During Citrix Synergy 2012 in San Francisco it was argued numerous times by Shawn Bass that redirecting Favorites to the home folder is a very bad idea. Shawn mentioned that Internet Explorer causes an extensive number of calls on your file server when browsing so I wanted to dig a little bit deeper into this topic.
Folder redirection to home folder is the rule of thumb to improve logon speed and create a better user experience across platforms. That being said, redirecting AppData should be avoided at all costs.
To redirect or not is a sensible topic and I think it would be a great Geek Speak Session with CTP Shawn Bass and Aaron Parker vs Citrix Consulting Services.
What happens under the hood :
To illustrate this I’ve been using Internet Explorer 9 and Process Monitor on my Windows 7 laptop. The filter beeing used is Path IS C:\Users\Administrator\Favorites.
When opening Internet Explorer you’ll see 13 calls in Process Monitor.
If just clicking the Favorites icon inside IE you’ll get 6 calls, but when scolling the Favorites list you’ll get another 24 calls. This happens only the first time though, so IE is most likely caching this list.
The most interesting findings in this test is the fact that EVERY time the user types an URL into the browser the Favorites folder is queried.
As a comparison Google Chrome handles this much better and only writes when adding new bookmarks. That beeing said, Chrome stores the bookmarks in this file : C:\Users\%UserName%\AppData\Local\Google\Chrome\User Data\Default\Bookmarks so Favorites Redirection won’t affect Chrome.
This test has been conducted on my laptop with only one user browsing the Internet, so imaging the load on your file server when thousands of users are browsing the internet!
Even though redirecting Favorites causes a lot of extra file calls, it’s not nessecary wrong. I mean it depends on the number of users and the file system. If you’re running Windows 2008 R2 file servers make sure to check this blog post : SMB 2.0 Tuning for Citrix XenApp 6.x.
20 thoughts on “Why You Shouldn’t Redirect Favorites to Home Folder”
I once came across an implementation where the cookies folder had also been redirected onto the homedrive. Given the very large number of very small files that comprise your cookies, you can imaging what this did to both the performance of IE and the homedrive fileserver.
Thanks for the comment Neil, this is a very hot topic, good for a discussion for you folks going to Synergy next week. I’ll try following up after Synergy with a webinar.
Nice article Trond. I didn’t know that every time the user types an URL into the browser the Favorites folder is queried.
I don’t disagree with you and Shawn, but it’s always a challenge to get these things right up front in your design so that the user’s settings follow them, including their favorites. And as you’ve pointed out, it’s not necessarily wrong.
Our options to deal with this without a 3rd party profile management solution in place could be to implement a logoff script to sync them into a folder under your network home drive, and a logon script to sync them back from the network. Even then, isn’t this what many 3rd party profile management solution do under the covers? This is essentially what we need to do for Chrome Bookmarks, so why not do it for IE Favorites?
The problem then becomes with how much data we “move” during the logon and logoff process; taking everything into consideration.
I absolutely agree that you should not redirect AppData as pointed out in several other blogs.
In my opinion there are far too many other things to be addressed. Everything has a roll on effect. If your storage suffers due to this issue with redirected Favorites, I’d suggest you have bigger issues with the infrastructure.
Thanks Jeremy, I totally agree with you. All my customers with >1000 users are running with Favorites redirected to the home folder without problems. Citrix Consulting Services even recommends redirecting AppData! so it’s easy for the Admins to get confused.
The case Shawn was involved in was for 10.000 users which brought down the file system for 1/2 day. This is a hot topic and I’ll try following up with some webinars, specially have Pierre and VUEM in mind.
I’m interested in knowing more about Shawn’s customer with 10,000 users. You would expect a customer like this to have enterprise storage such as NetApp, EMC, etc. This sort of storage should be able to cope with these loads unless there was some fundamental issue with the architecture.
AppData redirection is far more complex than doing it or not. I’ve read the blogs from Citrix consultants that explain why they believe there is a valid reason to do it. Their reasons are focused on Desktop Virtualization only. Whilst they may be valid, often confuse people as to how this should be handled across the board outside of a Desktop Virtualisation solution. In this case I agree with Helge and others.
We have actually opted not to redirect the Appdata folder and we use Appsense to help us manage on a Xenapp 6.5 hosted environment. but the 2 things we do redirect are Favorites and the Desktop. I am wondering if we should re-evaluate this approach? Any concerns with redirection on the desktop? Our concern was the tax we would pay on login if we did a copy in and copy out favorites and desktop items on login and log off each time.
