Use these guidelines when you are installing one or more expansion
enclosures.
About this task
Figure 1 illustrates how the SAS cables
connect to the Storwize® V7000 Gen2 enclosures. Figure 1. Connecting the SAS cables
SAS chain 1 is connected from port 1 of the node canisters in a control enclosure
to the canisters in the expansion enclosures below the control enclosure. SAS chain 2 is connected
from port 2 of the node canisters in a control enclosure to the canisters in the expansion
enclosures above the control enclosure.
Figure 2 shows an example of SAS connections
between a Storwize V7000 Gen3 system and expansion
enclosures. Because the upper canister is inverted from the lower canister, the orientation of the
SAS plugs differ.Figure 2. Connecting the SAS cables to a Storwize V7000 Gen3 system
Be aware of these guidelines when you attach the cables to the SAS ports:
Do not directly connect ports on canisters above the control enclosure with ports on those
canisters below the control enclosure.
Attach cables serially between enclosures; do not skip an enclosure.
Because each control enclosure can support up to 20 expansion enclosures, it might not be
possible to fit all enclosures in a single rack. Instead, install enclosures in adjacent rack space.
Each expansion enclosure is connected into the system by two SAS cables. Different lengths of
SAS cable can be used to connect expansion enclosures to a system in the same rack. Lengths longer
than 0.6 m are typically required to connect between enclosures that are not adjacent in the same
rack.
0.6 m
1.5 m
3.0 m
6.0 m
The last enclosure in a chain must not have cables in port 2 of canister 1 and port 2 of
canister 2.
Ensure that cables are installed in an orderly way to reduce the risk
of cable damage when replaceable units are removed or inserted.
Arrange your cables to provide access to the following components:
USB ports. USB port access is required when you use a USB flash drive to configure the system.
The enclosures themselves. Access is required to the hardware for servicing and for safely
removing and replacing components by two or more people.
Ensure that each SAS cable is fully inserted. A click is heard when the cable is successfully
inserted.
Note: If you make a mistake during cabling and must unplug a SAS cable, pull the blue tag
to release the cable.
Table 1 lists the maximum
expansion enclosures in SAS chains 1 and 2, and the available SAS cable lengths for the
enclosures.
Table 1. Maximum expansion enclosures and cable
lengths
