Monday, May 9, 2016

DRS Advanced Settings

Recently, I performed a study on DRS, which focused on workload placement of virtual machines to load balance a cluster.

It demonstrated that by using DRS advanced options, we are able to balance memory usage across a cluster. In my next blog post, I examine memory consumption (usage) vs active memory (demand); and discuss the importance of understanding the difference and the impact on workload placement.

Key Terms

Active (Demand) - Amount of memory that is actively used, as estimated by the VMkernel based on recently touched memory pages.
  • Virtual machine:   Amount of guest “physical” memory actively used.
  • Host:  Sum of all active metrics for all powered-on virtual machines plus vSphere services (such as COS, vpxa) on the host.
Granted - The amount of machine memory or “physical” memory that is mapped for a virtual machine or a host.
  • Virtual machine:   Guest “physical” memory that is mapped to machine memory. Includes shared memory amount. Does not include overhead.
  • Host:   Sum of all granted metrics for all powered-on virtual machines, plus machine memory for vSphere services on the host.
Consumed - Amount of memory consumed by a virtual machine, host, or cluster.
  • Virtual machine:   Amount of guest physical memory consumed by the virtual machine for guest memory. Consumed memory does not include overhead memory. It includes shared memory and memory that might be reserved, but not actually used. Use this metric for charge-back purposes.
    vm consumed memory = memory granted - memory saved due to memory sharing
  • Host:   Amount of machine memory used on the host. Consumed memory includes Includes memory used by the Service Console, the VMkernel, vSphere services, plus the total consumed metrics for all running virtual machines.
    host consumed memory = total host memory - free host memory 
Usage - Memory usage as percentage of total configured or available memory.
  • Virtual machine:   Percentage of configured virtual machine “physical” memory.
    active ÷ virtual machine configured size
  • Host:   Percentage of available machine memory.
    consumed ÷ machine-memory-size
Idle – Consumed memory that is not actively used.

DRS Migration Thresholds – The threshold set to automatically migrate virtual machines from one host to another to optimize resource usage.
  • Level 1 – Apply only priority 1 migrations, vCenter will only apply recommendations that must be taken to satisfy cluster constraints like affinity rules and host maintenance.
  • Level 2 – Apply priority 1 and 2 migrations, vCenter will apply recommendations that promise a significant improvement to the cluster’s load balance.
  • Level 3 (default) – Apply priority 1, 2, and 3 migrations, vCenter will apply recommendations that promise at least good improvement to the cluster’s load balance.
  • Level 4 - Apply priority 1, 2, 3, and 4 migrations, vCenter will apply recommendations that promise even a moderate improvement to the cluster’s load balance.
  • Level 5 - vCenter will apply recommendations that promise even a slight improvement to the cluster’s load balance.

Wednesday, March 9, 2016

vRealize Operations 6.2 Overhead Calculation

If you opened up the vRealize Operations Manager Analysis page in the latest version, you will notice it looks considerably different than it has in the past. Previously, you would expect the overhead and demand to show a smaller line than usage. In vRealize Operations Manager 6.2, they have changed the calculations for overhead, which I will walk you through.

The new overhead calculation is Total Capacity - Configured Capacity, the description of total cpacity in vCenter shows Total amount of memory reservation used by and available for powered-on virtual machines and vSphere services on the host. The new overhead model is basically taking the amount of memory that is left over after accounting for all the memory being consumed by virtual machines, vSphere services on the host, and VMkernel core functionality, such as device drivers and other internal uses and subtracting that from the configured capacity.

Wednesday, February 3, 2016

vRealize Operations Manager Maintenance Schedules

I had a customer ask me about Maintenance Schedules today, so I thought I would write up a quick post about them.

Maintenance Schedules stop vRealize Operations Manager from collecting data on a specific object. This can be helpful when resources are offline or in a state of maintenance that could make the metrics misleading. For example, if you are performing monthly patches to Windows Servers, you may not want to capture the restart of the virtual machines every month because you place an abnormal load on system demand that isn't the regular state; which could generate incorrect anomalies and alerts that affect the data for setting dynamic thresholds.

Then again, you may want to ensure the peak state is accounted for in metrics collection for capacity planning purposes. Either way, using Maintentance Schedules can serve a purpose when trying to determine steady state workloads.

To set a Maintenance Schedule, we are going to click Administration and the go to Maintenance Schedules on the Navigation panel.

Tuesday, February 2, 2016

Bada Bing Bada Boom... vROps 6.2 Upgrade

One of the beautiful things about vRealize Operations Manager is how easy it is to upgrade. Version 6.2 of vRealize Operations Manager was released on January 28th, so I decided to upgrade it in my home lab.

To upgrade to the latest version, you need to download the vRealize_Operations_Manager-VA-OS- file from MyVMware. Next we are going to Launch the vRealize Operations Manager admin console, which will be https://vropsserver/admin.

After we log into the admin console, we are going to click Software Updates under the Administration panel.

Tuesday, January 12, 2016

vRealize Operations Manager Super Metrics

Super metrics are the equivalent of a custom metric, it can be used to help simplify tracking by watching a few key metrics instead of many metrics. By bringing forward related data, it helps to troubleshoot specific information, which speeds time to resolution. A super metric is a mathematical formula that contains one or more metrics.

After you create a super metrics, you assign it to one or more object types. For instance, you could assign a super metrics to cluster object (resource kinds) that calculates the average memory demand on all virtual machines in the cluster.

Super metrics can be found on the Content page. vRealize Operations Manager keeps a consistent format, click the + sign to add a new super metrics, the pencil to edit a super metrics, the two triangles to clone a super metrics, the x to delete a super metrics, and clicking the gear icon allows you to import and export super metrics.

News: Top vBlog 2016 Trending: DRS Advanced Settings