RAID DATA RECOVERY
Eco Data Recovery can restore or recover your RAID, SAN,
NAS, Snap Server, and many others. We run multiple, terabyte
capable servers to tackle the larger RAID'S that arrive here
for RAID data recovery.
Utilizing custom software and hardware solutions, Eco
Data Recovery is the ONLY choice for your vital data.
Don't be fooled by companies that offer on-site or worse,
remote recovery options. Before any utilities are run against
a RAID, all the disks must be cloned sector by sector. Anything
less is possibly an irreparable accident waiting to happen.
Just one foul up and ALL your data can be lost. We have recovered
RAID's that have been at many of our competitors labs.
DO NOT SEND YOUR ARRAY TO ANY COMPANY WITHOUT VERIFYING THEIR
CAPABILITIES.
In this day and age, there are more and more companies utilizing
large storage units. There is NO data recovery company that
has the experience of working with, and recovering data from
RAID devices that our company has.
What a RAID (Redundant Array of Independent Disks) is:
RAID 0:
All the disk devices are organized alternatively so that
blocks are taken equally from all disks alternatively, in
order to reach higher efficiency. Since the probability of
finding a block of a file is identical for all disks, there
are force to work simultaneously thus making the performance
of the Meta disk almost 10 times that of a single disk.
RAID 1:
In this mode, the goal is to reach the highest security
of the data. Blocks of data are duplicated in all physical
disks (each block of the virtual disk has a duplicate in each
of the physical disks). This configuration provides 10 times
the reading performance of a single device, but it degrades
writing operations. Read operations can be organized to read
10 blocks simultaneously, one from each device at a time.
Similarly when writing 1 block it has to be duplicated 10
times, one for each physical device. There is no advantage
in this configuration regarding storage capacity.
RAID 4:
In this mode the ultimate goal is to balance the advantages
of the type RAID0 and RAID1. Data is organized mixing both
methods. The physical 1 to N-1 are organized in striping mode
(RAID0) and the Nth stores the parity of the individual bits
corresponding to blocks 1 to N-1. If any of the disks fails,
it is possible to recover by using the parity information
on the Nth hard disk. Efficiency during read operations is
N-1 and during write operations is 1/2 (because writing a
data block now involves writing also to the parity disk).
In order to restore a broken hard disk, one only has to re-read
the information and re-write it (it reads from the parity
disk but it writes to the newly install hard disk).
RAID 5:
This type is similar to RAID 4, except that now the information
of the parity disk is spread over all the hard disks (no parity
disk exists). It allows reducing the work load of the parity
disk, that in RAID 4 it had to be accessed for every write
operation (now the disk where parity information for a track
is stored differs for every track)
RAID 6:
Block-level striping with double distributed parity. Provides
fault tolerance from two drive failures; array continues to
operate with up to two failed drives. This makes larger RAID
groups more practical, especially for high-availability systems.
This becomes increasingly important as large-capacity drives
lengthen the time needed to recover from the failure of a
single drive. Single-parity RAID levels are as vulnerable
to data loss as a RAID 0 array until the failed drive is replaced
and its data rebuilt; the larger the drive, the longer the
rebuild will take. Double parity gives time to rebuild the
array without the data being at risk if a single additional
drive fails before the rebuild is complete.
RAID 0+1:
RAID 0+1: striped sets in a mirrored set (minimum four
disks; even number of disks) provides fault tolerance and
improved performance but increases complexity. The key difference
from RAID 1+0 is that RAID 0+1 creates a second striped set
to mirror a primary striped set. The array continues to operate
with one or more drives failed in the same mirror set, but
if drives fail on both sides of the mirror the data on the
RAID system is lost.
RAID 1+0:
As there is no basic RAID level numbered larger than 9, nested
RAIDs are usually unambiguously described by concatenating
the numbers indicating the RAID levels, sometimes with a "+"
in between. RAID 1+0 - mirrored sets in a striped set (minimum
two disks but more commonly four disks to take advantage of
speed benefits; even number of disks) provides fault tolerance
and improved performance but increases complexity.
RAID is NOT Data Backup!
A RAID system used as a main drive is not a replacement
for backing up data. Data may become damaged or destroyed
without harm to the drive(s) on which they are stored. For
example, some of the data may be overwritten by a system malfunction;
a file may be damaged or deleted by user error or malice and
not noticed for days or weeks. RAID can also be overwhelmed
by catastrophic failure that exceeds its recovery capacity
and, of course, the entire array is at risk of physical damage
by fire, natural disaster, or human forces. RAID is also vulnerable
to controller failure since it is not always possible to migrate
a RAID to a new controller without data loss.
RAID drives can make excellent backup drives, when employed
as backup devices to main storage, and particularly when located
offsite from the main systems. However, the use of RAID as
the main storage solution cannot replace backups.
Data Recovery In The Event of a Failed Array:
With larger disk capacities the odds of a disk failure during
rebuild are not negligible. In that event the difficulty of
extracting data from a failed array must be considered. Only
RAID 1 stores all data on each disk. Although it may depend
on the controller, some RAID 1 disks can be read as a single
conventional disk. This means a dropped RAID 1 disk, although
damaged, can often be reasonably easily recovered using a
software recovery program or CHKDSK. If the damage is more
severe, data can often be recovered by professional drive
specialists. RAID5 and other striped or distributed arrays
present much more formidable obstacles to data recovery in
the event the array goes down.
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