Hi everyone,
Microsoft releases software updates for Windows 10 twice a year through the Semi-Annual Channel. On 2nd October 2018, Microsoft released its latest. I was recently tasked with improving a Citrix XP and PS 4.5 Farm’s performance; by no means was this simple project which I could simply throw more servers at the farm hoping to resolve the issue. By far, the most useful tool in diagnosing slow logons is the userenv.dll debugging available in your Windows out of the box.
Got an issue using Citrix UPM 7.15 LTSR with very slow logons on Windows 10 1703 computers. The environment supports both Windows 10 1703 and Windows Server 2016 RDSH - the WS2016 RDSH logons behave as expected with regular and acceptable logon performance. Windows 10 image has been optimised using the VMWare Optimisation Tool for Windows 10. The Windows 10 images are pooled VDI using PVS using RAM Cache with overflow to disk.
The Windows 10 1703 logons are erratically slow with Citrix UPM enabled - with logon times varying typically from 60 seconds to 3+ minutes. Windows 10 UPM settings have been configured with both absolute base settings (enabling UPM and a path location) alongside detailed UPM configuration with inclusions/exclusions as detailed using Carl Stalhood's blog, with no difference to the end result. When reviewing the UPM logging configured using Citrix Policies it appears that there are 'gaps' of 30 seconds during various stages of the logon process - these gaps are consistent, where it appears no processing is being done. See an example below of the UPM logs (note: I have removed some of the more detailed logging originally performed because otherwise the log would be huuuuge - there was no extra information in there from what I could see that would be a cause for this):
There are two separate 30 second 'gaps' in the above log file which really adds to the logon time. In this example the logon would have been over 2 minutes for the end user. Sometimes in the 3+ minute logons events there are additional more 30 second gaps. The fastest 'no gap' logon is currently at 30 seconds, but this only happens in very rarely.
We have also tested with moving the Windows 10 target devices to an OU with no GPO processing, but the same results happen.
![Receiver Receiver](/uploads/1/2/6/2/126240989/735597888.png)
Also note that for a user's first logon, where the profile is created, performance is adequate and consistent - it's subsequent logons reading from the profile user store where logon performance is not only slow but also erratic - with logons from 60 seconds right up to 3+ minutes.
Once a user has logged on, all appears to be well - the Start Menu roams correctly, and user settings are being saved as required. It's just the logon performance is not up to scratch.
Anyone experienced this? AV exclusions should be in place and not impacting the logon process. Again, RDSH with Windows Server 2016 and UPM appears to be fine.
Thanks in advance!