Use the Viewing Quorum Disks panel in the SAN Volume Controller Console to
display a list of managed disks (MDisks) that are used as quorum disks
for the cluster.
Introduction
A quorum is
set of nodes that operates as a cluster. Each node has a connection
to every other node in the cluster. If a connection failure causes
the cluster to split into two or more groups of nodes that have full
connection within the group, the quorum is the group that is selected
to operate as the cluster. The cluster supports three MDisks as quorum
disk candidates. Each disk is assigned an number, either 0, 1, or
2, called a quorum index, that identifies the MDisk as a quorum disk
to the cluster. You can also assign one of the quorum disks to be
the active quorum disk, which is used to resolve a tie-break situation.
There can only be one active quorum disk at a time.
Attributes
The
following attributes are displayed:
- Select
- Allows you to select an MDisk to use to perform an action from
the task list.
Note: Only one row can be selected at a time.
- Name
- Displays the name of the MDisk.
- State
- Displays the state of the MDisk. The following values are possible:
- Online
- Indicates the MDisk is online and available. All paths to the
MDisk are available.
- Degraded Paths
- Indicates that the MDisk is not accessible to one or more nodes
in the cluster. Degraded path state is most likely the result of incorrect
configuration of either the disk controller or the fibre-channel fabric.
However, hardware failures in the disk controller, fibre-channel fabric,
or node could also be a contributing factor to this state. Complete
the following actions to recover from this state:
- Verify that the fabric configuration rules for storage systems
are correct.
- Ensure that you have configured the storage system properly.
- Correct any errors in the error log.
- Degraded Ports
- Indicates that one or more 1220 errors have been logged against
the selected MDisk. The 1220 error indicates that the remote fibre-channel
port has been excluded from the MDisk. This error may cause reduced
performance on the storage controller and usually indicates a hardware
problem with the storage controller. To fix this problem you must
resolve any hardware problems on the storage controller and fix the
1220 errors in the error log. To resolve these errors in the log,
select . On
the Maintenance Procedures panel, select Start Analysis.
This action displays a list of unfixed errors that are currently in
the error log. For these unfixed errors, select the error name to
begin a guided maintenance procedure to resolve these errors. Errors
are listed in descending order with the highest priority error listed
first. Highest priority errors should be resolved first.
- Excluded
- Indicates the MDisk has been excluded from use by the cluster
after repeated access errors. Run the directed maintenance procedures
to determine the problem. You can reset an MDisk and include it in
the cluster by running the include task.
- Offline
- Indicates the MDisk is offline and unavailable. All paths to this
MDisk have been lost.
- Quorum Index
- Displays the number that is assigned to this quorum disk. The
number can be either: 0, 1, or 2. You can assign an MDisk a specific
index number or the system can assign one.
- Active
- Displays whether
the quorum disk is the active quorum disk. The active quorum disk
is the disk which is used first in the event of a cluster partition.
You should set an active quorum disk when nodes in an I/O group are
split between different physical locations to ensure that the most
highly-available quorum disk is used.
- The following
values are possible:
- Yes
- Indicates that the quorum disk is used first in the event of a
cluster partition.
- No
- Indicates that the quorum disk is not used first in the event
of a cluster partition.
- MDisk Group Name
- Displays the name of the MDisk group that this quorum disk is
assigned to.
- Controller
- Displays the name of the disk controller system that contains
the quorum disk.
Actions
You
can select one of the following tasks from the task list:
- Set a Quorum Disk
- Set Active Quorum Disk
Note: With the exception of the Set a Quorum Disk task,
you must first select an MDisk before you can select a task.
- Go
- Click this button after selecting a task from the task list. Clicking Go launches
the panel for the task that you selected.
- Refresh
- Click this button to refresh the table with changed values.