• CPUs -- you don't need more than four, and probably 2 is sufficient
• RAM -- 32gb may be more than needed, but no harm to keep it there
• DISK -- you definitely want the fastest disks you can afford.
• FOLDERS -- encourage user to not have more than about 8,000 messages per folder.

I'm using Kerio Connect 9.2.5 patch 3 (3336) with 330 users on OS Debian GNU/Linux 8.9, x86_64 in VMWare 6.0 enviroment.

90% of all clients are using Mail.app on MacOS 10.9-.10.11, other clients with OS Window 7 Pro are using Outlook 2010 with Offline Connector on PC Dell OptiPlex 7010 with 240GB SSD and 8GB RAM.

My HW configuration is pretty weak, but everything work like a charm:

CPU: 4vCPU (avg daily usage 5-15%)
RAM: 16GB RAM (avg daily usage 15-30%)
Storage: Local RAID5 (without SSD cache) on Dell PowerEdge R520

what if I create a new vmware machine with the vmware installation from KERIO's website ( i think its linux base) and give it 6vCPUs and 16gb of RAM and 2TB of storage.
My SAN is a HP LeftHand P4330 24tb raw 24 hp disk running at 7.2K rpms

what if I create a new vmware machine with the vmware installation from KERIO's website ( i think its linux base) and give it 6vCPUs and 16gb of RAM and 2TB of storage. My SAN is a HP LeftHand P4330 24tb raw 24 hp disk running at 7.2K rpms

Jorge wrote on Thu, 14 December 2017 18:00

what if I create a new vmware machine with the vmware installation from KERIO's website ( i think its linux base) and give it 6vCPUs and 16gb of RAM and 2TB of storage.
My SAN is a HP LeftHand P4330 24tb raw 24 hp disk running at 7.2K rpms

I would install Linux & use the Linux installer for Kerio Connect, rather than the VMWare appliance that Kerio offers. The appliance (which is debian based, last I knew) is a very 'bare bones' version of Linux, and I found that when I wanted to add any tools or features, it was a struggle. If you and your team have limited skill and experience managing Linux, installing a "full" Linux like Debian gives you some GUI tools, and much better choices around the machine's configuration -- disk sizes, network configuration, etc.

The problem with configuring too many CPUs on the VM boils down to something like this: if the VM doesn't actually need the CPUs, the system and the hypervisor (VMWare) spend more time deciding which CPU to use than actually running the system. I run mine on 2 vCPUs, and the CPU utilization rarely goes about 25%.

As an aside, we installed Samba on our to make access to the mail store a little easier. We used that and ROBOCOPY to move the mail store from the Windows server to the new Linux server. Also, be sure to make a separate virtual disk for the mail store. Install Linux in a small (40GB or so) disk, then add a 2TB one to the VM.

Hope this helps

Jorge wrote on Fri, 15 December 2017 01:00

what if I create a new vmware machine with the vmware installation from KERIO's website ( i think its linux base) and give it 6vCPUs and 16gb of RAM and 2TB of storage. My SAN is a HP LeftHand P4330 24tb raw 24 hp disk running at 7.2K rpms

I would recommend to find out why your current setup is slow or at least, try to measure which part of your infrastructure is the bottleneck. If there is for example some issue with SAN, installing a new VM does not really help.

Can you provide data from Server 2012 Resource Monitor and disk queue from there? If queue is more than 1, then OS cannot write/read disk as fast as it wants.

Can you provide ESXi performance data from storage path? There should be measurements about write latency and read latency.

And can you run test that you shutdown VM, edit ammount of vCPU to 2 and then start VM.