Configuring Quorum Disks - Cisco MDS 9216 Configuration Manual

Chapter 4 Managing Back-End Storage
Verify the details of each MDisk group and confirm that each MDisk group has 5 MDisks. VDisks have
Step 9
not been assigned at this point.
switch(svc)# show cluster SampleCluster mdisk-grp
-------------------------------------------------------------------------------
name
-------------------------------------------------------------------------------
finance
marketing
The storage capacity (953 MB) is not an integer multiple of the extent size, the last partial extent is
Note
unused.
To identify the number of free extents for MDisk 1, use the show cluster cluster-name mdisk id
Step 10
command.
switch(svc)# show cluster SampleCluster mdisk id 1
mdisk id 1 is online
MDisk ID 1 (one) is a quorum disk and SVC nodes reserve some storage on the quorum disks for cluster
Note
management.

Configuring Quorum Disks

Quorum disks are used when the cluster loses half of the nodes that make up the cluster. The half of the
cluster that contains the majority of the quorum disks continues to process the I/O transactions. The other
half stops processing the I/O transactions. By establishing quorum disks, you can ensure that both halves
of the cluster do not continue to operate.
Quorum disks are set automatically by the software. You can use the quorum command to overwrite the
system-assigned quorum disk and pick a particular set of managed disks to be a quorum disk. The
managed disk that is currently assigned the quorum index number is automatically set to be a
non-quorum disk.
You can assign one of 3 possible quorum index numbers in any desired order. The quorum index number
ranges from 1 to 3.
We recommend that you set quorum disks on multiple controllers to avoid the possibility of losing all of
Tip
the quorum disks with a single failure.
78-16119-01, Cisco MDS SAN-OS Release 1.3
Capacity
7.56 GB
6.48 GB
Is member of mdisk-grp finance
Controller node WWN is 50:05:07:63:00:c0:9c:f9
Controller port WWN is 50:05:07:63:00:cf:9c:f9, LUN 00:00:00:00:00:00:00:00
Controller port WWN is 50:05:07:63:00:c5:9c:f9, LUN 00:00:00:00:00:00:00:00
Controller serial number is 07B24417
Capacity is 953 MB
Number of free extents is 42
Is quorum disk number 2
free extent number
size(MB) of mdisks of vdisks
7.56 GB 16 5
6.48 GB 16 5
Cisco MDS 9000 Family SAN Volume Controller Configuration Guide

Configuring Quorum Disks

number status
0 online
0 online
4-7