innovation 发表于 2009-10-1 05:25:29

abuout RAID

RAID and other enterprise server environments have a high degree of fault tolerance however even the most well designed systems are susceptible to malfunctions and RAID systems can hardly be an exception to this rule. There's a litany of reasons that can cause a RAID system failure. Sometimes power fluctuation, software, hardware problems (disk controller malfunctions) or even human error.

Unfortunately when a business RAID, NAS or SANs storage server system first fails, it can be the first sings an unfolding catastrophe. The damage and losses caused by such failures are not only disruptive to productivity, but the down time and outage can also often have astronomical financial consequences if not quickly remedied. At SalvageData we understand this and have rescued many small, medium and large enterprise businesses from data losses resulting from various types of RAID and network storage server media failure outages.

Our in-lab RAID Array Data Recovery services and critical response team of professionals can quickly assess the situation and provide instant access to expert for advice and guidance on how to best address the specific data situation. Once in possession of the server or RAID disk set, we can quickly make the necessary arrangement at our facilities to salvage and recover you data in order to reduce organizational downtime.

Our highly skilled team of RAID recovery professionals can handle the most challenging of RAID recovery scenarios. We can recover data from all types of file servers, application servers, web servers, direct-network attached RAID storage devices, and SAN systems failures.

Commonly used Server RAID Configurations:
SalvageData supports and performs data recovery for all RAID server makes and types, including the most widely used RAID 0, RAID 1 and RAID 5 configurations.

RAID 0

RAID O uses what is called a data striping technique. Multiple hard drives are combined into one large volume. Because it splits the data and accesses both drives in parallel, RAID O reads and writes faster than a non-RAID configuration. RAID 0 doesn't offer data redundancy and requires a minimum of two hard drives to be totally restored as a requirement for completing a successful RAID recovery.

Note: In order to have the best possible chance at performing a successful RAID0 recovery, we often require all drives that were part of the original array at the time of failure.

RAID 1
RAID 1 mirrors, or copies the content of one drive onto another twin drive. If one of your drives should fail, mirroring guarantees optimal data integrity and instant access to your data. Another advantage of RAID 1 is that it allows you to use just 50 percent of your NAS device's available capacity. A requirement for RAID 1 is a minimum of two hard drives and when using more they must be even numbers. The advantage of this type of RAID configuration is that recovery takes less time, resources and tools - assuming that the mirrors functioning correctly when the failure occurred.
RAID 5
RAID 5 offers the best mix of data backup, capacity and performance. Although RAID 5 does stripe all available drives into a single large volume, space equal to one of its hard drives is used to store parity data. If correctly configured, when one hard drive fails, it will use the parity data to rebuild your data. RAID needs a minimum of 3 hard drives. Another backup option RAID 5 offers is hot spare. This reserves an additional hard drive that takes over immediately if another drive fails. Total RAID capacity is calculated by subtracting the space of two drives from the sum of all the hard drives. If you want to use hot spare with RAID 5, you must have a minimum of 4 hard drives.

Note: In order to have the best possible chance at performing a successful RAID5 recovery, we often require all drives that were part of the original array at the time of failure.





All Disk Based RAID Array Configurations:
We not only address the most common RAID configurations mentioned above, but also the more obscure types available to you as well.


Any and all Disk Based RAID Failures:
Regardless of the size, configuration, operating system or platform of your enterprise storage system, whether it be a multi-disk RAID array system, SAN, NAS or other multi-disk server system, SalvageData‘s highly qualified engineers can salvage your data even if all other means of recovery have failed.

Common RAID Failures Include:
RAID controller failure
Rebuild failure
Damaged striping
Multiple drive failure (or multiple drives go offline)
RAID array or volumes that won't mount after a server crash
Configuration damage or corruption
Addition of incompatible drives
Hardware conflicts
Software corruption
Viruses or malicious intent
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