The flat file format of virtual server disk files should make backup and recovery of entire machines relatively straightforward. But just like any disaster recovery scenario, VMDK recovery is liable to exactly the same problems and flaws as any other file.
Here are some of the factors to consider in the event of a virtual server disk file problem.
Are VMDK files actually being backed up?
Successfully restoring VMDK images relies on having the files backed up in the first place. If something goes wrong in your virtual server environment you will need to know:
- Where the backups are stored.
- The tools and files required for a complete file restore.
VMDK recovery should be relatively simple if both these prerequisites are in place. But what happens if your virtual server is deleted and one or both of these conditions cannot be met?
Disk array failure
Storing backup files on a SAN is relatively common as businesses struggle to manage increasing data volumes. Normally this presents few problems unless the SAN itself experiences a major hardware crash, falls victim to hackers or other malicious intention, or partitions and drives are deleted in error
This can then result in loss of the production VMDK files and the backups. If this is the case, you must proceed with caution to avoid causing further damage. Bring drives online too early could result in arrays being rebuilt before data is recovered, overwriting critical information in the process.
Factors to consider in a successful VMDK recovery
If your VMDK files and backups have been deleted, all may not be lost, but you will need to be incredibly careful to limit further damage. It is essential that disk writes are limited to prevent deleted files from being permanently overwritten; for ultimate protection you should shut down the storage device until recovery work begins.
You may also run into additional complications depending on the backup types you use. Tools designed to make file recovery and management easier can make VMDK recovery much harder if the original image has been lost and backups have been corrupted. Factors like snapshots and thin provisioning make VMDK file rebuilding much more difficult and time consuming.
Prevention is preferable to VMDK recovery
Even though it is possible to recover VMDK files from a formatted drive, it is always preferable to back these files up in such a manner that they are less vulnerable to loss, damage or deletion.
Data recovery is a specialist skill and should not be undertaken lightly – as shown above, the wrong actions could prevent successful VMDK recovery. If in any doubt at all, you should seek professional assistance from an experienced VMDK recovery specialist. Using custom tools and insights from previous projects, these specialists can minimise data loss and restore your virtual servers to a fully operational state far more quickly that most in-house IT teams.
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