This article may apply to Neverfail for Fileserver when used with file level anti-virus products.
Virus definition files (DATs) should be kept up to date and in sync on both active and passive servers. Prior to performing a Switchover it is good practice to check DATs are identical on both
servers. This is to ensure:
a) Consistent data on both active and passive servers.
b) Predictable behavior of anti-virus and Neverfail Heartbeat software.
If DATs are newer on the passive than the active server, the following behavior may be observed:
i) Infected files continually ending up on the bad state list
ii) Endless cycles of re-synchronization and 'Apply OOS' events being triggered.
It is also recommended that the configuration of the anti-virus tool is identical on each server. To maintain configurations across servers, any change made on the active server will need to be duplicated on the passive server. Actions performed when a virus is found are particularly important.
Automatic Switchovers (which can be triggered by the Neverfail for File Server Application Module) cannot be prevented from occurring under these conditions. If one does occur, and it is then followed by files failing to be synchronized, administrators should check the versions of DAT files present on both systems, and update where necessary.
See also KB 104 for general information on anti-virus tools.