Mapped drives suddenly disappear and not auto mapping, but manually is fine

James Edmonds 821

Hi,

We've had a number of users who have started to report that their main mapped drive to our central file share disappears from their profile.

Restarting, signing out and back in, and gpupdate fail to remap the drive and there are no errors in event viewer indicating any issue.
Gpresult shows it should be successfully applying without error.

If I get the users to manually map the drive, it firstly says S is already mapped to that share, but when completing the process and accepting the warning that S is already mapped, it succeeds and shows back up in Windows Explorer.

Can anyone offer any thoughts or input as to why the mapped drive may have suddenly started exhibiting this behaviour, and how to further diagnose, given that the manual mapping works perfectly?

Thanks
James

Stefan 1 Reputation point

2022-06-02T11:39:48.41+00:00

A work around is to restart the process "Windows Explorer" in the Task Manager. After that all drives reappear.
James Edmonds 821 Reputation points

2022-06-13T10:13:30.947+00:00

Touch wood, I've not had this issue again since for any of our users.

I will give this a go if and when it happens again though, and advise if it helps.

Many thanks
James
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3 answers

Limitless Technology 39,671 Reputation points

2022-01-21T22:05:30.32+00:00

Hello @James Edmonds

It is a very common scenario when the network is not yet ready to connect and successfully map the drive, but it is already configured for the system. Thus saying that it is already mapped, and when retrying, it appears.

Enable the policy: "Always wait for the network at computer startup and logon" located under Computer Configuration -- Policies -- Administrative Templates -- System -- Logon. This might resolve your drive mapping issue.

Hope this helps with your query,

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James Edmonds 821 Reputation points

2022-01-22T01:38:35.713+00:00

Sadly, this issue is happening whilst users are logged in, not at login time. The user will be actively working on a file in the drive, and it will disappear whilst logged in.
Equally, running gpupdate /force in the user's active session with a working network connection, it does not recreate the drive map.

Could it possibly be related to the recent KB5009566 troublesome update?
I don't see anything listed under known issues for it, but wonder if maybe somehow related? I will check my affected users' machines to see if recently installed.

Thanks
James

James Edmonds 821 Reputation points

2022-01-28T15:06:49.487+00:00

Might you have any other thoughts please, as this issue is still impacting a specific small subset of users whilst actively logged in.

Thanks
James
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Philippe Levesque 5,801 Reputation points

2022-01-21T15:15:42.353+00:00

Hi

Do you map your drive via GPP ? Please try in replace mode, and click the restore option. Make sure Run in logged-on user’s security context (user policy option) is clicked too.
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James Edmonds 821 Reputation points

2022-01-21T15:37:02.257+00:00

Hello,

We do indeed use GPP.

It is already in replace mode with reconnect enabled.

We do not have run in logged-on user's security text ticked, as didn't think it was needed, as it is a user policy setting anyway. I can't see what would cause this to start happening requiring this option to be ticked? Also unclear why Windows still thinks the drive letter is mapped but just not showing it in Explorer.
Do you still think we need to enable this option to resolve this issue? I can try it, but will take some time to confirm if helpful and doesn't feel like the underlying issue.

Many thanks.

James Edmonds 821 Reputation points

2022-01-28T15:07:27.817+00:00

Hi, do you think this setting is still relevant given limited scope of users impacted and that every non-impacted user has the drive map deployed in an identical manner?

Thanks
James
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Gary Nebbett 6,086 Reputation points

2022-02-01T09:45:15.18+00:00

Hello James,

I have investigated a similar problem in the past (I wrote about it at https://gary-nebbett.blogspot.com/2021/06/mapped-network-drive-reconnection.html). The work involved in understanding the behaviour might be disproportionate to the potential benefits (few users impacted, infrequent problem that can be overcome with some effort).

My first question would be: are Offline Files (also known as Client-Side Caching or CSC) configured/used on the share?

The troubleshooting approach would be to use Event Tracing for Windows to capture the behaviour. Ideally, one would capture the problem as it happened (if it was easily reproducible), but capturing what happens once the problem has occurred (during the remedial steps (remapping the drive letter)) might give a few hints.

Gary
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James Edmonds 821 Reputation points

2022-02-01T09:56:06.6+00:00

Hi Gary,

I've never really touched offline files myself, but looks to me like it's in the intermediate mode, where it's enabled but controlled on a per user basis?

I'll have a look at event tracing, but it's not something that can be replicated at will sadly, and just happens randomly for those few users throughout the day.
Touch wood, I don't think it's happened again since I changed the GPP from replace to update. This does mean I lose the ability to remove the map when it falls out of scope, but might have resolved the problem.

I'll continue to monitor and see what I can get from event tracing if it resurfaces.

Cheers
James

Gary Nebbett 6,086 Reputation points

2022-02-01T10:16:14.517+00:00

Hello James,

This is the command that I would use to trace the behaviour during the remedial steps: wpr -start smb.wprp!SMB -filemode (and wpr -stop why.etl to stop the trace).

The command depends on the attached file being saved as smb.wprp (.wprp is the common extension used for Windows Performance Recorder Profile files).

Gary

170201-smbwprp.txt

James Edmonds 821 Reputation points

2022-02-01T10:18:49.947+00:00

Excellent, thanks Gary.

Will report back if we have to give this a go.

Appreciate the advice as always!

James

James Edmonds 821 Reputation points

2022-06-13T10:12:31.983+00:00

It's a bit late in the day to comment now, but I think in the end client side caching was enabled for the share.
We removed our DFS config for the share, and CSC along with it. Not sure if it was resolved at exactly the same time, but had no issues since, so may have been related.

Many thanks
James
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Mapped drives suddenly disappear and not auto mapping, but manually is fine

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