Designing A Consoling Solution; Console Switch Types, Tiering, And Port Blocking - HP 16-port SCS Installation Instructions Manual

Designing a consoling solution

Implementation of an efficient multi-server system requires a server management plan. The following
functional aspects of server management should be considered:
x Number of servers – System size determines the number of switches and adapters required.
x Ratio of administrator access paths to servers required – 1 to 4, 1 to 8, or 1 to 16
x Type of access required per server or device to be managed – KVM, serial, local, remote
x Access priority – Tiered switches may restrict KVM access to servers due to port blocking.
x Virtual media requirements – Whether firmware or software of individual servers needs to be
installed or updated remotely
x Remote or integrated Lights-Out functionality
x Use of legacy console switches and adapters – Expanding an existing system may involve
compatibility issues with certain functions.

Console switch types, tiering, and port blocking

HP offers two basic types of virtual media-enabled KVM console switches: the HP IP Console Switch
with Virtual Media and the HP Server Console switch with Virtual Media. Both switch types support
3-level tiering, virtual media support, and a ROM-based OSD interface for local KVM access and
control of any directly connected server.
The HP IP Console Switch with Virtual Media is recommended as a main access or first tier switch for
a management system. It provides both local and remote access. Using IP Console Viewer software
and LDAP integration with Active Directory, HP IP Console Switch remote users can fully manage any
server connected directly or tiered downstream.
The HP Server Console Switch with Virtual Media, on the other hand, enables one or two local KVM
users to fully manage any server connected directly or tiered downstream. When tiered downstream
from an HP IP Console Switch supporting a remote KVM user, the HP Server Console Switch enables
that remote KVM user to access and manage any server connected directly or tiered downstream.
In Figure 6, two groups of servers are managed by a local KVM console connected to the first-tier
switch. Group A servers are connected directly to the main (first-tier) switch, while group B servers are
connected to a second-tier console switch. A third tier can be implemented by connecting one or more
switches to the second-tier HP Server Console Switch with Virtual Media.
While tiering increases switch capacity, it also introduces port blocking. Each port of a console switch
can handle only one active server connection at a time, so mission-critical servers that require priority
access by a KVM console should be connected directly to the first (top) tier switch (such as a Group A
server in Figure 6). All servers connected through the second tier switch (Group B servers in Figure 6)
in effect share a single port of the first tier (main) switch and compete equally for access from the
upper tier switch.
IMPORTANT
While a single KVM console can control up to a theoretical 4,096
servers through three tiers of HP console switches, access requirements
and performance issues make such an infrastructure impractical.
Performance begins to degrade when the IP Console Viewer database
surpasses 1000 objects. Access limitations introduced by port
blocking with third-level tiering becomes problematic.