DFSMSdss
DFSMS data set services: the z/OS program for copying, moving, backing up and restoring datasets and whole volumes.
Also written ADRDSSU, DSS, DUMP and RESTORE, volume backup
DFSMSdss, usually called DSS, is the z/OS tool for moving data in bulk. The program that runs it is ADRDSSU, a name you will see in many storage jobs.
Its main commands are DUMP, which backs up datasets or whole volumes to a dataset, often on tape; RESTORE, which brings them back; COPY, which copies datasets or volumes from one place to another; and DEFRAG, which tidies the free space on a volume. Datasets can be chosen with name patterns, such as every dataset starting ZBANK.PROD, and filters such as how recently they were changed.
It can work logically, dataset by dataset, or physically, track by track for a whole volume. When the disk system supports it, DSS uses FlashCopy to make copies almost instantly.
Storage administrators use DSS for backups, for moving data to new disks and for disaster recovery preparation. DFSMShsm also uses it behind its own backup and migration functions. As a developer, you might use a simple DSS job to back up your own datasets before a big change.
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Right here, at ZedBank. You take a junior job at a simulated bank and learn each part of the work by doing it, with Zed beside you. There's nothing to install.
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- DFSMShsmThe z/OS storage manager that moves datasets you have not used for a while to cheaper storage, and brings them back when you need them.
- FlashCopyA feature of mainframe disk systems that makes an almost instant copy of a dataset or volume, as it was at one moment.
- DASDDirect access storage device, the mainframe term for disk storage.
- VolumeA single unit of disk storage with a six-character label, on which datasets are placed.
- Disaster recoveryThe plans, copies of data and second systems that let an organisation keep running if a whole data centre is lost.
- SMSThe Storage Management Subsystem: the z/OS feature that decides where new datasets go and how they are backed up, kept and deleted, using rules the site writes.