If one component in a redundant pair is offline or powered
off, host access to volumes depends on a Lenovo Storage V7000 Gen2 enclosure or canister in the system.
- If a control enclosure only has one node canister online, access
to a volume depends on the online node canister if the volume is stored
partially or wholly on an array that uses drives in the control enclosure
or its expansion enclosures.
- If one expansion canister in an expansion enclosure is powered
off, any expansion canisters further down that side of the chain become
isolated from the control canister on that side of the chain. In this
case, host access to volumes depends on the online canister if the
volume uses drives in an isolated enclosure or the enclosure with
the offline canister.
- If an entire expansion enclosure is powered off, both the left
and the right side of the SAS chain are broken. In this case, host
access to some volumes can be considered to depend on the entire expansion
enclosure.
The impact that a service procedure might have on host access to
data can be understood by using the management GUI.
- Log on to the management GUI. Go to .
- From the dynamic graphic, right click the canister
and select Show Dependent Volumes to see which
volumes would be inaccessible if the component was taken offline or
powered off.
If during a maintenance procedure, the Show Dependent
Volumes action indicates that there are dependent volumes,
you might choose to stop the procedure to investigate whether it is
possible to reinstate the redundancy in the system so that a procedure
can be carried out without loss of access to data. An example would
be to do procedures to ensure that both canisters in the enclosure
are online before doing another procedure that powers off the only
online canister in the enclosure.