Slowness in Infor CRM SLX LAN Client Alleviated by Adjusting Windows SMB Settings

Recently, I worked on an issue in which the client was experiencing slowness in Infor CRM SLX LAN client.  Working with Infor, we determined that the issue was caused by the way Windows Server Message Block protocol was interacting with the Infor CRM SLX LAN client, and were able to change the settings to get things working properly.  I had never worked with or given any thought to Windows SMB before this, so I wanted to share what I learned about the Windows SMB settings.

Among other things, Windows uses SMB to cache information about the file and folder searches it conducts.  So, for example, if a file does not exist, Windows would not need to repeat the entire search for that file if looked for again; it would just immediately report that the file did not exist.  However, the SMB protocol can cause slowness when accessing attachment files in the Infor CRM SLX LAN client; a particularly irritating slowness, where absolutely nothing happens for several seconds after trying to save/open/delete an attachment. A quick test to determine if SMB might be the cause is to compare accessing attachments as a normal user vs. a local admin on that computer. If the normal user experiences the delay, but the admin does not, SMB might well be the cause.

It is possible to turn off aspects of SMB caching. Other programs that use the caching might have their performance adversely affected, so I would suggest only disabling the minimum amount needed to improve Infor CRM SLX performance. This caching can be controlled in the Windows registry. Specifically, open regedit.msc, and navigate to the HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Lanmanworkstation\Parameters key. On a standard Windows 10 system, none of the registry values we need to modify will be present, you will need to create them. To set the value to 0, create a new DWORD value in the Parameters key, and set it to as 0. That will turn off the SMB caching corresponding to the key created.

The first piece of caching to disable is the Directory Cache. In the Parameters folder, create the DWORD value DirectoryCacheLifetime and set the value to 0. Test the LAN client to see if the delay in accessing attached files still occurs. If this does fix the issue, I would suggest deleting that key and trying the next one.

If the first key does not work, you should try disabling the File Not Found Cache. In that same registry folder, create the DWORD value FileNotFoundCacheLifetime and set the value to 0. Test as before, and once again delete that key if it does not help.

The final one to try is the File Information Cache. The DWORD value for this cache is FileInfoCacheLifetime. Create and test this one as before. If that does not work, it might be worthwhile to try using all three keys to disable all three caches simultaneously, but most likely you will be faced with looking for other causes at this point. (Remember to get rid of any unnecessary of these three keys, to avoid harming network performance of other applications.)