Fix Vmware ESXi vMotion Fails at 14% and error ESX hosts were not able to connect over the vMotion Network

We recently deployed 5-6 new hosts in one of our production Vmware ESXi clusters in order to migrate VMs off older hosts and upgrade them. If you are attempting a vMotion migration between two ESX/ESXi hosts, and the vMotion task reaches 14%, then times out with this error message: The vMotion migrations failed because the… Continue reading Fix Vmware ESXi vMotion Fails at 14% and error ESX hosts were not able to connect over the vMotion Network

VMware vSphere 5.1 vMotion Architecture, Performance and Best Practices

A series of tests were conducted at VMware Performance labs to investigate and compare the performance implications of vSphere 5.1 vMotion over the proven vMotion and Storage vMotion technologies in various scenarios including the migration of a database server and an in-memory application. In addition, live migration tests were performed over metro area network scenarios.… Continue reading VMware vSphere 5.1 vMotion Architecture, Performance and Best Practices

VMware: Unable to migrate VM, missing snapshot file and out of space Error

The error in the headline is right out of snapshot hell. If you have virtual machines (VMs) with large memory requirements, you probably know that you need extra space on the datastore to store the Memory Swap file (.vswp). When datastore housing the VM runs out of diskspace, you will not be able to create… Continue reading VMware: Unable to migrate VM, missing snapshot file and out of space Error

Invalid configuration for device 4 Error When Cloning or vMotion a Virtual Machine

When performing vMotion on a Virtual Machine (VM) or a template on vDS (virtual distributed switch) configuration, you may come across this error: Invalid configuration for Device ‘4’ I experienced this error in my lab over the weekend and removing the VM from the vDS portgroup fixed the issue. According to VMware, the cause of… Continue reading Invalid configuration for device 4 Error When Cloning or vMotion a Virtual Machine

Performance Best Practices for VMware vSphere 5.0

Vmware has relased Performance Best Practices for vSphere 5 and its available by clicking the download link below this short summary. This is a book designed to help system administrators obtain the best performance from vSphere deployments. VMware addressed many of the new features in vSphere 5.0 from a performance perspective. These include: Storage Distributed… Continue reading Performance Best Practices for VMware vSphere 5.0

Mapped direct-access LUN that is not accessible error

On Vmware ESX or ESXi: If you are trying to Vmotion a Virtual Machine (VM) that has a Raw Device Mapping (RDM) attached, you may get an error message saying: virtual disk ‘hd1’ is mapped direct-access LUN that is not accessible. This error usually occurs when there is LUN ID mismatch across hosts. Here is solution from VMware… Continue reading Mapped direct-access LUN that is not accessible error