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Backing up virtual machines: Guide to the latest developments in VM backup

Virtual machine backup can now be achieved with either mainstream backup tools or replication-style methods. Learn more about VM backup best practices in this guide

Backing up virtual machines (VMs) can now be achieved without placing a heavy load on server resources, by using either mainstream backup tools, ones expressly designed for VM backup or via replication-style methods. Download this free Essential Guide to backing up virtual machines for the most recent best practices and to find out more about future trends in virtual machine backup products.

Virtual machine backup appears to have come of age, and we seem to have arrived at a situation in which users can now protect virtual machines and their data in a straightforward way using mainstream backup products. But now we can also protect virtual servers using replication-style methods such as continuous data protection (CDP). In fact, so compelling a solution is the application of CDP to VM environments that we may be witnessing the beginning of the end of backup in its traditional form.

It has been a rocky road to get here. In the beginning it was as if the developers at VMware decided not to think very hard about how virtualised servers would be backed up. You could, of course, just do backup the traditional way, with an agent on every VM. But the I/O loads this brought about would soon show this method to be rather less than optimum, and you had to pay for and manage a lot of licenses.

VMware had its own on-board method of backing up in VMware Consolidated Backup, the consolidated part of which seems a hopelessly misnamed feature in retrospect. Using VCB, backups went through a two-stage process; first, the backup app signalled it wanted to do its work, and then a copy of the full VM or its data or both were snappshotted to a holding disk and the backup taken from there.

Then, late in 2009 VMware brought out the vStorage APIs for Data Protection (VADP), and the two-stage process of VCB was cast into the dustbin of history. With VADP, backup apps talk directly to the VM kernel, and backup products compatible with this include CA ARCserve, EMC Avamar, IBM Tivoli Storage Manager, and NetBackup and Backup Exec from Symantec. Specialist VMware backup products such as Veeam Backup and Quest Software’s vRanger also interface directly with VADP.

The VADP revolution also saw the inclusion of vStorage APIs for multi-pathing to provide better I/O and storage path failover for storage arrays, plus vStorage APIs for Site Recovery Manager to provide array-based replication for block and file-based storage.

At the same time, Microsoft’s Hyper-V also allows backup products to link directly to its hypervisor.

But despite these leaps forward in virtual machine backup, there is another way of protecting virtual machines and their data. Using CDP/snapshots, virtual machine users can now implement a regime of incremental block-level backups forever. By copying data at regular, frequent intervals, there need never be another full backup and the I/O, CPU and memory loads that implies.

So, just as backup as we know it has been made to work in the world of virtual servers, there really is no need for traditional backup after all.

Here’s a look inside the guide:

  • Simplify virtual machine backup with image-level backups, CDP and near-CDP: Backing up virtual machines extensively consumes resources, which can cause issues for storage and backup administrators. Learn about how image-level backups, continuous data protection and near-CDP could help deal with these issues.
  • Virtual server backup evolves from rudimentary process to integrated one: In its infancy, virtual server backup meant using traditional backup tools in the virtual environment, a complex and I/O-heavy process. With the appearance of VMware’s vStorage APIs for Data Protection, it’s a whole new ball game. Learn more about the different ways of backing up virtual machines.
  • Microsoft Hyper-V backup strategies: Hyper-V backup is subject to the same laws of physics as VMware backup: Backing up several virtual machines at the same time creates a server bottleneck. This problem could be solved by backing up virtual machines at the Hyper-V level. In this tip, learn about which Hyper-V backup strategies to use.

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