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RAID
Data Recovery - How It Works
RAID data recovery
is probably one of the most complex processes any data recovery
firm can perform. More often than not, the problems are compounded
by the actions of the client prior to sending the drives in for
recovery. Many users feel that it is important to try and recover
the data themselves or repair the array through various system utilities,
and this may be fine if the data is not critical. However, it has
been our experience that when you have a RAID failure that has resulted
in substantial data loss, more often than not, somebody's job is
on the line if that data is not recovered. The biggest piece of
advise this article can provide in the event of a RAID failure:
LEAVE IT ALONE!
IT professionals
have a lot of pressure placed on them when a catastrophic system
failure occurs. It is their job to make sure that all systems are
up and running. Many times, out of panic, troubleshooting processes
are initiated in order to correct the problem. Often times these
processes only make a bad situation even worse, and in many instances
they can render the data unrecoverable. Let's keep in mind what
this data can consist of in an average corporate environment. You
are probably dealing with information that cost many hundreds of
thousands, possibly millions of dollars in labor and resources to
create. Much of the data probably can't be duplicated. The intellectual
value alone could be in the many millions of dollars. Corporate
executives really don't care to hear about how the failure occurred,
or what unbelievable string of events led up to the server crashing.
They don't care to hear the technical jargon as you try to explain
to them what happened, and hope they understand that it wasn't your
fault. They only want to know one thing..."why was this data not
backed up, and how can we get it back?"
Instead of taking
chances on your own, call a data recovery professional. RAID data
recovery can be expensive, but in most cases it is much less costly
than trying to recreate the data that has been lost, and getting
the data back may save someone's job. There is a set procedure that
most data recovery professionals follow when it comes to performing
any recovery work. These procedures are followed and expanded upon
when dealing with a RAID recovery. The first step of any RAID recovery
is to make sure all of the drives are functional. In order to properly
complete the recovery it is essential that all drives are fully
functional (this is especially true with a RAID 0). This may involve
taking any physically damaged drives into the clean room, in order
to make the necessary repairs so that they function normally again.
Once that is completed the next step is to make complete sector-by-sector
clones of every drive. This is not "Ghosting", but a very low-level
process that allows the recovery technician to work around bad sectors,
and have complete control over how the drive functions. During the
cloning process, the original source drive that you sent in, is
put in a "write protect" mode so that no data can be written to
that drive. This insures that the original source data is not altered
in any way.
Once the cloning
process is complete, the original drives you sent in are set off
to the side and are no longer touched. The actual recovery process
is performed on the cloned copies, so nothing that is done during
recovery can make the situation worse. After the drives are cloned,
they will be loaded into a system and destriped. Destriping is like
taking the scattered pieces of a puzzle and putting them together
neatly. Simply stated, destriping is taking the data scattered among
the multiple drives that make up array and placing it onto a single
destination drive. From there we have a single drive in which we
can complete what we would consider to be a "normal" recovery. We
can complete this process even at the multi-terrabyte level. If
the damage to the stripe is not too severe, in most cases a complete
rebuild of the directory structure and all associated data can be
completed.
As mentioned
earlier, RAID data recovery can be expensive. Typically a RAID recovery
can be priced around $500 per drive and up. A number of factors
influence the cost, such as RAID type, file system, total size,
situation of failure, etc. ACS Data Recovery is one of the few companies
that do not charge an evaluation fee on complex RAID systems. Even
though the initial price tag of a RAID recovery may be shocking,
many times the costs involved in recovering the data are not even
1% of the data's overall value. So if you are reading this article
and you haven't suffered a RAID failure, what are you waiting for?
Back up your data NOW.
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