HP StorageWorks MSA1510i HP Storage Management Utility user guide (383075-002, - Page 87

RAID 0—no fault tolerance, RAID 1+0—drive mirroring, Table 3 RAID 0 features

Get HP StorageWorks MSA1510i PDF manuals and user guides View all HP StorageWorks MSA1510i manuals
Add to My Manuals
Save this manual to your list of manuals

Page 87 highlights

that was originally on the failed drive to the online spare. The system is quickly restored to full RAID-level data protection. (In the unlikely event that another drive in the array fails while data is being rewritten to the spare, the logical drive will still fail.) A spare is assigned to an array and is automatically assigned to all logical drives in the same array. You do not need to assign a separate spare to each array; you can configure one hard drive to be the spare for several arrays. RAID 0-no fault tolerance This configuration (Figure 17) provides no protection against data loss when a drive fails. However, it is useful for rapid storage of large amounts of non-critical data (for printing or image editing, for example), or when cost is the most important consideration. Table 3 RAID 0 features Advantages Disadvantages Highest performance method for writes. All data on the logical drive is lost if a physical drive fails. Lowest cost per unit of stored data. Cannot use a spare. All drive capacity is used to store data (none needed Can only preserve data by backing it up to external for fault tolerance). storage media. RAID 1+0-drive mirroring In this configuration, data on a physical hard drive is duplicated to a second hard drive. NOTE: When only two hard drives are included in the array, this fault-tolerance method is called RAID 1. When more than two hard drives are included in the array, this fault-tolerance method is called RAID 1+0. (RAID_1 is not supported on the MSA1510i storage system.) B1 B1 B2 B2 B3 B3 B4 B4 D1 D2 15314 Figure 19 RAID 1 array, with two physical hard drives (D1, D2) When the array has more than two physical drives, drives are mirrored in pairs (Figure 20). HP Storage Management Utility user guide 87

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
that was originally on the failed drive to the online spare. The system is quickly restored to full RAID-level
data protection. (In the unlikely event that another drive in the array fails while data is being rewritten to
the spare, the logical drive will still fail.)
A spare is assigned to an array and is automatically assigned to all logical drives in the same array.
You do not need to assign a separate spare to each array; you can con
fi
gure one hard drive to be
the spare for several arrays.
RAID 0—no fault tolerance
This con
fi
guration (
Figure 17
) provides no protection against data loss when a drive fails. However, it is
useful for rapid storage of large amounts of non-critical data (for printing or image editing, for example),
or when cost is the most important consideration.
Table 3 RAID 0 features
Advantages
Disadvantages
Highest performance method for writes.
All data on the logical drive is lost if a physical drive
fails.
Lowest cost per unit of stored data.
Cannot use a spare.
All drive capacity is used to store data (none needed
for fault tolerance).
Can only preserve data by backing it up to external
storage media.
RAID 1+0—drive mirroring
In this con
fi
guration, data on a physical hard drive is duplicated to a second hard drive.
NOTE:
When only two hard drives are included in the array, this fault-tolerance method is called RAID 1. When
more than two hard drives are included in the array, this fault-tolerance method is called RAID 1+0.
(RAID_1 is not supported on the MSA1510i storage system.)
D1
D2
B1
B2
B3
B4
B1
B2
B3
B4
15314
Figure 19 RAID 1 array, with two physical hard drives (D1, D2)
When the array has more than two physical drives, drives are mirrored in pairs (
Figure 20
).
HP Storage Management Utility user guide
87