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WHAT
IS RAID 0+1? |
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RAID 0+1 requires a
minimum of four drives. Additional drives must be added in
even
numbers.
If
four drives are used, a pair is first striped as in a RAID 0
and then is mirrored
as in RAID 1. The
total storage capacity is calculated by summing the storage
capacity
of all the drives in the array
and dividing it in half. For this reason, RAID 0+1
can be very
expensive. This level does offer increased
performance over some of the other RAID levels
due to the
striping that takes place. Because
there is a mirrored copy of the stripe set, a
RAID 0+1 array allows the
failure of one or
more drives as
long as the failure of each occurs
in the same stripe set.
When this type of drive failure occurs,
the RAID 0+1 essentially
becomes a RAID 0 and is vulnerable to drive
failures in
the mirrored copy.
A RAID 0+1 array is
normally used in
servers that demand high performance. This type of
array is also used in
high capacity external hard drives. For more
information about devices
with
built-in RAID 0+1 technology,
click here.
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The following diagram
illustrates a RAID level 0+1 (a mirror of stripes). |
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WHAT CAUSES RAID FAILURE? |
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There can be many reasons for RAID 0+1 failure.
Listed below are some of the most
common:
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Bad Sectors on the disk |
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Missing
Partitions |
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Corrupt Data in the array |
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Overwritten
Files |
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Corrupt Files in the array |
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Array Backup Failed |
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Corrupt RAID 0+1 Controller |
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Broken RAID |
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Damaged Files on the disk |
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RAID Controller Failure |
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Deleted Files in the array |
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RAID Crash |
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Failed RAID 0+1 |
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Server Crashed |
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RAID 0+1 Drive
Failure |
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RAID
Firmware Failure |
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RAID
Power
Failure |
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RAID Power Surge |
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RAID Rebuild
Failure |
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RAID Will
Not
Boot |
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RAID Disk
Failure |
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MFT
Corruption |
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WHAT
TO DO IF YOU EXPERIENCE A RAID 0+1 FAILURE |
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If you
experience problems with your RAID 0+1 array, please do not attempt
to correct the
problem
yourself. By taking matters into your own hands, you
could overwrite parity data
making RAID
recovery more difficult. Please follow
the steps below and contact ReWave
for assistance at
866-739-2835.
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Turn off your RAID 0+1 device immediately.
This ensures that no additional data
can be written to the array, which could overwrite the data
you are trying to recover.
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Document the events that occurred causing RAID
0+1 failure. Try to
make
notes documenting any problems that occurred and efforts
that were made to fix the
problems. If you remove
the drives from the array, it is
important to label the drives
with the same order in which
they existed in the array. Although not required, this
step will save us time during the RAID recovery process. |
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Contact ReWave immediately. Our data recovery
team is available 24/7 to assist
you with RAID recovery at 866-739-2835. |
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