Take your protein pills and get your helmet on Major Tom, we're blasting off with FSLogix.
Overview of FSLogix:
Let’s go beyond that 30,000 foot view and convert the plane to an Elon-esque rocket and look at FSLogix from space. FSLogix is a user profile management tool, with a few extra bonuses but nothing more than this from our view from space. Microsoft’s overview of FSLogix is great (Click Here), but what is FSLogix? cut to the chase already!
FSLogix is not Azure or Azure Virtual Desktop specific or even Nerdio specific. FSLogix is an app that’s been around for several years, acquired by Microsoft in 2018, well before AVD. The goal with FSLogix is to provide a profile solution in a simple and robust profile container for remote environments and even on-prem (I know, sounds wild, right?). It’s a great way to eliminate roaming user profiles or for non-persistent computer environments like an AVD Hostpool with users logging into different hosts on what could be a daily basis. Profiles would no longer be roaming, but rather mounted with FSLogix.
What is FSLogix really doing?
The one sentence answer here would be “When a user logs in, it mounts their profile from a file share.” Yes, that’s what it does. From our orbital view, it looks like this:
- Computer (VM, local desktop, AVD host) is running the FSLogix app/services
- The app is configured to point to a file share storing profiles
- User logs in
- FSLogix goes to that file share and mount’s the user’s profile to the user’s computer. No profile yet? No problem, FSLogix created one when the user logged in
- User logs off
- Profile is dismounted
- Note: this profile is in the form of a VHD or VHDX file, one easy file to manage.
FSLogix does not need to be installed anywhere a user wouldn’t need to mount their profile, and is not needed on the source of the file share. That’s it, we’re all experts now, right?
With FSLogix being Microsoft’s recommend profile solution in AVD environments (link) Nerdio implements FSLogix in our default settings/deployments. We’ve reached the outer edges of the FSLogix galaxy here in support and have seen common errors and questions come up in support. Here’s some things we’ve seen in support requests over the years and solutions/strategies for troubleshooting FSLogix. Prepare for re-entry…
Common Profile Mount Errors:
Now that we’ve safely landed and we’re in our capsule waiting for the rescue team to pick us up, lets talk mount errors. Here’s that error you’ve likely seen at some point:
The grey box of doom! Don’t fear it, this is probably the best FSlogix issue to troubleshoot. There’s an error, and we love an error message.
Event Viewer is your friend!
I personally like to remotely view event viewer from another machine in the environment. I’ll open even event viewer, connect to a remote machine, the computer name of which is already in the error from the “grey box of doom” and check the event logs for FSLogix. The operational logs for FSLogix can be found in:
Applications and Services Logs>Microsoft>FSLogix>Apps>Operational
Look for errors here, they can often give you a very good explanation of what is going on. Here’s those common errors we’ve seen:
File In Use:
Here in support, we’ve seen this as the most common error with FSLogix. When a user logs in, their profile disk (VHD/VHDX) file is mounted from that share location. This file will be locked and in use while the user logged in. If that user attempts to login to another session, they’ll get a profile mount error as the file will be locked.
Now what can you do? If you’re using a file server for storage, you can check for open files (Guide HERE). You’d then want to sign the user out of any sessions they have open/close the open VHD/VHDX file. You may even need to remote into the host and force a user session off if it is a “frozen” session. If using Azure Files for your FSLogix container storage, you can close open file handles directly in Nerdio Manager for MSP's Azure Files module (pretty nifty, eh?).
Permission Issue/Access Denied:
Now, I wish I had some fun trick here, but permissions are permissions and at the end of the day there’s two important permissions here for FSLogix storage. Ensure the user has proper permissions on the file share and proper NTFS permissions.
Share Permissions:
- If using Azure files, users would need the SMB Contributor Role on the Azure Files share (Can be added in NMM Azure Files Module)
- If using a file share on a server, the SHARE permissions should have permissions to Everyone or Authetnicated Users – Full Control
NTFS Permissions:
- I’m going to cheat here a bit and here’s Microsoft’s recommendation on permissions at the NTFS level for FSLogix functionality (a few ways to do this, but here’s what MS recommends):
https://docs.microsoft.com/en-us/fslogix/fslogix-storage-config-ht
Share Cannot Be Reached/Path Not found:
This is an interesting one, if you’ve already verified the permissions on the file share and the NTFS permissions look good, its time exit the capsule and look at the OS level now on the host/desktop. When you see the “Grey Box of Doom”, eject from this box of doom by pressing CTRL-SHIFT-ESC to open Task Manager and the go to File>Run and type in “Explorer.exe”. This should now open a new file explorer window. Try to browse to the path of your share where those FSLogix profile containers are stored. If you can’t reach this, you may have anything from a share permission issue, a DNS issue where the host can’t reach the share by name or even (rarely) an unresponsive file server where the share is stored.
