1 2 Previous Next 15 Replies Latest reply on Feb 10, 2015 5:07 PM by paravirtual

    Outlook .ost files - what to do?

    ctcbod Enthusiast



      We've recently moved to a View 4.6 environment, using linked clones and persistent user data disks (4GB).  Currently all is well as I am using local exchange 2007 for email in non-caches mode.  However, my organisation  is  moving to a hosted exchange solution later this year, and it would make sense to use Outlook in cached mode in this environment for performance reasons. 


      This is a bit of a dilemma as I don't really want ost files on the UDD as I would imagine this will cause heavy I/O on the datastores, plus my initial sizing of the UDD is only 4GB so this would be swallowed up by quite a few of our users' cached mailboxes.  I'm also considering (currently testing) trying to move the ost to a network share somewhere else, but this is an unsupported configuration. 


      So here are my options as I see them


      1.  Use non-cached mode in the hosted exchange environment.  I think this will cause too many unhappy users due to the latency in connecting to our hosted exchange so am trying to avoid this if possible.


      2. Used cached mode and keep the ost on the UDD.  I'll obviously have to monitor datastore I/O very carefully if I do this, and will probably have to give everyone bigger UDDs.


      3. Use re-directed ost files, which as mentioned is unsupported by MS.


      What do you guys think?  Maybe there is a different solution that I've missed (wouldn't be the first time )


      Thanks in advance



        • 1. Re: Outlook .ost files - what to do?



                 Check the following information http://communities.vmware.com/thread/146677


          Hope this information helps you.








          Im a nobody.. nobodys perfect.. therefore IM PERFECT!!! http://imagicon.info/cat/5-59/vbulletin-smile.gif

          • 2. Re: Outlook .ost files - what to do?
            ctcbod Enthusiast

            Thanks for the reply but I'd seen that thread and it does not really help my particular situation.  Thanks anyway.

            • 3. Re: Outlook .ost files - what to do?
              gunnarb Expert

              Well, I can tell you that I don't think you've missed any other solutions.  Using Outlooked in Cached mode is one of the weeknesses of a VDI solution, there just isn't a very straight forward way to do it.  Even the expensive third party utilities don't do a very good job if you are floating your desktops.  If you are doing persistent desktops then using the UDD should work. 


              1) Yep.  Your users will try to strangle you as everything in Outlook will just be slower.  I've done Exchange to Cloud migrations and most cloud providers require cached mode due to this issue.  Users will hate the cloud unless cached mode is enabled.

              2) This is probably your best bet.  My thought here is if you can tier the UDD so it sits on cheap storage (SATA).  Your IO shouldn't be that high for the pst and storage growth would be a concern on expensive storage so why not put it somewhere cheap.

              3) I've tried and wouldn't recommend it.


              What I've been trying to figure out for another customer of mine is if there is any way that Exchange can have a cache proxy on the network somewhere.  I feel like this should be doable but I'm not aware of any solutions that do this.


              Gunnar Berger

              1 person found this helpful
              • 4. Re: Outlook .ost files - what to do?
                ctcbod Enthusiast

                Thanks Gunnar,


                Very helpful - funnily enough, I'm looking at getting in some tiered storage to take some load off my file server, so maybe I can kill 2 birds with 1 stone.  If you don't mind me asking, what's the best way to give the users that currently have 4GB UDDs larger persistent disks?    


                Some kind of exchange cache proxy would be ideal, but It's definately something I'm not familiar with.  Let me know if you find something that will do that!!





                • 5. Re: Outlook .ost files - what to do?
                  ctcbod Enthusiast

                  I've not installed View 5 as yet so need to do some more research, but it looks like Persona Management (on some cheap storage) may also be an option as I could then get rid of my UDDs for good (I hope!)



                  • 6. Re: Outlook .ost files - what to do?
                    gunnarb Expert

                    maybe but it doesn't solve the most issue

                    • 7. Re: Outlook .ost files - what to do?
                      ctcbod Enthusiast

                      no, you're correct, but it's another angle that I can use to attack this from.

                      • 8. Re: Outlook .ost files - what to do?
                        gunnarb Expert

                        Its annoying that something as common as Outlook can't be floated properly (at least not if you need to cache it).

