Under certain circumstances some or all VMs in a vSphere environment may show the red alert icon and an alert status in a VM list, but no alarm in the VM properties that could be acknowledged or cleared. These “phantom alerts” are an issue for quite some time now and still not fixed.
They seem to be caused by an interruption of the connection to the datastores these VMs reside on, for example by an ESXi host booting while the storage is not up & running. The VMs are first displayed as “disconnected”, but after the datastore connection is restored, the alert status stays.
There is no straightforward way to resolve this, but a vMotion clears the status, most likely because the VM registration is updated. So basically just move the VMs around to clear the alerts, the quickest way is to set the hosts into maintenance mode and evacuate them. A host reboot is not required.
In my previous post I described how to reduce the vCenter memory requirements on Windows. Basically the same is true for the vCenter appliance, but the files are a bit harder to find. Besides that the same disclaimer applies – this is in no way supported by VMware.
Single Sign On:
- Change “JVM_OPTS” (default: “-XX:MaxPermSize=256M -Xms2048m -Xmx2048m”) to “-XX:MaxPermSize=128M -Xms128m -Xmx256m”
- Set wrapper.java.maxmemory (default: “3072”) to “384” (MB)
With vSphere 5.1 the memory requirements of the vCenter server have dramatically increased. If all components reside on a single Windows server [VM], even the smallest inventory size will require 10 GB of memory, according to the VMware Installation and Setup guide. Although this document states a minimum of 4 GB memory for the vCenter Appliance, it is in fact configured for 8 GB RAM after deployment. This will most likely exceed or significantly reduce the resources of small home labs or all-in-one setups with VMware Workstation.
Is this necessary? Nope. But due to the default JVM memory settings a simple reduction of the VMs’ RAM could lead to swapping and have a negative impact on the overall performance, obviously. The following adjustments to the application settings will allow to reduce the VM memory to 4-5 GB. This posting covers a Windows-based vCenter server, the following post will be related to the Appliance.