As with all patch management tools, Update Manager is subject to the vagaries of any automated system that attempts to make fundamental changes at the OS layer. Some patches will error, and some will work, but the display and configuration of Update Manager make that dicey reality tolerable to some extent. It's unlikely that we'll ever see a smooth and truly elegant multi-platform patch management solution in our lifetimes, but Update Manager is functional enough to be used on a regular basis, even when dealing with Linux patches -- which should be simpler than Windows, which may be why it doesn't get the attention it deserves.

The other major feature addition is Storage VMotion. Traditional VMotion required that the host servers be connected to the same shared storage, be that iSCSI, NFS, or Fibre Channel, and when a VM transitioned from one physical host server to another, the storage remained in the same location -- only the VM's RAM footprint and network connections were moved. With Storage VMotion, everything can move from one host to another, including the disk. As with traditional VMotion, this happens live, without rebooting the VM.

Storage VMotion can be a slow process, especially if the storage isn't terribly speedy, but it does work. This functionality can be a lifesaver in a number of situations, such as during storage migrations and upgrades. It further reduces the management and maintenance tasks that require a VM reboot, which ultimately helps service uptime and further extends the number of tricks that VMs can do that physical servers can't. Working in concert with Storage VMotion and DRS is the new DPM (Distributed Power Management) capability that can be used to power off dormant hosts if load drops. This nice green feature requires IPM (Intelligent Platform Management) support on the physical servers.

The Halfway Point

VMware did some nice things in this combo dot-five release but could have taken it further. There are still plenty of issues with VI3 that haven't been addressed, not the least of which are the truly obtuse error reporting and logging mechanisms. In one instance, trying to create a RDM (Raw Device Mapping) for a VM to directly interface with an iSCSI LUN would continually fail at the last step with a "General Error" statement that was thoroughly unhelpful. It turns out that the nature of RDM mappings require that pointer files be created on a VMFS file system that reference the iSCSI LUN mapped to the host. If the datastore in use happened to be NFS, then RDM pointers can't be created, and thus can't be used.