Corrupted Profile:
It happens, profiles get corrupted, we’ve all seen something go wrong at some point and it can happen in FSLogix. Although rare, its fairly easy to diagnose. Event Viewer logs may state the profile is corrupt, but another easy check is on the actual file location for the user’s VHD/VHDX file. Corrupt profiles container files will be renamed with a CORRUPT in the name (how convenient!). If a user has a corrupt profile, you’ll want to try to restore from backups prior to the corruption or if all is lost, you can delete the VHD/VHDXs from the share location and a fresh profile will be created when a user logs in again.
OK, but what about FSLogix problems without a Grey Box of Doom error message?
FSLogix Services not running:
Did users login this morning without an error but they’re missing items from their profile? No worries, the FSLogix services on that machine users are logging into have probably stopped. Restarting the services (You’ll find 2 FSLogix services under services.msc) and having the users logoff/login should do the trick. You’ll want to review those event logs then for FSLogix to possibly determine why the services stopped.
Disk full? How?
Is just a single user running into errors with space? Unable to download files? Generally odd errors in Office products? This could be an FSLogix problem. I know, you’re thinking, “there’s enough free space to build plans for a rocket to Mars”, but FSLogix has a default limit of 30GB on the profile container. When a user reaches this limit, disk full errors, slow response times, and strange errors may start to pop up. Now there’s a very easy solution for this in a recent update to FSLogix, with a simple registry edit, the user’s profile container can be expanded to a larger container size. This LINK (External) has those steps and the older manual means of doing this, but the registry edit is so much easier. I also wrote another community post specifically for this HERE.
NOTE: FSLogix profile containers expand as the profile expands. There are means to compact these, you’ll find some resources out there on the net regarding this, but deleting files will NOT shrink the profile size on disk as the disk has already expanded.
Performance Troubleshooting:
Disk space:
Unrelated to the “disk full” for a single user issue I just discussed, available disk space should be checked routinely to ensure it is not at or near capacity. If your file server or Azure Files share reaches capacity, you can start to see login times increase dramatically, profiles not mount (sometimes with an error) and even profiles unable to save data to the share. Common symptom here is just a black screen at login or a very slow login
Series of Disk and VM
In Azure, premium storage is always recommended for FSLogix container storage. I/O can be taxing upon user login and this premium storage is recommend. Our AVD performance troubleshooting guide in this link HERE has some great info on Disk Performance in the “Disk” portion for those of you using a file server for container storage.
If using Azure files, we would always recommend premium storage for the share and ensure there is adequate space in the quota to accommodate all shares with some room to grow. The quota size of the Azure Files share can increase/decrease performance (IOPS) based on the quota size. Nerdio Manager for MSP can even auto-scale this quota during business hours to give a performance “boost” during these times. You’ll find those options in the Azure Files module in NMM.
If storage performance is not optimal, you can run into what Microsoft calls a “Login Storm” with the storage IOPS being taxed heavily during the morning rush of users logging in and this can manifest itself as a slow login/black screen at user login. For more on performance requirements for FSLogix, please see this link from Microsoft: FSLogix Performance Requirements
FSLogix Bonuses!!!!
App Masking:
Have an app that you only want a subset of users to have access to on a multi-session host? FSLogix has the solution! You can implement app masking to hide apps from users. This tutorial from Microsoft is a great resource on getting started with App Masking via FSLogix: FSLogix App Masking Tutorial
Cloud Cache:
Houston we have a problem, our FSlogix storage share is unavailable. Ground control to Major Problem, you can enable Cloud Cache! Cloud Cache can provide resiliency in the event that connectivity to the profile container’s storage is temporarily lost. You can enable Cloud Cache directly from NMM under Settings>Integrations and then clicking on your FSLogix Profile Storage location. Cloud Cache does have some caveats though, logins may take a bit longer, but for a full overview of Cloud Cache, here’s the link from Microsoft: Cloud Cache for FSLogix Containers
Links:
Nerdio Manager for MSP (NMM) FSLogix KBs and videos:
FSLogix profile container storage options
Troubleshooting FSLogix Profile mount errors in NMM
Unable to Log in to session host VMs as local administrator
Nerdio for Azure (NFA) FSLogix KBs and videos:
Reviewing FSLogix Errors via the Event Viewer
FSLogix-How It Works-What Can Go Wrong?
Troubleshooting FSLogix Profile Mount Errors
There’s a ton of other info on the web regarding FSLogix and deeper dives into settings and optimizations, but hopefully this post launches your FSLogix support engagements to infinity and beyond!!
Thank you,
Chuck M.
Solutions Support Manager at Nerdio
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