Choosing better operating system for NAS recovery

Serving the major function of a network device for storing and sharing files NAS storage doesn't require a fully-featured operating system. Normally, the operating system is embedded by NAS vendor. The vendors offer a variety of operating system variants for modern NAS devices in most cases principally based on Linux or BSD operating systems. The article below will help you choose the best host operating system to recover lost data from your NAS storage.

Something about modern NAS

Most popular NAS storages available on the market these days are designed in this way: The network storage consists of one or more drives and is run by an embedded operating system. The drives in multi-drive NASes are normally combined into RAID system to increase operational speed and use storage as efficiently as possible.

With rare exclusions like, for example, hardware RAID of Promise Technology, most NAS vendors offer software solutions. Usually, they are similar in logical design and may differ in style, quality, power consumption, thermal design, noise level and, of course, firmware.

A version of the operating system kernel used for NAS firmware depends on NAS vendor. Among them the most widely applied operating system is some custom Linux designed for embedded microprocessor. Each operating system usually works with its own file system type and its own version of software RAID drivers.

What host OS should I use to recover the data from my NAS?

Note: When you recover data using host Linux OS, it's strongly recommended to backup ALL the critical data before you restart your NAS.

Why not Mac OS?

Modern Apple Mac OS X operating system recognizes RAID structures created by NAS but not all NAS file systems. The main disadvantage of using Mac OS X as host OS for NAS recovery is that if it detects and recognizes RAID structures it can update them to the latest version or 'supported configuration'. For example, RAID10 can be reset to a simple pair of RAID0 with loss of all information about mirroring.

Note: When you recover data using host Apple Mac OS, it's strongly recommended to backup ALL the critical data before you restart your NAS.

And what about Windows?

Any version of Microsoft Windows OS doesn't recognize NAS file systems and its RAID metadata what eliminates the possibility of implicit data damage. Working with NAS from Windows OS you may cause damage to your data only by an incorrect action such as data modification with special tools, initialization or formatting NAS drives and so on.

If you are not sure what steps you should take in the process of data recovery from your NAS, use Windows as host operating system as the most reliable OS that will protect your data from unexpected actions of the operating system.

Note: some drivers on Windows OS offered by third-party vendors for Linux file systems may cause damage or modification to NAS file systems. For this reason it's strongly recommended to disable all the drivers that can conduct read-write operations on Linux file systems before starting data recovery process from your NAS!

Faster NAS or danger to data?

With the aim to increase operational speed of the NAS storage some vendors extend its file system. Such extensions of the file system can be not supported by your desktop Linux. If you mount the file system in read-only mode desktop Linux will report file system errors. And if you run 'fsck' tool or mount file system in read-write mode, this can permanently destroy your data.

And how to recover and not to lose the data completely? First of all, mount NAS file systems in 'ro' (read-only) mode only! Moreover, your data recovery chances will substantially increase with a reliable data recovery software able to support vendor-specific file system extensions. SysDev Laboratories offer UFS Explorer software that will make the entire data recovery process an easy and safe operation.

Deleted files recovery

Ordinarily, due to NAS specifics most data recovery software don't work directly with the storage. To recover lost data from your NAS you should disassemble the storage, connect the drives to a recovery PC and run data recovery software.

Powerful tools of UFS Explorer software will maximize the chances for successful data recovery from your NAS. For multi-drive NAS we offer professional software specially designed to work with complex RAID systems. These software require minimum your effort as they support semi-automatic reconstruction of software RAID.

After completing recovery you may continue using your NAS. For this you should re-assemble NAS drives watching their order and reboot the device. Further on you may store recovered data on your working NAS.

Note: As already mentioned above, any write operations to NAS file system will cause permanent data loss. For this reason you should be careful not to mount the file system in read-write mode, and rather in read-only.

Recovered data, put-back drives... Where are my files???

When you put the drives back into your NAS you should watch the order. Otherwise normal boot process of your NAS will fail and you won't get the files back.

Another danger your files may face is update of RAID metadata caused by desktop Linux OS. Linux OS kernel and the version of software RAID may differ. If Linux updates RAID metadata, the metadata of a new format can be not recognized by NAS anymore. This can result in auto-repair of NAS that will destroy current RAID and create a new empty storage with default settings.

It's strongly recommended to backup ALL the critical data before you restart your NAS.