This post was written by Denise Ross
VMware Infrastructure 3 (VI3) solution is aimed squarely at enterprises looking to consolidate full-scale production systems. As such it’s easily the most scalable of the VMware platforms with additional management, load balancing and high availability features, all designed to take full advantage of the underlying virtualisation technology. Installation of the ESX software is simplified in VI3 by a Windows-like, install routine. VMware High Availability (HA) is a worthwhile option, adding automatic failover in the event of a hardware or software problem.
Citrix’s XenServer is a hypervisor that loads and runs directly on a bare server, rather than as an application on a host OS much like the market-leading VMware ESX server. The processors do need to support Intel VT or AMD-V virtualisation technologies, but that’s not been an issue for some time and anything bought recently will support these as standard. with a slicker interface and lots of new features, including the ability to define metadata to group and tag virtual machines.
Vizioncore esxReplicator 2.0 is dependent upon the WAN connection as maintaining replicas can become an extremely slow process. Companies wanting to maintain replicas via slow WAN links should make a backup of the VM and send the backup media to the remote site, where it can be restored; esxReplicator can then continue the replication by sending the only new or changed information to the remote site. Reviewers were also disappointed at the way replicas were updated in the tests. For example, replication jobs failed if the target VM was running.
Parallels’ Virtuozzo Containers 4.0 software doesn’t attempt to emulate the physical machine unlike most hosted virtualization products. Because many of the supporting files and libraries are shared, for example, storage overheads are much lower. This in turn enables Virtuozzo Containers to host a lot more VEs per server than you can virtual machines. Containers can also be deployed quickly with no need to install a new OS every time. Reviewers found creating and managing containers very similar to working with virtual machines except that, because you don’t need to install an OS every time.
Double-Take for VMware Infrastructure suite makes replicas by taking a snapshot of the VM’s disk and sending that along with the original disk to another ESX Server system. After installation, the software runs a wizard to create a new replica. The replication does not appear to run at the maximum speed of the disks or network. Unfortunately switching over to the replica uses a manual process and so requires some experience with VMware ESX Server and VirtualCenter. For example, replicas do not normally appear in the VirtualCenter hierarchy of VMs present on each server.