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22 prioritized port and wwn control (ppc), 23 hitachi parallel access volume (hpav), 24 dynamic link manager™ (dlm) – Compaq 9900 User Manual

Page 64: 25 ldev guard, 26 hitachi cruisecontrol

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50 Chapter

3

Functional and Operational Characteristics

3.7.22 Prioritized Port and WWN Control (PPC)

Prioritized Port Control (PPC) allows open-system users to designate prioritized ports (e.g.,
for production servers) and non-prioritized ports (e.g., for development servers) and set
thresholds and upper limits for the I/O activity of these ports. PPC enables users to tune the
performance of the development server without affecting the production server’s
performance.

Note: For further information on PPC, please see the Hitachi Lightning 9900™ Prioritized
Port and WWN Control User’s Guide
(MK-90RD030), or contact your Hitachi Data Systems
account team.

3.7.23 Hitachi Parallel Access Volume (HPAV)

Hitachi Parallel Access Volume (HPAV) enables the S/390

®

host system to issue multiple I/O

requests in parallel to single logical devices (LDEVs) in the Lightning 9900™ subsystem. HPAV
can provide substantially faster host access to the S/390

®

data stored in the 9900 subsystem.

The Workload Manager (WLM) host software function enables the S/390

®

host to utilize the

HPAV functionality of the Lightning 9900™ subsystem. The 9900 supports both static and
dynamic HPAV functionality.

Note: For further information on HPAV, please see the Hitachi Lightning 9900™ Hitachi
Parallel Access Volume (HPAV) User and Reference Guide
(MK-91RD047), or contact your
Hitachi Data Systems account team.

3.7.24 Dynamic Link Manager™ (DLM)

Hitachi Dynamic Link Manager™ (DLM) provides automatic load balancing, path failover, and
recovery capabilities in the event of a path failure. Dynamic Link Manager™ helps guarantee
that no single path becomes overloaded while others are underutilized.

Note: For further information on DLM, please see the Hitachi Lightning 9900™ Hitachi
Dynamic Link Manager™ User’s Guide
for your host platform (see Table 4.7), or contact your
Hitachi Data Systems account team.

3.7.25 LDEV Guard

LDEV Guard enables you to assign access permissions (Read/Write, Read-Only, and Protect)
to logical volumes in your disk subsystem using a Remote Console PC or a host command.

Note: For further information on LDEV Guard, please see the Hitachi Lightning 9900™ LDEV
User’s Guide
, or contact your Hitachi Data Systems account team.