“Unballooning” RAM that’s been ballooned by VMware

VMware actually has a KB article that has this information: To force the balloon driver to release its hold on memory and prevent the guest operating system from using swap space, use one of these options: Set the value of sched.mem.max to the allocated memory or greater. Select the virtual machine’s Resources > Memory > … Read more

Disk shrink does not work on ESXi guests

http://www.vmware.com/pdf/vmware-tools-cli.pdf Page 13 : Shrinking disks is not allowed under the following circumstances: The virtual machine is hosted on an ESX/ESXi server. ESX/ESXi Server can shrink the size of a virtual disk only when a virtual machine is exported. The space occupied by the virtual disk on the ESX/ESXi server, however, does not change.

VMware ESXi: help downloading large ISO

Around ESXi 6.7, the embedded busybox wget finally started to support https. So finally, you can do https downloads in ESXi. Yay! This is from ESXi 6.7 Update 2. [root@ESXi-X9SRI-3F:/tmp] wget https://www.example.org Connecting to www.example.org (93.184.216.34:443) index.html 100% |******************************************************************************************| 1270 0:00:00 ETA [root@ESXi-X9SRI-3F:/tmp] wget –help BusyBox v1.29.3 (2018-11-02 15:37:50 PDT) multi-call binary. Usage: wget [-c|–continue] … Read more

Why is vCenter 5.1u1 exiting hosts from maintenance mode?

I’ve seen this happen with ESXi 4.1 hosts after a patch accidentally wacked the /tmp/scratch folder. You might want to check if that directory still exists on the hosts that exited maintenance mode automatically. If they’re missing, you’ll want to mkdir to create it. Also, you’ll want to check if persistent scratch is setup correctly … Read more

How to manage a global VM startup order across the whole datacenter?

There doesn’t seem to be a clean way to fully manage a cold start of a virtual infrastructure once HA is configured on the individual hosts. Enabling HA and DRS seems to disable the Virtual Machine Startup and Shutdown options on the host servers. However, any ordering set before the host is moved into the … Read more

VMware Distributed vSwitches (VDS) – Design, theory, *real* use cases and examples?

I do know that a lot of new features are no longer supported on standard switches, such as the network rollback in case of misconfiguration, and network health checking. You can now save and restore your dVS separately, which I think was a big problem for people (which is why some would have recommended avoiding … Read more

Choosing a SAN technology for 100s of VM Web Servers

The key to a good VMWare storage platform is understanding what kind of load VMWare generates. First, since you host a lot of servers, the workload is typically random. There are many IO streams going at the same time, and not many of them can be successfully pre-cached. Second, it’s variable. During normal operations, you … Read more