HP NetRAID 1Si Controller - Manual (Page 151)

Glossary
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and the hot-spare disk must have sufficient capacity. The system administrator can
replace the failed disk module and designate the replacement disk module as a
new hot spare.
Hot-Swap Disk Module: Hot-swap modules allow a system administrator to
replace a failed disk drive in a server without powering down the server and
suspending network services. The hot-swap module simply pulls out from its slot
in the drive cage because all power and cable connections are integrated into the
server backplane. Then the replacement hot-swap module can slide into the slot.
Hot swapping only works for RAID 1, 3, 5, 10, 30, and 50 configurations.
I
2
O: Intelligent Input/Output (I
2
O) is an industry-standard, I/O subsystem
architecture independent of the network operating system and the peripheral
devices supported. I
2
O uses drivers that are split into operating system services
modules (OSMs) and hardware device modules (HDMs).
Initialization: The process of writing zeros to the data fields of a logical drive and
generating corresponding parity to put the logical drive in a Ready state.
Initializing erases previous data, generating parity so that the logical drive will
pass a Consistency Check. Arrays work without initializing, but they may fail a
Consistency Check because parity fields may not have been generated.
I/O Driver: A host HP NetServer software component (usually part of the
operating system) that controls the operation of peripheral adapters or adapters
attached to the host HP NetServer. I/O drivers communicate between applications
and I/O devices, and in some cases participate in data transfer.
Logical Drive: A virtual drive within an array, which may occupy more than one
physical drive.
Logical drives divide up the contiguous storage space of an array of disk modules
or a spanned group of arrays of disks. The storage space in a logical drive is
spread across all the disks in the array or spanned arrays. Each HP NetRAID
Series adapter or integrated HP NetRAID controller can be configured with up to
eight logical drives in any combination of sizes. Configure at least one logical
drive for each array.
A logical drive can be in one of three states (also see the SCSI Disk Status below):
•
Online: All participating disk modules are online.
•
Degraded: (Critical) a single disk module in a redundant array (not RAID
0) is not online. Data loss may result if a second disk module fails.
•
Offline: Two or more disk modules in a redundant array (not RAID 0) or
one or more disk modules in a RAID 0 array are not online.