For the VMTools Heartbeat monitor:
The heartbeat events as we receive them from the VI-API have been known to be 'unstable'...we can receive the Red event, then within a couple of minutes we receive the "Heartbeat = Green" event. And the guestOS is running fine throughout this time. This is a VI-API issue.....
For this reason this Monitor comes with a configurable timer, set at 10 minutes by default. We will wait 10 minutes to see if a Green event arrives, and only then raise an alert.
It may be in your environment that you need to increase the Timer on this Monitor - this is a standard SCOM override to parameter 'Correlation Interval' (default 600 seconds)
For the totalWriteLatency Monitor -
This is also overridable, so you can configure it for your environment.
However before you override it, I would advise deeper analysis. The MP is reporting high latency between hypervisor and backend storage. Even if you see no clear and direct impact on your VMs now, this Monitor is pro-actively advising you that there is some problem in storage performance.
I would examine the following :
- is the monitor firing Warning or Alert level? (The thresholds are 60 and 100 milliseconds)
- what type of storage is the vmhba attached to? (SAN, NAS, iSCSI etc - you can see which Datastore the vmhba is attached you in nworks Topology view)
- is this latency expected on this type of storage? (100ms = 1/10s for a disk write....that is not great performance and does require checking out)
You can use the nworks Disk performance dashboards to gather more info :
- is there high I/O on the Host vmhba at the same time? (Host Disk Dashboard)
- If yes, which VM(s) cause it? (VM Disk Dashboard)
If you do decide that this latency level is acceptable in your environment, then again you can override one or both thresholds on this Monitor in the standard way.
However I definitely would advise you be pro-active and do a deeper dive into this issue - if you have a performance bottleneck in storage, better to find it now rather than when it goes critical!
Hope that helps - any further questions let us know,