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9 Dell Storage PS Series Arrays: Scalability and Growth in Virtual Environments | TR1072
4 CHAP authentication for access control
Manipulating MPIO modules and increasing volume sizes are both great ways to manage volume connections
but there are other best practices and recommendations that can also help control how connections are made
to PS Series volumes. CHAP authentication for access control lists can be very beneficial. In fact, for larger
cluster environments, CHAP is the preferred method of volume access authentication, from an ease-of-
administration point of view.
Note: Additional information regarding CHAP can be found in the document, Access Control Policies.
Using CHAP can help improve scalability and ease management. When a new host server is introduced to a
cluster, the administrator needs only to set the CHAP configuration on the iSCSI initiator to enable the new
host access to all of the storage resources of the clusters. When a new volume is created, only one ACL entry
and an initiator rescan is needed for all the cluster host servers to be able access the additional storage
capacity.
Note: In a VMware environment, this also allows rapid movement of datastores between clusters. By simply
unregistering the VMs, changing the ACL, and rescanning, entire volumes or datastores can be moved
between clusters.