HP Storage Provisioning Manager (SPM) version 2.3 User Guide

Volume Migration With Adaptive Optimization And Peer Motion
With HP 3PAR StoreServ Storage Systems, volumes may be migrated from tier to tier. Volume
migration can be performed manually using the HP 3PAR Management Console or CLI, or it can
be automated using licensed software such as Adaptive Optimization and Peer Motion. In either
case, SPM must detect the changes and ensure that the catalog is updated to reflect the volume
migration. SPM updates the catalog to account for volume migration in the following situations:
• When the storage administrator manually re-synchronizes a volume, SPM will verify that the
parent pool has not changed. If it has, SPM will either:
◦ Move the volume under the new pool if that pool is managed by SPM.
◦ Put the volume offline if the new pool is not managed by SPM.
• 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-synchronizes those volumes, thus falling
back into case (1) above.
• Periodically, SPM re-synchronizes all resources in the catalog. When this happens, volume
migration will be detected and handled as described in case (1) above.
The main side effect of volume migration, particularly when automated, is that the parent pool will
change as mentioned above and the RAID level of the volume may change. As a result, allocated
services that specify ‘UseResource' or ‘RaidLevel' requirements may become nonconformant.
Importing a large number of volumes
The SPM catalog can handle tens of thousands of objects. Importing those objects into the catalog
in the first place, however, can be time consuming. SPM supports importing up to 5,000 volumes
at a time for HP 3PAR StoreServ Storage Systems. While the overall discovery and import time
can vary depending on volume configuration (particularly if they are presented to hosts) and
network latencies, one should count about half an hour to import 5,000 volumes. It is worth noting
that:
1. Subscribed capacity for a pool is calculated as the sum of the subscribed capacity for all
volumes in the pool. This means that re-synchronizing pools containing a large number of
volumes can be time consuming
2. Memory required by SPM during array discovery may increase significantly if there are many
volumes on the array. This may impact performance. If this situation is encountered, it may
be beneficial to provide more memory to the system running SPM.
Renaming CPGs
Renaming a CPG is transparent to SPM 2.3 when an HP 3PAR StoreServ Storage System 3.1.2
is used. But renaming a CPG is not transparent to SPM 2.3 if the HP 3PAR StoreServ Storage
System is older than version 3.1.2.
HP 3PAR StoreServ Storage Systems older than version 3.1.2 uniquely identify CPGs by their name.
While this name is guaranteed to be unique at any given point in time, it is not durable because,
outside of SPM, a CPG can be renamed or worse deleted and replaced by a new CPG carrying
the same name. While renaming CPGs or “recycling” CPG names should be avoided if at all
possible, such event can be remedied manually, using the SPM GUI.
In the event a CPG was renamed, the storage administrator should:
1. Discover and import the renamed CPG (i.e. a pool in SPM terminology), which SPM believes
is new
2. Re-synchronize all volumes in the CPG – This will cause SPM to move all the volumes under
the CPG imported in step (1)
3. Remove the old pool out of the catalog
4. Identify all services that mandate the use of the previously mentioned pool and replace the
specified name appropriately so that the service is conformant again
Volume Migration With Adaptive Optimization And Peer Motion 87