Alarms can be used to trigger an alert, and that is of course the default behavior of predefined alarms. However you can also create your own alarms and associate an action with it. I am showing the possibilities here and am not saying that this is a best practice, but the following two screenshots show that it is possible to place a host in maintenance mode based on degraded storage redundancy.

First you define the alarm:

And then you define the action:

Again, this is action could have a severe impact when a switch fails and I wouldn’t recommend it, but I wanted to ensure everyone understands the type of combinations that are possible. I would generally recommend to send an SNMP trap or even a notification email… and I would recommend to at least define the following alarms:

• Degraded Storage Path Redundancy
• Duplicate IP Detected
• HA Agent Error
• Host connection lost
• Host error
• Host warning
• Host WWN changed
• Host WWN conflict
• Lost Network Connectivity
• Lost Network Redundancy
• Lost Storage Connectivity
• Lost Storage Path Redundancy

Many of these deal with hardware issues and you might already be monitoring for them, if not make sure you monitor them through vCenter and take appropriate action when needed.

Indeed, “Enter maintenance mode“. Now you might wonder when you would want to use this. Wouldn’t it be nice that when your hardware is degraded, for instance memory status changed or hardware power changed, the host enters maintenance mode. I wouldn’t want to run virtual machines on a host that has a memory error or runs on only one power supply. Of course this action only applies to the “host” objects:

• VMware ESX server Hardware and version
• VMware vCenter version
• Cluster information
• VMware statistics
• Active Snapshots
• CDROMs connected to VMs
• Floppy drives connected to VMs
• Datastores Information such as free space
• RDM information
• VM information such as VMware tools version,  processor and memory limits
• VM’s and there datastore
• VMware timesync enabled
• Percentage disk space used inside the VM
• VC error logs last 5 days

Go to Ivo’s website for the download of the script and the source blog post. I use this script personally just to keep track of changes and get a quick overview of the current situation of an environment.

Virtual Machines may unexpectedly reboot after a VMotion migration to an ESX 3.5 Update 3 Host OR after a Power On operation on an ESX 3.5 Update 3 Host, when VMware HA feature with Virtual Machine Monitoring is active.

There’s a work around for the problem but I will not be posting them here cause they might change somewhere in time. Just read the KB article for more info on how to fix this issue.

Version 4.0 includes comprehensive end-to-end monitoring from ESX Cluster, to ESX Host, to Virtual Machine and to Applications inside the VM. The nworks/Veeam MP now provides integration of application and service data with the VI3 topology. This breakthrough functionality enables a fully integrated picture, with end-to-end monitoring from ESX Servers through to the enterprise applications, such as SQL Server, Active Directory and Microsoft Exchange running inside virtual machines.

Version 4.0 also includes new features such as CIM SMASH hardware sensor status and alerts, graphical representations of data stores, flexible collection intervals, VirtualCenter 2.5 performance counters, and more!

The cool thing about this solution is that is doesn’t rquire agents on ESX or any kind of helper for that matter. Veeam “Management Pack for VMware” relies on the VMware API/SDK, which assures that 4.0 is also fully supported for ESXi. The management pack is an add-on for your current SCOM or HP Ops for that matter.