. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ESM Canisters
7
ESM Canisters
An environmental services monitor (ESM) provides the interface between the disk drives
in a drive module and the hosts. The hosts connect directly to the ESMs. Each drive
module contains two ESM canisters.
shows an ESM canister that is being inserted into the rear of a drive module.
Figure 5
Service for the ESM Canister is from the Rear of the Drive Module
Redundancy
When a drive module contains two ESMs, if one ESM fails, the other ESM will provide a
data path to the disk drives. You can replace a failed redundant ESM while the power to
the drive module is turned on and the drive module is processing data.
Connections
The ESM attaches to the host using SAS cables. The ESM has two SAS connectors.
•
SAS-in
– Used for cables from the host to the ESM.
•
SAS-out
– Not used.
shows the SAS pinout connections on the SGI host system’s standard I/O port.
Figure 6 SAS Pinouts on SGI Host System I/O Port
shows the SAS connectors on an ESM.
Pin 1
Pin 8
Summary of Contents for InfiniteStorage 120
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