Explanation
The single point of failure service has detected
that all paths to volume vvvvvv share components such as host adapter
or host port on the control unit.
In the message text:
- vvvvvv
- The volume with the single point of failure.
- sdddd
- The subchannel set and device number of the device with a single
point of failure.
- d1
- The number of shared components in the control unit interface.
- d2
- The number of possible shared components in the control unit interface.
System action
The system continues processing.
Operator response
System programmer response
There are 4 model dependent hardware
redundancy levels that are obtained from the control unit by the software.
An error message for a given level means that there are two or more
channel paths that are configured through the same hardware component
on a given level.
Because the common components are model dependent,
consult your H/W reference material or H/W support to determine what
the single point of failure is.
The following example is for
the IBM® DS8000® control unit:
The 4 common component
levels reported for the DS8000 control
unit are presented here in hierarchical order. In other words, a single
point of failure citing 1 of 4 components means that the single point
of failure is with the first level only. 2 of 4 means that the single
point of failure is with the second level and the first level, and
so on.
DS8000 single
point of failure common component levels:
- Level
- Description
- 1
- All interfaces are to enclosures in the same rack. If your control
until has more than one rack, consider configuring channels to enclosures
in different racks.
- 2
- All interfaces are to a single set of odd/even enclosures. For
example, all interfaces go to enclosure 0 and 1, or 2 and 3, and so
on. If more than one odd/even enclosure pair exists, consider configuring
channels to different odd/even enclosure pairs.
- 3
- All interfaces are to the same enclosure. If multiple enclosures
exist, consider configuring channels to different enclosures.
- 4
- All interfaces are to the same host adapter card. If multiple
host adapter cards exist, consider configuring channels to different
adapter cards.
Note: Based on the configuration, it is possible that
a single point of failure is expected. For example, control units
that have only a single rack might report a single point of failure
existing because all channels are configured to the same rack. In
this case, the single point of failure message can be ignored.
Source
Module