Ok, but that is not my problem, since i'm allready transferring my files using ftp. The problem is in the synchronise database & filesystem link in the filemanager.
Let me explain some more: (I'm using the ZLDNN photoalbum module for displaying my pictures)
Im adding some pictures to my portal, and place these in the older Portals/0/fotos (using ftp)
After adding some directorys (about 25 with a total of approx 500 pics) i press synchronize database.
After some time i get the following error:
Request timed out. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.Web.HttpException: Request timed out.'

In this case i cannot see my pictures when i choose the option "Add existing photo(s)"

This is what ZLDNN support answered to my question: Thanks for your question. If you use ftp to upload your files, you should synchronize database, wherever there are in root or a sub directory. And you cannot change your portal root. The problem is because there are many files to be synchronized. ...

Considering this problem, is there a solution/workaround for this? E.g. can i manually or synchronise the database differently without getting the request timed out?

Thanx for your answer. Now i did set the request out time to a much higher value in my webconfig (to 900 !!) and also changed the maxRequestLength ot an absurd high value of 1048576, but what happens ...

Again the nasty time out message..

So this can mean three things in my opinion.
- DNN can't handle the large amounts of pictures i try to upload
- My service provider has a very slow IIS running
- I'm still doing something wrong ?! (but what...)

Can you again help me out ?

Restarting the process will not help you.

I have the same problem. The problem is that the syncronization functionality is not optimized for high amounts of files, and when you click synchronize the application takes ALL the files from ALL portals, caches that list (my problem came at around 10 000 files on one host), and for each file extracts that list from the cache, deserializes it and creates a new object (well copy) of the one from cache (also a veeeery expensive operation).

All of this works for a small amount of files, but for a large one (like I had on one host) it lasted for me for about 30-40 minutes each time for the host, and for a portal syncronize (for a portal which had 1200 files) it took about 5-6 minutes.

how many files does your host contain? and how many does that portal contain?