Last summer we've changed in our company Avast Pro to Avast Endpoint Protection (about 40 licenses with Small Office Administration console) and Endpoint Protection Suite for servers (5 licenses without SOA). Program version is 8.0.1603.
In the same time we've changed one of our servers, which hosts files (shared folder) for some programs (two separate applications that work on DBF files) accessed over network. First I thought, that problem is the server itself, but further investigation led me to conclusion that it's Avast fault.
What's all about?
Since few months users complain about huge slowdown in some operations in those two applications mentioned before. For example - it takes over 10 seconds to display all customer's invoices. When the aplication is running locally the same operation takes about 1 second and about 1,5 second over network but when Avast is not present in the client system.
I managed to narrow down the problem:
- when client computer is in safe mode with network, the problem don't occur.
- when Avast is disabled (all shields, self-defense, windows service) and should not impact the client system, problem occur.
- it dosen't matter if Avast is installed on server, which host files. It work the same with or without. I tried it with Windows Server 2003, Win 7 Pro, Win XP Pro.
- it doesn't matter if Avast is connected to SOA or works as a standalone
- it dosen't matter if i add network shares to global exclusions
I dug deeper and finally I found out that everything is fine when I delete one of the Avast drivers - aswMonFlt.sys (avast! File System Minifilter for Windows 2003/Vista). Without it programs run smoothly. When it's present in the client system slowdown occurs.
My question is:
How to deal with it? Obviously Avast won't work without aswMonFlt.sys, so I can't delete it. What does this file do? Why global exclusions in Avast don't prevent this slowdowns?
I would be very gratefull for any help or tips. It just can't be this way anymore.
PS. I tried to install newest Avast Pro. Nothing changed. If i remember correctly before installing Endpoint Protection we used Avast 5 and Avast 6. Everything was fine then.
