A host can be created with worldwide port names (WWPNs)
or iSCSI names. The WWPN name space and the iSCSI name space within SAN Volume Controller share
the same internal SAN Volume Controller resources.
As more iSCSI names are used in host objects, the number of fibre-channel
WWPNs that can be used reduces. Similarly if a large number of fibre-channel
WWPN-based host objects are used, a smaller number of iSCSI hosts
can be defined. The iSCSI name in a host object can take up to a maximum
equivalent of four WWPNs depending on the number of I/O groups that
the host participates in. This affects the maximum number of hosts
that you can configure in a SAN Volume Controller cluster.
Each SAN Volume Controller I/O
group can have up to 512 WWPN entries. Assuming, for example, that
a host is created by using a single iSCSI IQN, the maximum number
of hosts (X) that participate in multiple I/O groups (Y) can be calculated
by using X < = 512 / Y.
To create iSCSI hosts with a single iSCSI name in a single
I/O group (I/O group 0), enter the following command-line interface
(CLI) command:
svctask mkhost -iscsiname iscsi1 -iogrp 0
- A maximum of 256 iSCSI hosts can be created in I/O group 0.
- A mix of up to 256 fibre-channel and iSCSI-based hosts can also
be created in I/O group 0.
- An additional 256 fibre-channel or iSCSI-based hosts can be created
in I/O groups 1, 2, and 3.
- The total number of hosts for the cluster is 1024.
To create a host with a single iSCSI name in two I/O groups,
enter the following command:
svctask mkhost -iscsiname iscsi1 -iogrp 0:1
- Up to 256 iSCSI hosts can be created in I/O groups 0 and 1.
- An additional 256 fibre-channel or iSCSI hosts can be created
in I/O group 2.
- An additional 256 fibre-channel or iSCSI hosts can be created
in I/O group 3.
- The total number of hosts for the cluster is 768.
To create a host with a single iSCSI name in three I/O groups,
enter the following command:
svctask mkhost -iscsiname iscsi1 -iogrp 0:1:2
- A maximum of 170 hosts can be created in I/O groups 0, 1, and
2.
- An additional 256 fibre-channel hosts or iSCSI hosts can be created
in I/O group 3.
- The total number of hosts for the cluster is 426.
To create a host with single iSCSI name in four I/O groups,
enter the following command:
svctask mkhost -iscsiname iscsi1
- A maximum number of 128 hosts can be created in the four I/O groups,
which means 128 total iSCSI hosts for the cluster versus 256 fibre-channel
hosts.
- The maximum number of hosts can be created in I/O groups 0, 1,
2, and 3.
- The total number of hosts for the cluster is 128.