Backing up data sets to an object storage cloud

DFSMSdss can create logical data set backups to an object storage cloud when the following requirements exist:
  • The source device is in a storage controller that supports transparent cloud tiering.
  • The source device is in a storage controller that is connected to an object storage cloud.
  • The storage controller and z/OS host are both connected to the same object storage cloud.
  • The data must not need manipulation. The following types of processing require data manipulation:
    Reblocking
    Reblocking occurs when you specify the REBLOCK keyword or when the VTOC indicates that the data set can be reblocked. The REBLOCK keyword and the indicator in the VTOC is ignored when a backup is being restored from an object storage cloud.
    PDS compression
    DFSMSdss compresses a PDS data set during backup processing, by default. You can specify the NOPACKING keyword to prevent DFSMSdss from compressing the PDS. There is no special action needed in order to backup a PDS to an object storage cloud. When creating a backup to an object storage cloud, DFSMSdss operates as if NOPACKING(**) is specified.
    Changing stripe counts
    The source stripe count must be the same as the target stripe count for a striped extended format data set. When restoring a backup from an object storage cloud, DFSMSdss ensures the stripe count does not change. If a data set cannot be created with the same amount of stripes the allocation will fail and the data set will not be restored.
    An individual stripe extending to more than one volume
    DFSMSdss cannot backup striped VSAM data sets when one or more of the stripes spans volumes. DFSMSdss also cannot backup a single striped version 1 extended format sequential data sets that is multivolume.
    Block-by-block processing of direct access data sets
    Block-by-block processing occurs when you specify the RELBLOCKADDRESS OR the AUTORELOCKADDRESS keyword. When restoring a backup from an object storage cloud, DFSMSdss operates as if RELBLOCKADDRESS and AUTORELBLOCKADDRESS are not specified.

Designating cloud as a backup target

The CLOUD(cloud_name) keyword tells DFSMSdss that the backup is to be directed to an object storage cloud by the name of cloud_name. A cloud construct called cloud_name must exist in the active SMS configuration. DFSMSdss uses the construct to obtain the information necessary to make a connection to the object storage cloud. When the CLOUD keyword is specified the following keywords must also be specified:
  • CONTAINER
  • OBJECTPREFIX
  • CLOUDCREDENTIALS

The CONTAINER(container_name) specifies the container in which the objects are to be stored. The container specified as input does not have to exist at the time of the backup. If necessary, DFSMSdss will create it for you.

The OBJECTPREFIX(object_prefix) specifies a unique prefix that DFSMSdss is to use for all of the objects the make up a particular backup. The prefix provides uniqueness amongst multiple backups in the same container. At the beginning of the backup process, DFSMSdss will determine if a backup using the same object_prefix already exists in the specified cloud_name and container_name. If a backup already exists with the same object_prefix then DFSMSdss will fail the backup. If you wish to overwrite a backup using the same object_prefix you can set a patch at offset x'5D'. The CLOUDCREDENTIALS(cloud_credentials) specifies the password for the account that is defined within the cloud construct. This password is case sensitive and is suppressed from SYSPRINT and SVCDUMPs. The cloud credentials must be kept secure. If there are batch JCL jobs that specify this keyword, then those jobs should be in a data set or library that has limited access and controlled by a security product. If the credentials cannot be kept secure then this keyword should not be used.

Restrictions:
  • DFSMSdss does not set any expiration dates on objects created in cloud storage. It is up to the user to manage expiration of backups manually.
  • Objects in cloud storage are not cataloged therefore it is up to the user to manage the location (cloud, container and object prefix) manually.
  • The cloud credentials must be kept secure. If there are batch JCL jobs that specify this keyword, then those jobs should be in a data set or library that has limited access and controlled by a security product. If the credentials cannot be kept secure then this keyword should not be used.
  • Since the DS8000 only supports a single account, it is recommended that using both DFSMShsm and DFSMSdss for the same account should only be done in a test environment. DFSMSdss and DFSMShsm should not share a single account in a production environment.

Invocation from an application program

Application programs can direct the DFSMSdss DUMP command to target an object storage cloud. UIM exit points 31, 32 and 33 are designed to aid application programs using DFSMSdss to create backups in an object storage cloud.

Applications can control the where the z/OS Web Enablement Toolkit serviceability information is directed using UFO_ZWEBT_DD in the ADRUFO Installation Exit. The default where serviceability information is issued to is SYSPRINT. For more information about the installation options exit, refer to z/OS DFSMS Installation Exits.