Use multipathing to provide network and controller redundancy for the iSCSI data path between the NetApp Cluster-mode SAN and NCs.
Important: Eucalyptus supports multipathing for NetApp Clustered ONTAP only.
Important: It is strongly recommended that you get your system up and
running and able to create volumes and snapshots using the NetApp SAN prior to
configuring multipathing. Multipathing can be configured after the cloud is fully
functional and will apply to any volumes attached/snapshotted after multipathing is
configured. Configuring multipathing on a non-multipathed system does not require a
restart of the SC, NC, or CLC.
To configure multipathing for a NetApp SAN:
Ensure that the mutipathd service is running on the SC and on each NC:
Configure the /etc/multipath.conf file.
Note: An example configuration for NetApp is installed with Eucalyptus. This
file is located in
on each NC.
Start the mutipathd service:
If you modify the /etc/multipath.conf file, be sure to
restart and reconfigure multipathd:
Restart the multipathd service:
service multipathd restart
Run multipathd -k:
Enter the following commands at the multipathd
Check that the multipath udev rules file is installed by
verifying that the file
Set the ISCSI paths:
Note: The path specification format is
iface0:ip0,iface1:ip1,...,ifaceN:ipN where iface may be
re-‐used (i.e. multiple iface0 entries). Also, note
that ‘iface’ is optional, you may just specify a
comma-‐delimited list of IPs. Eucalyptus will detect
which interfaces on the SC/NC can reach each specified
IP and will use the first found. You must only specify
the ‘iface’ value if you want precise control over which
interfaces access which IPs. For using a single path
only, just specify the IP of the iscsi data port to use
on the NetApp Clustered ONTAP.
Note: We recommend initially getting the system working with only one path. The
path values can be modified at any time to enable multipathing, so it is
possible to get everything working and confirm full NetApp functionality
before attempting multipathing. To use one path, simply specify a single IP
for each the following steps.
Set the NC paths. For example:
Set the SC paths. For example:
Note: The NC and SC may each have different path
lists, or you can optionally only enable
multipathing on the NCs or SC if desire.
If you specified an iface when
setting the SC paths, be sure to include a line in
the eucalyptus.conf file of each NC in the cluster
that defines each iface. For
Test and verify the configuration by creating (and
attaching to) a volume and creating a snapshot on the
If testing is successful, you can now configure multiple
paths in your *.storage.ncpaths and *.storage.scpaths
Verify that multipathing is working on the SC and on an NC by attaching a
volume to an instance on the SC and the NC and running the following command:
This command should return output similar to the
mpathp (3600a098037542d69535d43514965354e) dm-2 NETAPP,LUN C-Mode
size=2.0G features='3 queue_if_no_path pg_init_retries 50' hwhandler='1 alua' wp=rw
|-+- policy='round-robin 0' prio=50 status=active
| |- 18:0:0:0 sdd 8:48 active ready running
| `- 20:0:0:0 sdf 8:80 active ready running
`-+- policy='round-robin 0' prio=10 status=enabled
|- 17:0:0:0 sdc 8:32 active ready running
`- 19:0:0:0 sde 8:64 active ready running
You have now successfully configured multipathing for your NetApp Clustered ONTAP system.