Technical data

System Management Release Notes
5.9 OpenVMS Cluster Systems
5.9.17 Multipath Failover Fails Infrequently on HSZ70/HSZ80 Controllers
V7.2-1
Under heavy load, a host-initiated manual or automatic path switch from one
controller to another may fail on an HSZ70 or HSZ80 controller. Testing has
shown this to occur infrequently.
Note
This problem has been corrected for the HSZ70 in the firmware revision
HSOF V7.7 (and later versions) and will be corrected for the HSZ80 in a
future release. It does not occur on the HSG80 controller.
5.9.18 SCSI Multipath Incompatibility with Some Third-Party Products
V7.2
OpenVMS Alpha Version 7.2 introduced the SCSI multipath feature, which
provides support for failover between the multiple paths that can exist between a
system and a SCSI device.
This SCSI multipath feature may be incompatible with some third-party disk
caching, disk shadowing, or similar products. Compaq advises you to avoid the
use of such software on SCSI devices that are configured for multipath failover
(for example, SCSI devices that are connected to HSZ70 and HSZ80 controllers
in multibus mode) until this feature is supported by the manufacturer of the
software.
Third-party products that rely on altering the Driver Dispatch Table (DDT) of
the OpenVMS Alpha SCSI disk class driver (SYS$DKDRIVER.EXE) may require
changes to work correctly with the SCSI multipath feature. Manufacturers
of such software can contact Compaq at
[e-mail] for more
information.
For more information about OpenVMS Alpha SCSI multipath features, see
Guidelines for OpenVMS Cluster Configurations.
5.9.19 Gigabit Ethernet Switch Restriction in an OpenVMS Cluster System
V7.3
Attempts to add a Gigabit Ethernet node to an OpenVMS Cluster system over a
Gigabit Ethernet switch will fail if the switch does not support autonegotiation.
The DEGPA enables autonegotiation by default, but not all Gigabit Ethernet
switches support autonegotiation. For example, the current Gigabit Ethernet
switch made by Cabletron does not.
Furthermore, the messages that are displayed may be misleading. If the node
is being added using CLUSTER_CONFIG.COM and the option to install a local
page and swap disk is selected, the problem may look like a disk-serving problem.
The node running CLUSTER_CONFIG.COM displays the message ‘‘waiting for
node-name to boot,’’ while the booting node displays ‘‘waiting to tune system.’’
The list of available disks is never displayed because of a missing network path.
The network path is missing because of the autonegotiation mismatch between
the DEGPA and the switch.
System Management Release Notes 5–21