==== Required information ====
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====Hi,

After latest update, we bought support tickets to fix config  and quarantine issues, (which also figures some minor errors with configs) , all was working good for some time , and then we got hit with a heavy load of antivirus (+some load of apache).  We hit ~laod of 10.0 with 2 cores, which made us very slow.

My questions are :
1. Why this could have happened? (which parats of system should i review to find the cause)?
2. Can we lower the number of threads for antivirus ?
3. Can we make antivirus work faster , maybe do not use heuristics or smth ?
4. Any other suggestions are welcome

PS - as a temporary solution, i have increased number of CPU cores to 8 , so now even if we hit the same situation probably it will overcome it faster, but i would like to somehow understand why this could have happened ?

PPS- never before we had such big load on a server for years of work.

==== Required information ====
iRedMail     v0.9.7
iRedAdmin-Pro     v2.8.0 (MySQL)
Ubuntu 14
- Web server -Apache:
====