Prior to the upgrade we had a bookmark in our User Portal that pointed to a file share on a Windows 2008R2 server containing approximately 600 items in the root folder which was working fine on 17.5. Now we cannot get anything to show up, the directory is just blank. If we point the bookmark at another share on the same server it works fine. I can go into console mode via SSH with Putty and from the command line I can use the mount.cifs command to mount the share in question to a folder in the /mnt folder. When I attempt to list the files in the mounted share folder I get the same result, it pauses for a while and then stops with no result. Interestingly I can cd to a folder in the share and list the files in that folder without a problem. It appears to be just a problem with a root directory having a certain number of files/directories inside. I tested accessing the same share using a Mint Linux machine and the same mount.cifs command line, that computer did not have a problem listing the folder's contents. It may be something to do with the CIFS modules in the particular version of the Kernel used in 18.0. As a quick and dirty fix I plan on organizing the large directory into several smaller ones to reduce the number of items in the root folder, hopefully that will resolve this for now.
Update: As a test I changed the bookmark so it pointed to a folder in the root directory of the share, much the same as in the console it worked, I was able to see the files inside the folder. I will test the bookmark periodically as I move the files from the root to the subdirectories and see if there is a number of files that breaks it.
Update 2: Turns out the problem was related to a new feature in 18.0, Jumbo frames. I had my LAG interfaces set to 9000 MTU and that was causing the issue with CIFS but only when accessing a folder with a large number of objects. Dropped the MTU back to 1500, SMB share worked again. Bumped it back up to 8050, still working.
