I understand your point.  If the hardware was sized far in excess of what is needed, you are adding to the cost of supporting your users. You mention that only about half of the 23 mail users registered on the server access their mail on a regular basis, so you have something like 12 active users. Do you ever see or have reported to you slow performance? How many CPUs and how much physical memory is allocated to the two servers?  Do you experience high I/O from Traveler that starts to affect the mail server?

Prominic posted its baseline tests of Domino's performance on 2012 vs. 2016 Hyper-V, and found performance on 2012 to be better. The report was released last August, so it is possible that their results now would be different. It still makes me leary of 2016.

https://prominic.net/2016/08/01/1955/

Thanks Jay,

I haven't really heard about any problems with performance from any of my users. This despite mail databases ranging from 1 - 7 GB with many users storing ALL of their mail in the inbox. There are about 60 GB of mail databases. There are only 4 agents running on the server, and all clients are native Notes clients - no iNotes or Outlook clients.

The Server 2008 R2 VMs are both running with 8 GB RAM and 4 CPUs now with no difficulty from what I can tell.
The current host is a 4 year old HP ML350GS with an Intel Xeon E5645 Six-Core 64-bit 2.40GHz processor with 40 GB RAM and 10K SAS HDD in RAID 10

The replacement I am being quoted is more than double what I paid 4 years ago - they say they are quoting to the same specs.

I have done a lot of Googling and searching this site to try and find even a quick and dirty way to see whether my current system is performing OK - any ideas of things I should be looking at other than complaining users?

We could certainly downgrade to 2012 - I will check out that link.

With virtual servers, a common issue is with sharing the blade with other high I/O servers. In your case, the blade consists of a Domino server and a Traveler server, so any contention for I/O should be easily seen. 

Do your users replicate their mail locally?  If so, they would be fairly well insulated from any blips in server performance. Your users might also benefit by using server-based archiving. Archiving all but the current year of mail should result in faster response when working in their mail file. The older mail would still be available to them. 

I would run Performance Monitor on the server during business hours for a full shift to see if there are any spikes in activity. You can also check platform statistics in Domino (for example, sh stat Platform.LogicalDisk.1.AvgQueueLen.Peak*). The stats that end in PctUtil.Peak like Platform.PagingFile.Total.PctUtil.Peak might be useful in identifying possible bottlenecks. 

I would say that  8 GB RAM and 4 CPUs would be a minimum for a Windows server hosting Domino or Traveler.  

Thanks again for the help Jay - your patience is appreciated!

I do have server based archiving set up to delete and move anything over 2 years old (compromise) and there are only a couple of clients with local replicas.

Are there any counters in particular that might be helpful in Performance Monitor?

I could only find 4 stats that ended in "PctUtil.Peak"

•   Platform.LogicalDisk.1.PctUtil.Peak = 0.7
•   Platform.LogicalDisk.2.PctUtil.Peak = 1,137.53
•   Platform.LogicalDisk.3.PctUtil.Peak = 1.8446480538E+17
•   Platform.PagingFile.Total.PctUtil.Peak = 0.03

The stat for Platform.LogicalDisk.2.PctUtil.Peak concerns me. Is this the Domino data volume?  Your other stats look fine.

I would run Performance Monitor to track Logical Disk access over time. 

Yes - Logical Disk 2 (D) is the virtual hard drive that the Domino program files and data are stored on. The O/S is on C. Here are all the related stats...

[046C:0008-0C40]   Platform.LogicalDisk.2.AssignedName = D
[046C:0008-0C40]   Platform.LogicalDisk.2.AvgQueueLen = 0.04
[046C:0008-0C40]   Platform.LogicalDisk.2.AvgQueueLen.Avg = 1.9684922633E+13
[046C:0008-0C40]   Platform.LogicalDisk.2.AvgQueueLen.Peak = 1.8446741000E+17
[046C:0008-0C40]   Platform.LogicalDisk.2.BytesReadPerSec = 7,303.95
[046C:0008-0C40]   Platform.LogicalDisk.2.BytesWrittenPerSec = 28,772.11
[046C:0008-0C40]   Platform.LogicalDisk.2.PctUtil = 4
[046C:0008-0C40]   Platform.LogicalDisk.2.PctUtil.Avg = 1.9684597882E+13
[046C:0008-0C40]   Platform.LogicalDisk.2.PctUtil.Peak = 1.8446436675E+17
[046C:0008-0C40]   Platform.LogicalDisk.2.ReadsPerSec = 0.45
[046C:0008-0C40]   Platform.LogicalDisk.2.WritesPerSec = 2.73

I will see what perfmon reports.