Primary Storage

This blog will focus on features for Distributed Storage customers (Spectrum Virtualize  and Spectrum Accelerate)

Display/Return Volume WWN in CSM GUI and REST Interfaces for automation in auto-provisioning cloud environments

CSM has always displayed a volume's user defined name as well as a full unique name.  When host systems map storage volumes though, most will display the volume using the volume WWN and not the user name or full name.  This has made it difficult for customers to determine which volume mapped on the host is the volume in a CSM session, or to determine which volume should be added to a CSM session. 

Starting in CSM 6.2.11, the volume WWN will now be visible in the GUI as well as returned in the CSM REST api interface.  This can allow external solutions, such as auto-provisioning solutions, to create a volume, map it and then automate the inclusion of that new volume in a CSM session to ensure that the new volume is disaster recovery ready. 

Since not all customers require the volume WWN, the column for this will not show by default.  Customers will need to click on the icon in the upper right hand corner of the Volumes table or the Copy Set table in order to select to unhide the Volume WWN column.  The volume WWN will however display by default in a popups or places in the GUI where the volume details are shown. 

In order to look up the volume in CSM that maps to a volume WWN, you can use the GET /storagedevices/volumes/volwwn/{name} REST query.  This will return the volume including the full name for the volume which can then be used to add/remove copy sets or for other queries. 

RFE 144683

REST API improvements for session level queries

The CSM REST API can be quite helpful for external automation.  As more and more customers begin to automate using the REST API CSM continues to get requests for additional information or changes.  CSM 6.2.11 address two of these requests related to session level queries.

Short List of Sessions - The /sessions query for the rest interface will return information on all of the sessions defined on the server.  This data however includes all the overview data available for each session.  In large environments the amount of data can be quite large which includes details on progress for specific role pairs etc.  In 6.2.11 we added a /sessions/short query that will return a list of all the sessions, but provide only minimal information.  This information includes session name, state, status and a few other values.  Using this query can provide a customer a quick list of the sessions and states the allowing them to call a more detailed query on any specific session they want at a later time.

Return Hardware Consistency Group Names - Starting in 6.2.11 the session queries will now return the hardware consistency group names for Spectrum Virtualize and Spectrum Accelerate storage systems.  While CSM will try to use the CSM session name when creating the consistency group for these session types, it cannot always do so.  But returning the hardware consistency group names a customer or external program can map a CSM session to the relationships on the hardware.

RFE 144776 and RFE 145787

Discover existing Spectrum Virtualize FlashCopy relationships

Traditionally, CSM has not assimilated FlashCopy relationships.  The reason for this is that it becomes difficult for CSM to validate that all volumes in the session were flashed consistently at the same time.  In CSM 6.2.9 though we added a Discover command on FlashCopy sessions for DS8000 relationships.  This Discover command queries the hardware and assimilates any existing relationships without having to reestablish the relationships.  In CSM 6.2.11 the Discover command will now be available for Spectrum Virtualize storage as well.  As with DS8000, customer should be very careful in using the Discover command and only use it for sessions where they know the relationships being assimilated are in fact consistent. 

RFE 144783

The Discover command for Spectrum Virtualize systems behaves in the following ways

• • • The Discover command can be run from the Defined, Prepared, or Target Available state. Defined pairs are set to consistent and Target Available if a relationship is found on the hardware that is part of a consistency group. Note: It is assumed that the relationships are flashed and consistent.
    • Although discovered pairs are set consistent, the session is not able to validate that they are consistent to the time of all other pairs in the session.
    • If a consistency group is not yet established for the session, the Discover command assimilates the consistency group for the first pair found into the session.
    • If the hardware relationship found for a pair is not part of a consistency group, the Discover command fails and error message IWNR2096E is set for the pair.
    • If the hardware relationship found for a pair is not in the correct state (that is, flashed), the Discover command fails and error message IWNR2096E is set for the pair.
    • If the hardware relationship found for a pair is part of a different consistency group than that established for or assimilated into the session, the Discover commands fails and error message IWNR2096E is set for the pair.
    • If the FlashCopy session is set with the Incremental option turned off, even if the Discover command assimilated an incremental relationship, the flash always terminates and reflashes the relationship.

CSM 6.2.11 What’s New Video