Virtualization requires no justification. It is fait accompli. Today, the deployment of physical servers requires justification. But, virtualization is not easy. It comes with a number of unique issues that have to be addressed in new ways.
First, virtualization reduces the amount of headroom that is available to users, and “backups” are resource intensive. They use up large amounts of server memory, I/O, CPU, and bandwidth. Moreover, the task of backup has to execute quickly so that the business can get on with other mission-critical activities.
Unlike with physical servers, the virtual machine (VM) backup cannot be allowed to consume idle resources for two reasons:
- Most VMs function close to available capacity
- Since a single physical server may be running more than one VM, consumption of the idle resources will impact all VMs running on the server
Second, backup schedules for virtual machines may overlap with schedule runs of backup clients that are running inside the virtual machines. When this is compounded with the headroom problem, the issue becomes more complex. Therefore, the scheduling will have to be done with great care, and with the understanding that the backup load gets multiplied by the number of VMs running on a server, and the number of backup schedules configured for each backup client within the VM.
One solution to these problems may be coordination. The backup jobs could be coordinated at the hypervisor level from outside the host server. This will reduce the load on the resources and take the heat off the scheduling problems. Alternately, the backups can happen on a completely different hardware to prevent any overburdening on the hardware resources.
While virtualization is the best thing that has happened to organizations since computing became widespread, the current backup facilitation for virtual machines leaves much to be desired. Cloud backup service providers need to focus attention on developing their software to accommodate the needs of those who have virtualized extensively. Their customers are looking to them, to provide, the necessary infrastructure and facility to backup their virtual machines.
As a whisper on the aside, experts say that the virtualization industry needs to focus on the following features to deliver excellence in user experience:
- Snapshot technology for virtual machines with synchronization and information for incremental snapshotting
- Application aware backup programs for management of snapshots
- Ability to off-host, access, and manage a VM snapshot
- Ability to control and manage performance penalties that occur during backup
- Making virtual machine backup storage hardware non-proprietary