
Disk Array High Availability Features
61
Produ
ct Des
c
ript
ion
Global Hot Spare Disks
A global hot spare disk is reserved for use as a replacement disk if a data disk fails. Their
role is to provide hardware redundancy for the disks in the array. To achieve the highest
level of availability, it is recommended that one global hot spare disk be created for each
channel. A global hot spare can be used to replace any failed data disk within the array
regardless of what channel it is on.
When a disk fails, the disk array automatically begins rebuilding the failed disk’s data on an
available global hot spare. When all the data has been rebuilt on the global hot spare, the
LUN functions normally, using the global hot spare as a replacement for the failed disk. If a
global hot spare is not available, data is still accessible using the redundant data
maintained by the LUN.
When the failed disk is replaced, all data is copied from the former global hot spare onto
the replacement disk. When the copy is complete, the former global hot spare is returned to
the global hot spare disk group and is again available as protection against another disk
failure.
If a failed disk is replaced while data is being rebuilt on the global hot spare, the rebuild
process continues until complete. When all data is rebuilt on the global hot spare, it is then
copied to the replacement disk.
Global hot spares are an essential component for maintaining data availability. A global hot
spare reduces the risk of a second disk failure and restores the disk array’s performance,
which may be degraded while the LUN is forced to recreate data from parity. The use of
multiple global hot spares may be desirable in environments where data availability is
crucial. Multiple global hot spares ensure that data remains accessible even if multiple
disks fail.
Rebuilding Data
The rebuild process occurs any time a disk failure occurs. It uses the existing data and
parity or mirror disk to rebuild the data that was on the failed disk. Because it is competing
with host I/Os for disk array resources, a rebuild may affect disk array performance. The
effect on performance is controlled by the rebuild priority settings. These settings
determines how the disk array divides resources between the rebuild and host I/Os.
Содержание Surestore Disk Array 12h - And FC60
Страница 16: ...16 ...
Страница 36: ...36 Array Controller Enclosure Components Figure 9 Controller Enclosure Front View ...
Страница 41: ...Array Controller Enclosure Components 41 Product Description Figure 13 Controller Fan Module ...
Страница 44: ...44 Array Controller Enclosure Components Figure 15 Power Supply Fan Module ...
Страница 68: ...68 Capacity Management Features ...
Страница 117: ...Topologies for HP UX 117 Topology and Array Planning Figure 39 High Availability Topology ...
Страница 122: ...122 Topologies for HP UX Figure 40 High Availability Distance and Capacity Topology ...
Страница 126: ...126 Topologies for HP UX Figure 41 Campus Topology ...
Страница 130: ...130 Topologies for HP UX Figure 43 Four Hosts Connected to Cascaded Switches ...
Страница 134: ...134 Topologies for Windows NT and Windows 2000 Figure 45 Four Host Single Hub Single Disk Array Non HA Topology ...
Страница 136: ...136 Topologies for Windows NT and Windows 2000 Figure 47 Four Host Single Switch Dual Disk Array Non HA Topology ...
Страница 138: ...138 Topologies for Windows NT and Windows 2000 Figure 48 Direct Connect Single Host Single Disk Array HA Topology ...
Страница 140: ...140 Topologies for Windows NT and Windows 2000 Figure 50 Four Host Dual Hub Dual Disk Array HA Topology ...
Страница 142: ...142 Topologies for Windows NT and Windows 2000 ...
Страница 158: ...158 Installing the Disk Array FC60 Figure 54 Enclosure EIA Positions for System E Racks ...
Страница 159: ...Installing the Disk Array FC60 159 Installation Figure 55 Enclosure EIA Positions for Legacy Cabinets ...
Страница 161: ...Installing the Disk Enclosures 161 Installation Figure 56 Disk Enclosure Contents ...
Страница 172: ...172 Installing the Controller Figure 62 Controller Enclosure Package Contents ...
Страница 174: ...174 Installing the Controller Figure 63 Mounting the Controller Enclosure ...
Страница 234: ...234 Adding Disk Enclosures to Increase Capacity ...
Страница 274: ...274 Managing the Disk Array Using SAM Unassigned disks selected as hot spares ...
Страница 345: ...HP UX Diagnostic Tools 345 5 HP UX DIAGNOSTIC TOOLS Overview 346 Support Tools Manager 347 ...
Страница 350: ...350 Support Tools Manager Figure 90 mstm Interface Main Window ...
Страница 358: ...358 Support Tools Manager ...
Страница 401: ...Controller Enclosure Modules 401 Removal and Replacement Figure 101 BBU Removal and Replacement ...
Страница 440: ...440 FCC Statements USA Only ...
Страница 466: ...466 Index ...