HP StorageWorks 2000 Series Reference Manual page 211

Making a configuration or cabling change on a host might cause the storage system
to stop accepting I/O requests from that host. For example, this problem can occur
after moving host cables from one HBA to another on the host. To fix such a
problem you might need to reset controller host ports (channels). For a Fibre
Channel host port configured to use FC-AL (loop) topology, a reset issues a loop
initialization primitive (LIP). For a SAS host port, a reset issues a
To reset a host port, as an Advanced Manage user:
1. Select Manage > Utilities > Host Utilities > Reset Host Channel.
2. Select the controller and host port.
3. Click Reset Host Channel.
PHY lanes are the physical signal paths used for communication between the SAS
expander in each controller module and the drive modules in a system. The
Expander Controller in each controller module automatically monitors PHY error
(fault) rates and isolates (disables) PHYs that experience too many errors.
The Expander Isolation page is similar to the Expander Status page, but enables you
to reset expander error counters, manually disable or enable individual PHYs, and
disable or enable PHY fault isolation.
Use of the Expander Status page is described in "Checking PHY Status" on
page 206 and in "Expander Status" on page 167.
If PHYs have errors, you can reset expander error counters and then observe error
activity during normal operation. If a PHY continues to accumulate errors you can
disable it in the Expander Controller Phy Detail panel.
To reset expander error counters:
In the Clear Expander Errors panel, click Clear Errors.
sequence.