NAS (Network Attached Storage) is a multi-disk device used as a file server providing data access to a various clients.
Typically, RAID technology is used to combine NAS disks into a single storage, the most common RAID layouts used are RAID0 and RAID5.
Most known NAS vendors are QNAP, Buffalo, NETGEAR, LaCie, Seagate, and Synology.
NASes usually work under Linux operating system and therefore their volumes are formatted to Linux-based filesystems like EXT, XFS, and BTRFS.
NAS data recovery involves disassembling the device, connecting the drives to a PC directly, and using NAS data recovery software like ZAR or
other NAS recovery software (check the detailed comparison of most known NAS data recovery tools).
Note that before you start NAS recovery, you should prepare free disk space equal to the capacity of NAS you are going to recover to copy the recovered data off.