System FlashCopy Toolkit Could be a Lifesaver
Frequent, complete backups make disaster recovery easier
In 2007, IBM Lab Services announced a new IBM i toolkit to automate FlashCopy at the full system level and manage the BRMS environments. This offering, the Full System FlashCopy (FSFC) Toolkit, was built leveraging some well-established functions from IBM’s iASP-based Copy Services Toolkit.
When an IBM i is running entirely on external storage—including the load source—performing a FlashCopy of all the disks lets you quickly create a copy of a system. Attaching additional LPAR resources to the new copy of disks and performing key configuration changes to prevent IP and application collisions is all that’s required to IPL the cloned partition.
The components of such an environment are:
- Source disks, which is typically a production partition. In a hardware replication environment, the FlashCopy can be initiated from a controlling LPAR
- Source LPAR resources assigned to the source disks
- Target disks and LPAR resources, which include the disks replicated from the source disks and LPAR resources to run the partition
- DS Unit that manages the external disks. The FlashCopy source and target disks must be in the same DS unit—however, the source disks can participate in another hardware replication operation. The FSFC Toolkit has provisions for a secondary DS
- The primary and secondary HMC Units, which mange the source and target LPAR resources, which can be in separate HMC units
- A controlling LPAR, which provides all the communication to the storage, the HMC, and source and target LPARs. IP access is the only requirement. It doesn’t have to be on external disk
The primary reason most users create an identical second LPAR is to perform backups with minimal impact to their production LPAR. It can be used for other purposes, such as development or quality analysis, testing migrations or code updates, PTF levels, or to provide a source for data mining. Some have also used it to create pre-batch snapshots.
The process of creating a full system point-in-time image can be complex, involving many steps and coordinating activities between the source and target systems, the storage and the BRMS or save functions. The FSFC Toolkit was designed to simplify this process and provide you with a single command to accomplish the procedure and mask the complexities. This provides a more stable and consistent process that can be reliably duplicated each night to facilitate your backup operations. For most customers this can be scheduled and performed unattended.
It’s important to recognize that the FSFC Toolkit wasn’t designed to be a high-availability solution. Rather, it focuses on the disaster-recovery aspect by helping you perform backups. Minimizing the impact of backups on the production partition will enable more frequent and more complete backups.
The FSFC Toolkit has some requirements. Most importantly, the source and target LPARs must be running entirely on external disks in an IBM DS8000 or IBM DS6000 storage unit, including the load source.
Starting with IBM i 6.1, the FSFC Toolkit supports creating the FlashCopy disks without powering down the source LPAR. For earlier releases, IBM recommends an IPL but supports warm flashes for test purposes.
If you’re using BRMS, the source LPAR shouldn’t perform any backups until the target LPAR has finished its own backups.
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