HP MSA 2040 SAN Storage - Manual (Page 21)

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4 Best practice recommendations
Specific recommendations for using HP MSA SRA 5.0 or later and Remote Snap software in conjunction
with the VMware SRM disaster recovery solution include the following:
• Prepare a plan ahead of time for how you will re-establish replication schedules in the event of a site
failover. After performing a reverseReplication operation, the user must set up replication schedules in
order to ensure periodic replication of data from the new source volumes back to the original source
site. Alternately, you can initiate replication manually if appropriate.
• Try to group virtual machines with related backup requirements or schedules on the same datastore
volume, since replication occurs on a per-volume basis. For example, if some virtual machines do not
need to be replicated to a remote site, or need to be replicated less frequently, do not store them on the
same datastore volume as virtual machines which must be replicated frequently, to avoid replicating
data unnecessarily.
• Each array must have a unique alphanumeric “System Name” assigned which does not use any
non-alphanumeric characters other than “.” or “-”. No spaces are allowed in the system name.
• Each array must have remote systems defined for each of the remote arrays to or from which data is
being replicated. The SRA depends on these remote system names being defined for basic
functionality.
• The SRA only supports replication between identical hardware models. For example, replication
between an iSCSI-only system and a FC/iSCSI Combo system is not supported.
• Avoid mapping replication volumes to LUN 0 to avoid issues with dynamically mapping and
unmapping LUNs, due to special management functionality assigned to LUN 0. You can map volumes
to LUN 0 if those volumes are not expected to be mapped and unmapped automatically the way
replication volumes are, such as local datastores that are not replicated.
• Replication volumes should be mapped with the same LUN number on all hosts.
• Do not use the same LUN number for different volumes that are mapped to different hosts.
• Failover operations will cause read-write host mappings for replication volumes to be converted to
read-only, and restoring replication will convert all read-only mappings for the same volume to
read-write. Be careful not to create read-only mappings of replication volumes such as for data mining
purposes. If a read-only mapping of a replication volume is required, consider creating a
non-replicated hardware or software snapshot of the volume.
• The SRA might create host entries on the array to keep track of remote IP or FC addresses. Do not
delete host entries whose name starts with “SRA.”