Category Archives: ESXi

Expand RDM in virtual compatibility mode

As opposed to the physical RDM mode with the virtual one after expanding the LUN on the storage array side and rescanning HBA vm still can’t see the increased capacity. The official VMware tutorial says to shutdown vm and re-add RDM. This isn’t acceptable.┬áThe hint to make it happen with no downtime is to vMotion vm after rescanning HBA on the destination host. That’s it!

Restarting managements agents

You know the situation when the host stops reporting its performance counters, do you? CPU and RAM load are showing nils.. A simple two-liner to fix the issue at your disposal:

 

Fast Suspend/Resume

Have you ever come across the term in subj? It’s time to reveal what it stands for.
First, three examples when this action can be performed.
To enable CBT for virtual machine in addition to make vm reconfiguration one need to perform so called stun/unstun cycle for vm. This could be power on/off, suspend/resume, create/remove snapshot, vm migration.
Another example is changing the build type for running vm (release/debug/stats). This can be done in vm advanced settings tab or via command line utils. In order to BuildType change is applied FSR is performed transparently by the 5.x hypervisor (for ESXi 4.x vm is actually suspended and then resumed).
And the most frequent one is hot-add hardware to vm.
In fact Fast Suspend/Resume equals to migration to the same host – that’s simple.

Below you can find an example of CBT enabling script (most of backup tools enable it automatically).