A network attached server with array of hard drives (NAS RAID) appears to be similar with a regular USB or FireWire external RAID data storage device at first sight, but under the hood they are implemented very differently. The same situation is with a single-HDD NAS versus ordinary USB/FireWire drive.
An external storage with network capability (NAS drive) works almost the same way as a regular computer connected - let’s say for simplicity - to your LAN (local area network at home) with shared resources. Technically, you can consider NAS server as a self-containing computer with its own booting operating system, it has the same network protocols, access rules, login information, and other net-features as the regular computer on the network. Many of modern dedicated NAS devices have integrated support for accessing your files over the Internet.
NAS device can be with a single hard drive inside, or an array of a few hard drives - NAS RAID. Technically, NAS RAID is not just a RAID in the ordinary sense, because it is an array of data partitions on the array of hard drives. Data recovery process from NAS drives has its similarity with data recovery from the standard hard drives; however, it very much differs on the software recovery level. The special techniques are required to be applied, to retrieve the user’s data from damaged NAS drives, since the actual data might be encrypted by default with manufacturer's algorithm integrated in NAS chipset.
RAID-5 is the most common configuration for business used in NAS drives, and this type provides better performance than mirroring as well as fault tolerance. With RAID 5 level, data and parity (which is additional data used for recovery) are striped across three or more disks. Of course, RAID 0 (striping), RAID 1 and its variants (mirroring), RAID 6 (dual parity), and other types and combo-types (like RAID10 = RAID 1+0) or just a simple JBOD (‘Just Bunch Of Disks’) are widely used in different models of NAS devices. NAS storage may contain factory default disk array configuration or user-defined data organization type. Data partitions can also be formatted by user’s choice. Most used formats are FAT32, NTFS, NTFS5 for MS Windows; Linux with Ext2, Ext3, ReiserFX, and XFS format; Unix, BSD, Sun Solaris with UFS, UFS2 (FFS), and little-endian UFS; Novell Netware with NWFS volumes; and Apple Mac OS with HPS, HPS+ and HFSX format.
If you remove the hard drives from NAS device and succeed in rebuilding the array outside of NAS box, more than likely you will see several partitions. First one or two small partitions are for the service purposes and provide all firmware-related software, plus its own operating system. The firmware code on those partitions serves only to boot the NAS Server and supply the interface functions for the network administrator. An extra partition can be also presented on the drive with the swap file for internal NAS OS on it.
Normally the following next largest partition comes with the user’s data. The last small portion of RAID space may be used as extra padding partition between the user volume and the end of the RAID and may contain some NAS service data too. If NAS drive becomes inaccessible due to data corruption only, the software level of NAS recovery doesn't give any problems.
The reality is, when it comes to data recovery, not all hard drives in NAS RAID are fully functional and require a one or more disk repair. Data-R-US is one of the specialized data recovery laboratories with highly qualified data recovery personnel, armed with the latest high-tech instruments for the data rescuing from all types of hard drive and sure enough, from NAS RAID systems. In our laboratory any NAS RAID can be recovered even it comes with few or all failed or malfunctioning hard drives.
Physically damaged drives and drives with internal mechanical or electronic circuit failures go directly to hard drive recovery lab where the each failed drive will undergo full repair and data restoration process. When the number of normally working and repaired drives in RAID matched the required redundancy of array type, we can start safely rebuild and recover data.
Normally, we can recover data from NAS device without knowing all details such as, network configuration, user login, RAID type, or file system, unless the user data has been encrypted. However if you know and can provide us with any technical hints about your network and RAID type and structure details - that would be a big plus to make easy and faster the whole data recovery process for our specialists.
If you connect the suspicious drive from RAID to other computer and still cannot access the raw data:
Under no circumstances you should continue using the device as it may cause further damage to the unit. Also, you should not allow the system to run a repair utility on the drive (such as Scandisk / Chkdsk / Norton etc) - this can often render yet recoverable data to its permanent loss.
Few Live RAID Recoveries
Here, you can read some of the comments from Data-R-US customers: small, large business companies or people living near your home.
The Ohio State University, Columbus: MAC G-RAID External Hard Drive Array
Electrician came into the office to activate new electrical outlets and turned off the power to the office. This caused a premature shutdown of the Mac RAID station. In the few days after this event occurred, the drive would not show up on the desktop immediately upon system power-up, taking a long time to mount and appear. I ran DD rescue on it and it got to a few recovered files before RAID stopping completely. Volume will no longer mount at all and makes two repetitive noises on power-up until it stops making noises completely. Drives in the RAID have not been physically altered, modified, all original parts, enclosure, has not been opened, etc.
Thanks for your help.
Tom from Bronx, NYC: NAS RAID WD My Book World Edition II 2TB (2x1TB) Network Attached Server
Failed RAID-0 with two Western Digital Drives in World Book II NAS case has Linux operating System. Second HDD is in working condition. The first drive is failed together with a blown controller board inside the NAS box. The NAS BOX is WD World Book II (Blue Rings). From the research I have done the drive are in Linux raid linear format. WORD DOC + Photos are critical files, and all other files are less important, but useful too.
Dear Data-R-Us.com team, thank you for excellent data retrieving result.