Zimbra *very* slow after update to 5.0.18

[NaughtyusMaximus]

I updated from 5.0.16 to 5.0.18 this past weekend, and since then, my CPU utilization has jumped from hovering around 0-25% of 4 cores up to nearly 100% steady on all four cores. It gets so bad and slow that when I come in to work in the morning, I basically need to restart the zimbra service before things speed up to a normal level. The restarting of the service drops the RAM usage down from ~3GB to 1.5GB for a few hours, and the system load drops from ~20 down to under 10. Before the upgrade, the load was usually under 1.

Is there anything I can look for to fix this? Or at least to try to figure out where the problem is coming from?

Looking at htop, occasionally I'll spot 'amavisd (virgin child)' come up near the top, but if I ps -ef | grep amavis , it isn't shown there. Is this a red herring?

[rafaelsantos]

What steps you did to upgrade from 16 to 18?

[NaughtyusMaximus]

sudo ./install.sh , and then followed the directions there

[uxbod]

Shutdown ZCS, and then check no zombie zimbra processes are running

ps aux | grep zimbra

If so kill them all off nicely and then restart ZCS. See how you get on.

[NaughtyusMaximus]

Yeah, that works most of the time, but I have to do that more than once a day, which isn't exactly good when I have half of my users in the opposite timezone as me