DFSMS SDM Copy Services

• z/OS Global Mirror, also known as Extended Remote Copy (XRC)
• Peer-to-Peer Remote Copy (PPRC) including:
  • Metro Mirror, also known as synchronous PPRC
  • Global Copy, also known as PPRC-XD
  • Global Mirror
• 3-site solutions:
  • Metro/Global Copy
  • Metro/Global Mirror (M/GM)
  • Metro/zGlobal Mirror (M/zGM)
• FlashCopy®
• Concurrent Copy
• Virtual Concurrent Copy
• SnapShot®

Features

• Provide a comprehensive disaster recovery solution for the z/OS environment.
• Deliver a range of data duplication solutions that solve the customer requirement for an immediate point-in-time copy of data.
• SDM provides TSO commands and the ANTRQST API to enable disk hardware copy services functions.

Application benefits

	Extended Remote Copy (XRC) - XRC addresses the problem of unrecoverable data that occurs between the last, safe backup of a primary system to a recovery system and the time when the primary system fails. XRC provides an asynchronous copy operation, over distance, with minimal performance impact to primary system DASD I/O write operations. XRC supports zSeries® attached (count key data, or CKD) devices. This includes data running on z/OS, z/VM® and Linux®. XRC functions can be dispatched on a zIIP processor if one is available.
	Peer-to-Peer Remote Copy (PPRC) - Like XRC, Peer-to-Peer Remote Copy (PPRC) addresses the problem of unrecoverable data that occurs between the last, safe backup of a primary system to a recovery system and the time when the primary system fails. PPRC offers both synchronous and asynchronous copy functions for the primary volume’s I/O operation. Metro Mirror is offered for mirroring volumes at local distances.  Global Copy is offered for copying volumes long distance or for migrating data.  Global Mirror is offered for mirroring volumes at extended distances.  PPRC supports both zSeries attached (CKD) devices and Open System (fixed block, FB) devices.
	FlashCopy - The FlashCopy function provides a point-in-time copy of data for backup and recovery operations. FlashCopy creates a Time 0 (T0) copy of a volume or set of tracks. The T0 copy is current with the volume or set of tracks at the time that the action is initiated. Subsequent updates to the original volume or set of tracks are not reflected in the T0 copy. FlashCopy allows you to copy individual tracks and create multiple relationships. The target tracks for a FlashCopy request can be on the same volume as the source, or any other volume within the same storage facility image. FlashCopy allows you to copy only critical data instead of an entire volume, and it allows the copies from multiple source volumes to share the same target volume. FlashCopy supports both zSeries attached (CKD) devices and Open System (FB) devices.
	3-site solutions - The Metro/Global Copy and the Metro/Global Mirror functions allow you to cascade a PPRC pair with a PPRC-XD pair such that the PPRC secondary also serves as the PPRC-XD primary. In this configuration, a primary and secondary pair is established with the secondary located in a nearby site, protected from primary site disasters. The Global Copy or the Global Mirror secondary volume could be located thousands of miles away and would continue to be updated if the original primary location suffered a disaster.  The Metro/zGlobal Mirror function allows you to have a PPRC relationship and an XRC relationship from the same primary volume.  The PPRC relationship protects at a local distance from primary site disasters, and the XRC relationship can be restarted from the PPRC secondary for long distance protection in the event of a primary site outage.
	SnapShot - SnapShot is a function of RAMAC® Virtual Array (RVA) storage subsystems that allows you to make a very quick copy of a set of tracks (an entire volume, a data set, or just a random set of tracks). The copy operation is completed with only a few I/Os to the device. SnapShot supports zSeries attached (CKD) devices
	Concurrent Copy (CC) - Concurrent copy is an extended function that enables data center operations staff to generate a copy or a dump of data while applications are updating that data. Concurrent copy delivers a copy of the data, in a consistent form, as it existed before the updates took place.
	Virtual Concurrent Copy (VCC) – Virtual Concurrent Copy is an extended function that performs Concurrent Copy utilizing FlashCopy. In VCC data is flash-copied from the source location to an intermediate location and then gradually copied to the target location using normal I/O methods.