Should I Use Folder Redirection for AppData


When we talk about XenApp and XenDesktop implementations and the aspects of profiles, we always hear the recommendation to redirect folders. It is a great way to offload portions of your profile to speed up logons, because those folders are not copied down to the system during logon. In fact, I typically recommend the redirection of Favorites, desktop, downloads and My Documents. But the question is what to do about AppData.

I actually had this discussion at BriForum 2010 with a number of people (well, the following discussion is not word-for-word, but you’ll get the idea). You might be thinking, what’s the big deal? Why is AppData so special that we are even discussing it? Let’s look at it from both perspectives:

For redirection

By redirecting AppData, we can expect logons to happen much faster because this folder can become quite large. AppData is all dependent on the applications and some applications store large numbers of files or large sized files in the folder. If we don’t have to copy these file down, then we effectively speed up logons.

Against redirection

Well, some applications use AppData constantly. Certain applications will write and read tons of information to that folder. If the folder is not local, then the application performance might degrade. From this perspective, users are in applications for a larger percentage of time than they are logging in so it would be better to improve a greater portion of time.

For

But by not redirecting the folder, you assume every user will use that application, which is not the case, but I can guarantee that every user using the system has to logon, which means we have a positive impact on everyone. So even though certain users are in the app for a long time, there is a large percentage of users who don’t use the application at all. So in effect, you are hurting their logon times without giving them any benefits.

Against

But application performance is where we end up hearing user complain to the help desk. And honestly, how much of an impact on logon time are we even talking about? An extra 10 seconds? Big deal.

For

You are wrong

Against

Let’s just blame the networking team and be done with it

For

COOL

In the end you have to pick your poison. Do you want a faster logon time or faster application performance? I typically recommend we redirect AppData. IF we see application performance issues, we can use a solution like Citrix Profile Management to allow certain folders to be copied to the local system. This way, we can get the best of both worlds: fast logon and application performance.

Which side do you take?

Daniel – Lead Architect

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4 thoughts on “Should I Use Folder Redirection for AppData”

  1. I’ve always liked Login Consultants Flex Profile solution (now Immidio). It gives great control of which settings to retain and which to discard. Roaming profiles exist for a reason, it is not efficient to access files for continuous read/write access. IMHO SMB was never intended for this scenario.
    Only downside is that the files need to be copied and imported at logon. Citrix Streaming Profile solution seems to be the best of two worlds. I would only like to see an option to precache some parts of the profile, based on what the users tend to start first (Outlook, IE). I hope to be testing Streaming profiles soon so I can give a meaning based on facts rather than on marketing material.

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  2. This is actually quite a complicated issue. Redirecting appdata can cause some applications to perform poorly and actually some legacy applications don’t even like to work with redirection at all (or erratic behaviour happens). If looking at this in a larger perspective of also same profile being used for local logins such as laptops, redirecting roaming appdata will cause Windows Offline Files (CSC) issues with locked file erros etc.

    I like the AppSense solution of virtualizing the profile locations per applications. This gives the advantage of being able to roam just the selected applications, directories or files. The roaming happens by filesystem virtualizatoin, so basically you get the best of all options: quick logons, roaming only the selected applications, appearing as local directory for legacy applications and also good performance because of no SMB access.

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  3. There are also considerations around what OS you’re using, for example in Win7 any redirected folder is automatically marked for offline sync’, so should always be accessed from the local cache rather than from the network location.

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