                        • 9. Re: Outlook .ost files - what to do?
                          ctcbod Enthusiast

                          Edit - just seen http://communities.vmware.com/thread/401938?tstart=0 so will look here aswell


                          Hi Gunnar   


                          Just need to renew this post if I may......


                          We've now moved to a hosted exchange\outlook solution and as per my fears, running outlook in non-cached mode is a slow as John Terry! (e.g. snail paced).


                          I want to move to cached mode, but still am yet to decide my best approach this. I would quite like to try one on the following approaches, but as this is new territory for me, I'd like to run it by you - or anyone else wanting to kindly give advice.


                          So basically we have around 90 users, currently with persistent linked clone VMs, each with a 4GB User Data Disks.  This 4GB is OK for some, but we have quite a few users with mailboxes over 4GB, so just switching to cached mode outlook is not an option.  I've managed to find nearly 1TB of space on a different SAN to view so would like to try either:


                          a) Upgrading to View 5.0 and utilise persona management to store roaming user profiles (containing the outlook cached mailbox) on the other SAN - I guess this way I can do away with the UDDs on the linked clones?




                          b) giving everybody a larger UDD on the other SAN.  This seems a little inefficient to me as not all users require larger UDDs.  I'm also unsure on the best way to do this whilst preserving the user profile data.


                          Any advice is welcomed.





                          • 10. Re: Outlook .ost files - what to do?
                            LarryBlanco2 Expert

                            I posted the message on the other thread about Microsoft supporting OST file on the network in a VDI environment.   I don't use view persona management at the moment but use GPO to redirect the location of the ost file using the Outlook GPO adm template.   I have it for about 50 users or so that neede to be in cache mode due to the way they use outlook.  I have not had any problem.  Best thing about it is that I was able to locate the ost file onto sata drives on my netapp and spread the vdi network load across even further.


                            Reason I don't use View Persona Mgmt. is because we use Unidesk to create OS and application layers.



                            my post from the other thread:


                            Microsoft does support the OST files in a network location provided that some things are met:


                            1) High bandwidth / low latency network connection is used

                            2) Single client access to the ost/pst. One outlook client per pst/ost.

                            3) Either Windows Server 2008 R2 Remote Desktop Host or Virtual Desktop Infrastructure (VDI) is used to run Outlook remotely.




                            I would not map an O:\ drive to the desktop. Use GPO to redirect the .OST file to a UNC path \\server\path. That would be the easiest method and not have to worry about mapping drives and giving the user another drive letter.


                            Also, when u do the GPO outlook redirection for ost files. you'll need to delete the users profile and recreated it. Then and only then will it appear in the network location.


                            I have done this and it works really well. This way it doesn't eat up the vm space and can sit on a lower tier storage on the network.


                            Larry B.

                            • 11. Re: Outlook .ost files - what to do?
                              blakebevard Enthusiast



                              If you use folder redirection for the OST file, it will not eat into their data drives as you will be hosting this data and reading it off of a share from another server.  That way you can still control their user data disk size and keep that manageable, but at the same time allocate space for their mailboxes.  Larry is correct and proposed the same solution.  Using the Outlook adm file provides you with the most utility and allows you to best manage your storage while providing your users with an optimum experience.

                              1 person found this helpful
                              • 12. Re: Outlook .ost files - what to do?
                                ctcbod Enthusiast

                                Thanks larry and blakebevard....


                                Good call on the folder redirection option. I'll get this tested and report back.


                                My worry was that using persona management would still involve latency when puling the ost from the share when firing outlook, so folder redirection may be the answer.   And as you say, blake - i can leave the user data disk in place.   

                                • 13. Re: Outlook .ost files - what to do?
                                  ctcbod Enthusiast

                                  Just to say that the suggested method of redirecting the OST via a GPO has worked pretty well.  Very simple to implement and have ended up putting them on our cheaper disk file server.    We have a bit of a performance hit with shared mailboxes though (even though they are stored in the OST) which usually happens when users switch between shared mailboxes, but we can live with this for the time being.  I may try putting some OSTs onto some faster storage to see if it helps and will report back if I see big performance gains.


                                  Cheers all.

                                  • 14. Re: Outlook .ost files - what to do?
                                    LarryBlanco2 Expert

                                    Great to hear that it worked out for you.   Yeah,  to boost performance on the file server your will need spindles.  The more u can fit the better you performance will be. Provided u got a good raid card as well.


                                    Larry B.

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