Working with autonomic groups, Volume migration (tiering) – HP Matrix Operating Environment Software User Manual

Page 67

Advertising
background image

array, then a presentation request might indicate that the initiator port's host grouping should
change. This could happen if a single host contained two initiator ports and the presentation request
referenced one of the ports but not the other (meaning that the initiator port shouldn't be part of
the host anymore). If these presentation requests would affect presentation for another existing
volume, SPM will not change the array's configuration, resulting in a nonconformant service.
For example: Volume1 is presented to Host1 (WWN1) and SPM requests presentation of Volume2
to Host1 (WWN1, WWN2). Adding an initiator endpoint address to the
StorageHardwareIdCollection associated with WWN1 would mean that Volume1 would be
presented to WWN2, which is a side effect. SPM presentation changes will not generate side
effects.

Working with 3PAR Storage System active VLUNs and VLUN templates

On 3PAR Storage Systems, active VLUNs are the paths through which hosts that have logged on
to the fabric can see a given volume. VLUN templates are similar to “declarations” that volumes
are presented to hosts that are currently unknown to the array (for example, offline hosts). SPM
creates VLUN templates, which become active VLUNs when the host is powered on.
For more information, refer to the 3PAR Storage System user guide.

Working with autonomic groups

Autonomic groups are a unique feature of 3PAR Storage Systems that allow storage administrators
to group volumes, hosts, or virtual domains together. Those groups (also known as sets) allow
batch operations on a collection of objects – for instance, presenting a volume to a set of hosts in
one operation – and provide a level of automation by automatically adjusting the way volumes
are exported when objects are added to or removed from sets. For more information, please refer
to the array user guide.
This version of SPM is not fully compatible with autonomic groups and it is recommended to not
use them on arrays managed by SPM. It is however ok to use autonomic groups within the following
guidelines:

Importing volumes that belong to one or more volume sets is supported. SPM will not reflect
the containment of those volumes in volume sets.

Presenting volumes to hosts that belong to one or more host sets is supported. SPM will not
reflect the containment of those hosts in host sets.

Importing volumes that are presented to one or more host sets is NOT supported: SPM will
not be able to reflect that presentation and doing so will lead to errors and inconsistencies
during requirement binding.

Likewise, using non-SPM tools (e.g. 3PAR GUI or CLI) to present an already-imported volume
to a host set will result in unpredictable behavior during requirement binding.

Volume migration (Tiering)

With 3PAR storage systems, it is common for volumes to be migrated from tier to tier. Volume
migration can be performed manually using the 3PAR GUI or CLI, or it can be automated using
licensed software such as Adaptive Optimization and Peer Motion. Either way, SPM must pick up
on those changes and ensure that the catalog is as up to date as possible. To that end, there are
3 ways SPM will update the catalog to take volume migration into account:

1.

When the storage administrator manually re-syncs a volume, SPM will verify that the parent
pool has not changed. If it has, SPM will either:
a.

Move the volume under the new pool if that pool is managed by SPM.

b.

Put the volume offline if the new pool is not managed by SPM.

2.

During volume discovery for a given pool: SPM will detect volumes already managed by the
catalog that were moved to or from the pool and re-syncs those volumes, thus falling back
into case (1) above.

3.

Periodically, SPM re-syncs all resources in the catalog. When this happens, volume migration
will be detected and handled as described in case (1) above.

Working with 3PAR Storage System active VLUNs and VLUN templates

67

Advertising