filesyste

Veeam Logoby Anguel » Fri Sep 02, 2016 10:55 am

The first thing I do on new Windows installations is to disable fast startup. It is one of Microsoft's most stupid ideas (although there are many of them competing) as it will also disable Wake On LAN that worked perfectly before. Additionally, beware that in Windows 10 fast startup will be auto-reenabled (!) after updates (yes, Microsoft does not stop creating nonsense features / bugs).
For more information please refer to my blog article: ... ndows.html
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