Backup A Virtual Machine:General Points

With the advent of 2011, there appears to be a significant share of computer users who do not protect their system using backup software. By the same token, many home users are still unprotected from virus damage because they do not run an anti-virus program on their PC on their regular basis. The best protection against virus damage, however, is prevention: purchase good data backup software and run it often!

Simply by looking at the Internet, one may find various pc backup software providers with different strengths in each product. The typical PC user would want their system, application, and files backed up on a regular basis. Usually a simple disk image is enough but more advanced users with more files than the average user may want to invest in good file backup software.

Data loss affects computers but also media. Especially backup media is subject theft because its completeness of information-a company's backup tape in possession of a thief can be a real disaster because the entire company's intellectual property is within that one medium. The thieves can analyze the tape at their leisure, hidden from the public, and leak sensitive material to competitors. The industry's answer to this problem is naturally backup encryption and the recommendation to physically secure backup media, for example in safes.

IT gurus who wish to get their hands on a good server backup software package may want to focus on the file backup capabilities of their product. While a Windows backup may be necessary, it is usually more important to back up files quickly and reliably. The recent growth of Server Core and other installations of limited GUI operating systems may make data recovery plans more complicated since most backup tools do not support such environments. Responsible executives would therefore want to check on their backup tool before planning a data center rollout.

Disk imaging is critical on PCs since users rarely deploy file backup software to protect their data. Usually disk imaging is applied on an entire physical hard drive, but it can also be applied to separate partitions as well, such as a single drive letter. The advantage of drive imaging is that it creates an exact byte-level copy of the information, including hidden file system information, such as residues of deleted files.

Since the advent of virtual machines, virtual machine backup has gained more magnitude. In VMware, a backup a virtual machine while running usually requires the VMDK file to be backed up. To back up VMDK files, however, one needs to either shut down the virtual machine, or the backup program needs to connect to VMware Server to get access to the live virtual disk file. In the latter case a specialized tool may be necessary.

For a successful backup of Hyper-V Server 2008 R2, the backup tool needs to aware and custom-made to fit into the limited operating system landscape created by Microsoft. Because Core Installations are very limited in their OS features, regular tools will not work and specialized Hyper-V backup software needs to be purchased.

In general terms, a virtual server backup software copies virtual server files and settings. To back up virtual machines, one needs to either take them offline from the virtual host server, or a dedicated backup software needs to be applied that works closely with the virtual host server system to access the underlying virtual disks.

A common strategy to save storage space is to generate an incremental backup. Incremental backups always refer to the state of the last backup cycle and extract the difference between the two cycles. The disadvantage of incremental backup is that each incremental step needs to be restored as well during the recovery process; hence, incremental recoveries take longer than that of differential backups.

The latest improvement in the industry is delta compression, also known as file version differencing, which essentially minimizes backup storage requirements to a bare minimum. Delta compression is applied in many areas but is has been predominantly popular on servers with high activity.