Mainframe Storage

In December 2020 IBM GA'd a new version of IBM Copy Services Manager 

Copy Services Manager 6.2.11 Download

As always, we're very excited to provide the following key features being released in this new version.  We develop Copy Services Manager in an agile development cycle and as such have included a number of customer requested features!!!

This blog will focus on features for mainframe customers (DS8000 and z Attached customers)

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.

New Migration session type is now available for no charge on CSM DS8000 HMC installations

In CSM 6.2.10 a new session type was added that only allows a customer to Start the session in Global Copy mode.  Since this session does not guarantee consistency at the remote site in the event of a disaster, the intent of this session is to provide customers the ability to migrate data between DS8000 volumes using Global Copy relationships. 

In 6.2.10 this solution required a full CSM license, however, in 6.2.11, this solution will now be available as part of the no charge license on every DS8000 HMC where CSM is pre-installed (all DS8000 8.1 and above systems have CSM pre-installed).  This provides a straight out of the box solution for all DS8000 customers without the need to purchase an additional CSM license. 

The availability of this solution is similar to the support CSM provides for LDAP enablement of older DS8000 systems that do not have native LDAP enablement.  If an issue occurs with the Migration session, open a ticket on the DS8000 product to ensure you receive proper support, as opposed to the CSM product. 

Allow usage of CSM backup files when migrating a CSM server to a z/OS system

In the CSM 6.2.9 release, the backup feature for CSM servers was enhanced to include ALL files necessary to either migrate or restore a CSM server. Previously only the database containing the connection and session information was collected. Now all necessary properties and changes are collected.  However, using the backup file on z/OS installations required manually unzipping and managing the contents of the zip file.

Starting with CSM 6.2.11 you can now use the backup zip file for CSM during a z/OS installation in order to migrate an existing CSM server to z/OS. The backup zip can be created on a Distributed or another z/OS system.

Migration using the backup zip file can be done by using the existing MIGRATE_FROM value in the IWNINSTL script on z/OS and specifying the zip file instead of a location.

MIGRATION_FROM=/tmp/csmBackup_<date_stamp>_<time_stamp>.zip

NOTE: The path also needs to be set with read access by the user that submits the IWNINSTL job.

RFE 141749

View LSS OOS historical statistics graphically in the CSM GUI

In the CSM 6.2.10 release, CSM added the ability to view DS8000 Global Mirror historical RPO data within a chart in the GUI.  Starting with CSM 6.2.11, you can now also view the LSS OOS historical statistics for given LSS and role pairs within a session.  When customers see higher than usual RPO in the RPO charts, they can now bring up the LSS OOS statistics charts for the same time frame in order to determine whether one or more LSSs had high levels of OOS.  High levels of OOS on an LSS can cause the DS8000 to fail to form consistency groups and lead to higher than expected RPO times.  This new chart can help a customer further debug why their RPO might be higher than their expected thresholds.

To view the LSS OOS click on Session Actions->View Modify->Global Mirror data and then click on the LSS Graph tab on the left side of the graph.  You can choose the timeframe to display using the slider at the bottom and choose which LSSs to display using by clicking on the left side of the graph to slide out the LSS selector.

RFE 84717

Support CSM IP to z/OS host connections to multiple sysplexes or monoplexes with the same name

In previous releases CSM could not manage multiple systems with the same name because when you went to associate a sysplex to a session for HyperSwap or Hardened Freeze support, there was no way to distinguish which session to associate.

Now in CSM 6.2.11, the drop down in session properties will display the sysplex as a concatenation of the sysplex name and the hostname defined in the connection to z/OS.  This allows a customer to distinguish which of the sysplexes should be tied to a given session.

RFE 139998

New option on DS8000 FlashCopy and Practice session to fail flash if target is online to a host

In previous releases CSM allowed customers to fail the flash for an FlashCopy session role pair by specifying a property in the server properties file.  Starting with CSM 6.2.11, an option will now be displayed under View Modify->Properties for all supported sessions. 

The property is disabled by default but when specified, if the target volume is a CKD volume and is online to a host system, any flash to that volume will fail.  

NOTE: In order to not break customers that currently have the fail on flash set in the server properties file, the server properties file will override the property set in the CSM GUI.  Customers should select the option in the GUI and remove the property from the server properties when possible, to avoid confusion.

The following sessions support the new property

FlashCopy
Global Mirror Failover/Failback w/ Practice
Metro Mirror Failover/Failback w/ Practice
Global Mirror Either Direction w/ Two Site Practice
Metro Global Mirror w/ Practice
Metro Mirror – Global Mirror w/ Practice

RFE 112978

New session type designed to help customers more accurately size for Safeguarded Copy and FlashCopy solutions

In CSM 6.2.11 a new session is available.  The ESEsizer session supports analyzing space requirements for DS8000 Extent Space Efficient (ESE) FlashCopy and Safeguarded Copy environments.

An accurate sizing of ESE FlashCopy and Safeguarded Copy is crucial. With the DS8880 microcode release 8.5.4 and DS8900F release 9.1 a Write Monitoring (WM) bitmap was implemented in the DS8000 to track all write to each volume.  The purpose of the Write Monitoring Bitmap is to provide an effective way to determine usable space requirements for both Extent Space Efficient (ESE) FlashCopy and Safeguarded Copy without impacting host write I/O or disk replication performance. The write monitoring bitmap enables a DS8000 to track the amount and locality of its changed data over definable time intervals and across a set time period in an existing production environment.

The new session type queries the Write Monitoring bitmap and provides output files on box and volume level. Those output files contain the currently allocated extents, changed tracks, changed small extents and change large extents. That level of detail can readily be used to determined how much capacity would have been allocated over time for both functions ESE FlashCopy and Safeguarded Copy.

The ESEsizer session can start, stop and reset the WM bitmap. With the available properties you can define the volume query interval and the bitmap reset interval.

To interpret the data collected a tool will soon be available online that will allow you to import the csv files collected from the session.  If assistance is necessary please contact lab services or Washington Systems Center.

Performance enhancements for Safeguarded Copy and FlashCopy in mainframe environments

In order to create consistent FlashCopy flashes and Safeguarded Copy backups, a freeze must be issue briefly across all volumes in the session during the flash or backup process.  While CSM has implemented a number of enhancements in previous release to minimize the application impact of the freeze, network and system resources for the CSM server can impact the overall performance thus making it hard to achieve the flash and backup times of mainframe solutions like CSM FCM or GDPS. 

In CSM 6.2.11, customers can now go into the properties for a FlashCopy or a Safeguarded Copy session and associate the session with a sysplex. When a sysplex is associated, the necessary commands are passed down to the IOS component on z/OS to perform the flash or backup, dramatically improving the performance and minimizing application impact.

In order to use the feature, all volumes in the session must be attached to the zOS system that is associated to the session. If the volumes are not attached the backup or Flash will fail, and the sysplex association will need to be removed so that the flash or backup can be executed the traditional way.

NOTE: IOS APAR OA59561 must be applied to the z/OS system you associate with the session for the new solution to work.  If the the APAR is not applied the flash or backup will result in an error. 

While the solution doesn't replace all of the features of CSM FCM, customers may want to consider using this new CSM solution for their FlashCopy relationships to see if the performance now meets their requirements.

It is highly recommended that any customers looking to backup or flash production volumes in a mainframe environment use this solution. 

CSM 6.2.11 What’s New Video

RFE support for Copy Services Manager