Problem: New Expansion Enclosure Not Detected; Problem: Mirrored Volume Copies No Longer Identical - IBM Storwize V7000 Unified Problem Determination Manual

v No more than five expansion enclosures can be chained to port 1 (below the
control enclosure). The connecting sequence from port 1 of the node canister is
called chain 1.
v No more than four expansion enclosures can be chained to port 2 (above the
control enclosure). The connecting sequence from port 2 of the node canister is
called chain 2.
v Do not connect a SAS cable between a port on an upper canister and a port on a
lower canister.
v In any enclosure, the same ports must be used on both canisters.
v No SAS cable can be connected between ports in the same enclosure.
v For any enclosure, the cables that are connected to SAS port 1 on each canister
must attach to the same enclosure. Similarly, for any enclosure, the cables that
are connected to SAS port 2 on each canister must attach to the same enclosure.
Cable attachments for SAS port 1 and cable attachments for SAS port 2 do not
go to the same enclosure.
v For cables connected between expansion enclosures, one end is connected to port
1 while the other end is connected to port 2.
v For cables that are connected between a control enclosure and expansion
enclosures, port 1 must be used on the expansion enclosures.
v The last enclosure in a chain must not have cables in port 2 of canister 1 and
port 2 of canister 2.
v Ensure that each SAS cable is fully inserted.

Problem: New expansion enclosure not detected

This topic helps you resolve why a newly installed expansion enclosure was not
detected by the system.
When installing a new expansion enclosure, follow the management GUI Add
Enclosure wizard, which is available from the Manage Devices Actions menu.
If the expansion enclosure is not detected, perform the following verifications:
v Verify the status of the LEDs at the back of the expansion enclosure. At least one
power supply unit must be on with no faults shown. At least one canister must
be active, with no fault LED on, and all the serial-attached SCSI (SAS) port 1
LEDs must be on. For details about the LED status, see "Procedure:
Understanding the system status using the LEDs" on page 213.
v Verify that the SAS cabling to the expansion enclosure is correctly installed. To
review the requirements, see "Problem: SAS cabling not valid" on page 208.

Problem: Mirrored volume copies no longer identical

The management GUI provides options to either check copies that are identical or
to check that the copies are identical and to process any differences that are found.
To confirm that the two copies of a mirrored volume are still identical, choose the
volume view that works best for you. Select one of the volume copies in the
volume that you want to check. From the Actions menu, select the Validate
Volume Copies option.
You have the following choices:
v Validate that the volume copies are identical.
v Validate that the volume copies are identical, mark, and repair any differences
that are found.
Chapter 5. Control enclosure
209