Broadcom BROADCOM HT1000, Руководство пользователя

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BC4000 Series RAID Controllers User Manual
02/13/06
B ro ad c om C o r p or at i on
Page 44 Understanding Array and Disk States Document BC4000-UM100-R
To copy an array from RAIDConsole, see “Copying Arrays” on page 85 . To copy an array from bcadm, see
“Copying Arrays: bcadm --create-copy” on page 136 .
U
NDERSTANDING
A
RRAY AND
D
ISK
S
TATES
The controller uses states to report the status of arrays and disks. To ensure the health of your data, it is
important to understand what each array and disk state mean as well as what causes them to change. For
information about each RAID type, see
“Overview of Array Types” on page 2 .
Read about:
•
Array States (on this page)
•
Disk States (on page 45 )
•
Rescanning for Changes in State (on page 45 )
A
RRAY
S
TATES
Within the management applications, an array is a logical device that can exist in one of three states:
NORMAL, CRITICAL, or OFFLINE. In RAIDConsole, these states display in the
Array List area in a column
named State . Within the bcadm program, these states also display in a column named State . The states are
defined as follows:
Whether an array is marked as CRITICAL or OFFLINE depends upon what type of an array it is, and how many
disks within the array have failed. Note the following changes in state:
•
For RAID1 and RAID5 (redundant arrays), the CRITICAL state is displayed when a single disk fails.
•
For RAID1n, RAID10, RAID10n, or RAID50 (array types with multiple redundancies), the CRITICAL state
is displayed if a single disk fails in any one of those sets.
•
For Volume and RAID0, the OFFLINE state is displayed when a single disk fails.
•
For RAID1 and RAID5 (redundant arrays), the OFFLINE state is displayed when two or more disks fail.
•
For RAID1n, RAID10, RAID10n (array types with multiple redundancies), the OFFLINE state is displayed
if all disks in a set fail.
•
RAID50 (an array type with multiple redundancies), the OFFLINE state is displayed if two or more disks
fail within the same set.
For example, RAID50 is a stripe of RAID5 sets. If a RAID50 set contains three RAID5 sets, each RAID5 set
can have up to one disk failure and the RAID50 array state shows as CRITICAL. If a fourth disk fails, the state
of the RAID50 array changes to OFFLINE. Or, if two drives fail on one of the RAID5 sets, the state of the
RAID50 array changes to OFFLINE.
NORMAL The NORMAL state is displayed when everything is functioning
correctly.
CRITICAL The CRITICAL state is displayed when the array is no longer
redundant (fault tolerant) because of one or more disk failures. Arrays
can still be read and written to, but the data is no longer protected
should another drive fail.
OFFLINE The OFFLINE state is displayed when arrays cannot be read or written
to because of one or more disk failures.