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CentricStor - Virtual Tape Library Hardware architecture
2.2.1 ISP (Integrated Service Processor)
CentricStor is a group of several processors, each running special software (UNIX
derivative) as the operating system. These processors are referred to collectively as the ISP
(Integrated Service Processor). Depending on the peripheral connection, the hardware
configuration, the software configuration, and the task in the CentricStor system, a
distinction is made between the following processor types:
– VLPs (optional: SVLP = standby VLP)
–ICPs
–IDPs
–ICP_IDP
To permit communication between the processors, they are interconnected by an internal
LAN. The distinguishing characteristics of these processors are described in the following
sections.
2.2.1.1 VLP (Virtual Library Processor)
The processor of the type VLP can be included twice to provide failsafe performance. Only
one of the two plays an active role at any given time: the VLP Master. The other, the Standby
VLP (SVLP), is ready to take over the role of the VLP Master should the VLP Master fail
(see section “Automatic VLP failover” on page 52). The two VLPs are connected to each
other and to the ICPs, IDPs and TVC via FC.
Figure 4: Internal VLP connections
The main task of the VLP Master is the supervision and control of the hardware and
software components, including the data maintenance of the VLM and the PLM. Communi-
cation takes place via the LAN connection
The software which controls CentricStor (in particular, the VLM and PLM) is
installed on all the processors (VLP, ICP, and IDP) but is only activated on one
processor (the VLP Master).
CentricStor
LAN
VLP
FC
FC
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