VMFS Recovery Usage Methodology
Nowadays data is stored in a multi-layer environment because of a wide variety of devices, operating systems, and complex infrastructure. It is common for large storage media to use different hardware and software RAID levels, virtual machines, SAN, or NFS systems. All these technologies and file systems form some kind of layers that need to be read and set in a proper order to gain access to required data.
Nobody would doubt that the best way to read data is using an original and undamaged file system. This is true also for data recovery, it's recommended to stick to as close to original storage structures as it's possible. Therefore if data is stored within several file systems and RAID levels we need to get the most out of each layer and apply all possibilities to read it in its original state.
The second important thing: is locating damage that prevents normal work of the storage system. This could be a broken RAID disk, disk with the deleted partition table, or deleted file.
Thus data recovery is basically an attempt to read data stored in the original file system with all the original layers. Additional treatment is applied to the damaged layers if necessary. This “treatment" will consist of RAID reconstruction, searching for deleted partitions, or reconstructing the file system. Selecting a proper method depends on suspected or detected damage.
We do our best to provide automated data recovery solutions, yet some tricks and hints could help you achieve better results. I've grouped them by data storage layers.
Overall recovery process can be split into the following steps:
- Access to the datastore
- Recovering data
- Mount recovered VMDK
- Interpreting results
- Consider purchase if you like the results
- Saving recovered data
Let's take a closer look at each step.