RAID Data Loss and Data Recovery
by shafa on 2007-09-23
Redundant Array of Inexpensive (or Independent) Disks with the acronym “RAID”, coined by a research group at UC-Berkeley, is a general term for data storage that combine an array of drives collectively to act as a single logical unit. They provide increased data reliability and/or throughput depending on the option or scheme. It is disk subsystem where a set of two or more drives (or discs) with a specialized disk controller contains the RAID operating function. The use of RAID can enhance performance and/ or is endowed with error tolerance.
RAID was developed basically for servers and stand-alone disk storage systems, but can be used on workstations like the desktop PCs. Desktop PC can have RAID added to its system by installing a RAID controller board and additional IDE or SCSI disks. More and more RAID functionality are being built on the motherboard.
Most Small to medium enterprises have gone in for RAID-configured data storage on their servers. RAID even though is very tolerant to faults; does fail sometimes. It may happen due to component failure that includes drive failures, missing partitions, controller failure etc. Data can be lost from RAID due to computer virus and worm damage, bad parity or drives out of order. But the most common cause is user error that often leaves the data unusable and corrupted.
RAID data recovery is very different to hard drive recovery as RAID is a more complex media device. It is more difficult and complicated to retrieve missing data due to drive order, parity, rebuilds, drive synchronization etc. There are six different levels with different way to spread data across multiple hard discs with specific use optimization at each level. It is essential to understand these levels for RAID data recovery.
Most RAID data recovery processes include certain steps like:
• Numbered drives
• forensically sound images of each drive are taken (exact bit by bit copies – including the blank or ‘white’ areas including the redundant drive or drives are taken)
• People in charge of recovering data reconfigure the data into a ‘virtual RAID’ on their multi terabyte server (Like HP Dual Xeon, 4Gb RAM, 8Tb SATA Storage, rack mounted, backed by UPS, backed up with a further 4Tb of storage)
• A list of files are made to be checked by the user to see if all the files he needs are there
• Copies of the data are made to a new drive or drives either external or internal as per the client specification.
The RAID data recovery is achieved through using the latest state-of-art technology, tools and techniques. However, it is ultimately the effort of the recovery experts and the software coders that differentiates between success and failure. An excellent perception and sense of pattern recognition are essential for recovering the missing data from complex RAID configurations
RAID was developed basically for servers and stand-alone disk storage systems, but can be used on workstations like the desktop PCs. Desktop PC can have RAID added to its system by installing a RAID controller board and additional IDE or SCSI disks. More and more RAID functionality are being built on the motherboard.
Most Small to medium enterprises have gone in for RAID-configured data storage on their servers. RAID even though is very tolerant to faults; does fail sometimes. It may happen due to component failure that includes drive failures, missing partitions, controller failure etc. Data can be lost from RAID due to computer virus and worm damage, bad parity or drives out of order. But the most common cause is user error that often leaves the data unusable and corrupted.
RAID data recovery is very different to hard drive recovery as RAID is a more complex media device. It is more difficult and complicated to retrieve missing data due to drive order, parity, rebuilds, drive synchronization etc. There are six different levels with different way to spread data across multiple hard discs with specific use optimization at each level. It is essential to understand these levels for RAID data recovery.
Most RAID data recovery processes include certain steps like:
• Numbered drives
• forensically sound images of each drive are taken (exact bit by bit copies – including the blank or ‘white’ areas including the redundant drive or drives are taken)
• People in charge of recovering data reconfigure the data into a ‘virtual RAID’ on their multi terabyte server (Like HP Dual Xeon, 4Gb RAM, 8Tb SATA Storage, rack mounted, backed by UPS, backed up with a further 4Tb of storage)
• A list of files are made to be checked by the user to see if all the files he needs are there
• Copies of the data are made to a new drive or drives either external or internal as per the client specification.
The RAID data recovery is achieved through using the latest state-of-art technology, tools and techniques. However, it is ultimately the effort of the recovery experts and the software coders that differentiates between success and failure. An excellent perception and sense of pattern recognition are essential for recovering the missing data from complex RAID configurations
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