There’s always pros and cons with all solutions. Increase login time and reduce network traffic or vica verca. I’ve not tested Desktop redirection, but you do some tests with ProcMon.
Also take a look at Ronny’s comment below.
In my opinion,
It all depends on the performance and network bandwidth/latency/hops to/of the file server / SAN / NAS where is being redirected to. Even folder redirection as-is could become a problem when performance or network metrics are bad.
(I once saw %appdata% redirection from europe to china.. bad idea.. bad design..)
as I was scrolling down the page I thought “well of course you have this problem you testing in IE, try it with Chrome instead”, but then you did.
I take a perspective that you should be able to redirect Favorites to Home Folder, or at least have something that delivers the same user experience. Today that user experience is often best delivered using scripts as Jeremy suggests or a third-party user persona management solution as Paul suggests, but my preferred approach would be to club Microsoft over the head until it wake up to the notion that people want to share a single user experience across multiple devices and deliver something that works properly. Yes I know that this is unrealistic, but what can I say that’s just me.
Simon Says 🙂 Totally agree, Microsoft needs to step up
Hmmm an interesting read, but I don’t agree with him at all !
Who cares if the file share is enumerated, and it takes an extra 15ms, that it would from the network as opposed to locally.
The benefit derived from redirecting to a share, and the support of ‘common look and feel’ without the need for roaming profiles is far greater than the extra 15ms impact to the user. (Oh no wait a slow server, with multiple favorites access by users simultaneously, may instead make it a whole 30ms !!)
Oh the other thing we have implemented successfully is redirect not to the H: drive but an exclusive redirected folder share (so user doesn’t have to see h:\favorites)
I call BS. Show me performance metrics where this is causing problems on a real, reasonably designed system.
Modern servers with gigabit ethernet and SAN storage would hardly notice the traffic generated by having user’s appdata and favorites redirected to their home drives.
And claiming that more users makes the problem worse is bogus as well. You might have 1000 or 10,000 users, but these users are going to be spread out over many Citrix servers, and their home drives are going to be spread out over several file servers, which is going to be backed by SAN storage consisting of dozens or hundreds of spindles.
This sounds like profile management vendor FUD to me.
I’ll show you the problem in our environment with Chrome. The problem I believe is with the sheer number of connections over port 445. We’ve yet to confirm that this is where the performance issues lie but it’s confirmed that the problem is with redirection and with the file server it’s redirected to. It’s hard to measure since there are no performance indicators other than user experience before and after rebooting that server. Monitoring the disk usage shows countless reads and writes from Chrome. The same problem is likely to occur with IE if this is the case.
Thanks for sharing Nathan
Memory management is a major problem in virtual environment it eats up majority of the memory resourse when a IE is launched, having applied all the IE tweeks still IE consuming major memory resourse, Chrome could be a alternate way, but we need to do a lot of testing. do we have standalone installer for chrome ?
I wish some SAN vendors would jump on this thread and comment. Thousands of really small simultaneous disk requests are not trivial on a SAN. Especially when that SAN is busy handling all the other normal file server traffic and VM traffic and whatever else that SAN is doing.
And keep in mind this is just IE favorites. Add in IE cookies and whatever else MS does behind the scenses when Favorites, Cookies, AppDate are redirected.
We are just starting to search down if/what the IETLDcache folder is and how/why it seems to follow either the Favorites or the Cookies. Another index file of some sort (related to the SmartScreen filter maybe).
Then you have a whole different set of questions. If it takes an extra half million or million in SAN equipment to redirect your favorites to handle the extra I/O, is it still worth it?
Great point Hammond
I have real world metrics on this. in a 3 minute capture of an idle VDI session network traffic was ~1.5MB. In a capture of the same VDI session with IE open with 4 tabs in use ~18MB of query traffic is generated. Multiply that times our 50,000 VDI users and you have 900GB of noise throttling the NAS devices and clogging the network. (VDI is using 10Gbps backbone with 1Gbps links) If you have to sync cookies as well you can almost double the traffic. This is an issue and caution should be used when redirecting IE bits.
What is being redirected in this case?
is this just with Favorites or do you have Appdata redirected as well?
Actually, Chrome handles the redirection of Application Data terribly. It writes too much to Appdata Local State and makes calls to the history stored there (reads). It appears IE handles this badly for the same reason.