GPO drive mapping fails and other (logon) problems

We recently increased our user amount on our RDS 2012 R2. We are starting to experience some issues.

We have 4 Windows 2012 R2 RDS Servers and 1 Domain Controller/File server also running Windows Server 2012 R2.

Every RDS server has +- 10 users, At Max 15.

Every now and then when a users logs on the GPO fails to map the network drives. After logging off and login again it might be working again, the user just has to be 'lucky'. The event log shows the following event:

Event ID: 4098
The user 'Y:' preference item in the 'RDS2012 {AAFF7C11-7514-4CC3-BBC6-C00BBE718106}' Group Policy Object did not apply because it failed with error code '0x80070008 Not enough storage is available to process this command.' This error was suppressed.

We try to connect to the shares using the FQDN.

In a very few cases i had users trying to logon onto the RDS and receiving an error:

The remote procedure call failed and did not execute.

Waiting a few minutes and the user is able to logon just fine.

A third issue is when users are working in an Microsoft Office application they suddenly get a messagebox:

Disk is full or too many files are open

It looks like there is a perfomance issue. But after monitoring it, it seems fine.

RDS Servers:

• CPU usage is around 20-40% most of the time
• RAM usage is at 45-50% (7.7GB/16GB)

Domain Controller/File server: - CPU usage is around 20-50% - RAM usage is at 70-80% 3.2GB/4GB

I have also checked for the amount of open handles in taskmgr and its a total of +- 150k handles. I think this shouldnt be a problem either?

Does anyone have an idea what might be causing these issues?

Edit:

The drive mappings are partially fixed with running them in the user context (configurable in GPO). Now the network drives are added. Sometimes they still are still marked with a red X in 'This PC' but double clicking it fixes the problem in 99% of the cases.

The Disk is full or too many files are open warning message still pops up in Office applications. This is comming from the Auto-save feature.

I ran a Process Monitor and looked at the moment the errors occurred and noticed 2 (strange?) things.

1. While doing a WriteFile on the pipe services on the domain controller/file server the return value is always INSUFFICIENT RESOURCES.

2. The network directory it's trying to read/write the auto-save file from/to has a double backslash in its name. Opening that exact path in windows explorer gives an error. After changing the double backslash to a single backslash i can open the directory just fine.

I checked the GPO redirections and auto-save location in the Office applications and none of these contain a double backslash.