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Hi Fist Check HDD Size made. you don't need replace all the HDD. If you can buy the same one. you don"t need to reinstall windows again. RAID can be rebuild then you replace mew HDD.
RAID is an acronym for Redundant Array of Inexpensive Disks.
A RAID array is a collection of drives which collectively act as a
single
storage system, which can tolerate the failure of a drive without losing
data, and which can the drives operate independently of each other.
What are the different RAID levels?
A research group at UC-Berkeley coined the term "RAID", defining six
RAID
levels. Each level is a different way to spread data across multiple
drives--a compromise between cost and speed. Understanding these levelsis
important, because each level is optimized for a different use.
RAID Level 0
RAID Level 0 is not redundant, hence does not truly fit the "RAID"
acronym. In Level 0, data is split across drives, resulting in higherdata
throughput. Since no redundant information is stored, performance is
verygood, but the failure of any disk in the array results in all data loss.
This level is commonly referred to as striping.
RAID Level 1
RAID Level 1 is commonly referred to as mirroring with 2 hard drives. It
provides redundancy by duplicating all data from one drive on another
drive. The performance of a Level 1 array is slightly better than asingledrive,
but if either drive fails, no data is lost. This is a good
entry-level redundant system, since only two drives are required.
However,
since one drive is used to store a duplicate of the data, the cost permegabyte is high.
RAID Level 2
RAID Level 2, wwhich uses Hamming error correction codes, is intendedfor
use with drives which do not have built-in error detection. All SCSI
drives support built-in error detection, so this level is of little use
whenusing SCSI drives.
RAID Level 3
RAID Level 3 stripes data at a byte level across several drives, with
parity stored on one drive. It is otherwise similar to level 4.
Byte-level
striping requires hardware support for efficient use.
RAID Level 4
RAID Level 4 stripes data at a block level across several drives, with
parity stored on one drive. The parity information allows recovery from
the failure of any single drive. The performance of a level 4 array is
very good for reads (the same as level 0). Writes, however, require that
parity data be updated each time. This slows small random writes, in
particular, though large writes or sequential writes are fairly fast.
Because only one drive in the array stores redundant data, the cost per
megabyte of a level 4 array can be fairly low.
RAID Level 5
This level is commonly referred to as striping with distributed parity.
RAID Level 5 is similar to level 4, but distributes parity among the
drives. No single disk is devoted to parity. This can speed small writes
in multiprocessing systems. Because parity data must be distributed on
each drive during reads, the performance for reads tends to be
considerably lower than a level 4 array. The cost per megabyte is thesame
as for level 4.
RAID 0/1 or 10
RAID 0/1 is a dual level array that utilizes multiple RAID 1 (mirrored)
sets into a single array. Data is striped across all mirrored sets. As a
comparison to RAID 5 where lower cost and fault tolerance is important,
RAID 0/1 utilizes several drives, in order to provide betterperformance.
Each drive in the array is duplicated (mirrored). This eliminates the
overhead and delay of parity. This level array offers high data transfer
advantages of striped arrays and increased data accessibility (reads).
System performance during a drive rebuild is also better than that of
parity based arrays, since data does not need to be regenerated from
parity information, but copied from the other mirrored drive.
RAID 0/5 or 50
RAID 0/5 is a dual level array that utilizes multiple RAID5 sets into a
single array. In RAID 0/5 array, a single hard drive failure can occur in
each of the RAID5 without any loss of data on the entire array. Keep in
mind, as the number of hard drives increase in an array, so too, doesthe
increased possibility of a single hard drive failure. Although there is an
increased write performance in RAID 0/5, once a hard drive fails and
reconstruction takes place, there is a noticeable decrease in performance,
data/program access will be slower, and transfer speeds on the array will be effected.
RAID Level Uses
Level 0 (striping)
Any application which requires very high speed storage, but does not need
redundancy. Photoshop temporary files are a good example.
Level 1 (mirroring)
Applications which require redundancy with fast random writes;
entry-level
systems where only two drives are available. Small file servers are an example.
Level 0/1 or 10 (mirroring and striping)
Dual level raid, combines multiple mirrored drives (RAID 1) with data
striping (RAID 0) into a single array. Provides highest performance with data protection.
Level 5 (distributed parity)
Similar to level 4, but may provide higher performance if most I/O is
random and in small chunks. Database servers are an example. Level 0/5 or
50 Dual level raid, combines multiple RAID 5 sets with data striping
(RAID 0). Increased reliability and performance over standard RAID5 that
can stand a multiple drive failure; one hard drive per RAID 5 set.
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