Televaulting supplier Asigra has a new way of backing up virtual servers without the need for agent software on each server. Entire sets of virtual machines (VMs) - individual ones, or files - can be restored.

Asigra's Televaulting v7.0 software now supports VMware virtual servers. Its DS Client product runs in a commodity server at the target site and transfers backup data across a network, using compression and WAN acceleration techniques, to Asigra's DS System backup repository in a datacentre. Only changes are sent, block level changes of the VMDK files rather than the entire virtual machine, after the initial full backup.

Asigra's product offers encryption, de-duplication and continuous data protection with bare metal restore, virtual bare metal for virtual servers of course. Virtual machine restore can be to different hardware if the original physical server is not available. The product's Live VM backup allows administrators to back up VMs in the midst of production operations without disruption to production windows.

According to Asigra, disk-based backup products or services such as Symantec's PureDisk, Signiant's Mobilize for Remote Data Protection, Evault's InfoStage and EMC's Avamar Axion Replicator do not support VMware virtual server backup. Iron Mountain has televaulting services which do support VMware but requires agent software in the target servers and doesn't have a bare metal restore capability.

In a physical server, backup software runs in the machine and backs up individual files and folders or the entire disk data set to a locally connected tape system or disk-to-disk backup box. Televaulting suppliers backup the data over a network to a remote vaulting site by using software agents in each target server or by using a local site appliance, like the Asigra product, which sucks files and folders off the target machines and send them over the network.

Virtual servers can cause backup problems. Typically backup software or agent software running in the server backs up the entire set of virtual machines and taking up CPU resources to do so. Alternatively it runs in individual virtual machines (VM) and backs them up, again using local server CPU resources and also increasing software license costs.

According to IDC, by 2010, 1.7 million physical servers will be shipped to run virtual machines, a threefold increase over 2005. This substantial increase will increase demand for backup products to backup physical servers that may have up to 128 virtual machines running inside them, all with data protection needs.

Pricing uses a capacity-based scheme. The software is now 64-bit and offers orders of magnitude more performance than 32-bit software. A single DS-Client can backup many virtual servers in parallel.

It also means Exchange 2007, which is a 64-bit product, can be backed up and restored.

Tom Dugan, co-founder of the VMware User Group in Philadelphia, said: “Asigra provides the most comprehensive backup offering for VMware."

Lauren Whitehouse, an analyst for the Enterprise Strategy Group, said: “Virtual server environments bring an added layer of complexity when it comes to backup. Asigra’s agentless backup solution is definitely well equipped for this space, bringing a feature set that is positioning Asigra as a standout in VM backup."