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Mainframe - FlashCopy Implementation
This article explains using FlashCopy to create a snapshot of a production disk volume and an offline volume for backups.
FlashCopy allows us to establish a relationship between a Production disk volume and an offline (“Target”) volume. This relationship allows a “snapshot” of the Production data to be copied to the Target volume. Updates can be made to the Production data without affecting the data being copied to the Target volume.
We establish a FlashCopy relationship between Production and Target disks every Monday through Saturday morning at 4:00 AM and every Sunday morning shortly after Midnight. This procedure takes no more than a few minutes. Once the FlashCopy relationship has been established, Computing Partners may update data on the Production volumes without affecting the data being transferred to the Target volumes. If a Production volume file is selected for update before it has been copied it will immediately be copied to the Target volume before the update is processed.
FlashCopy Incremental Backups
On Monday through Saturday Midnight Shifts following the establishment of the FlashCopy relationships we run Incremental Backups against the Target disks without interfering with users’ ability to access and update their data on Production volumes. Following completion of the Incremental Backups, we will IPL the LPAR using the Target disks.
FlashCopy Full and Offsite Backups
Starting on Sunday Midnight Shifts and continuing during Sunday Day (and Evening if needed) Shifts, we run Full and Offsite Backups against the Target disks without interfering with users’ (or Production’s) ability to access and update data on Production volumes. We need to keep the UCHIBETA LPAR down on Sundays to accomplish this.
On those rare weekdays when Production runs late, we will delay establishing the FlashCopy relationship until after Production processing completes. We will then run Incremental Backups against the Target disks.
When System or Hardware Test Time is scheduled for Sunday morning, we will interrupt or delay the Full and Offsite Backup process, depending on the schedule for Test Time. We will announce Test Time schedules in advance.
Computing Partners will no longer need to be locked out of the system for extended lengths of time while we prepare disk support for the UCHIBETA LPAR.
Running all the Full and Offsite Backups on Sunday while keeping UCHIBETA down is preferable to delaying availability of UCHIBETA every Sunday and Monday while Full and Offsite backups are being run against the UCHIBETA support disks. If we had kept to our old schedule of Full and Offsite backups while instituting a consistent 4:00 AM FlashCopy relationship window, UCHIBETA could be delayed until 10:30 AM on both Sundays and Mondays.
Another advantage of scheduling all Full and Offsite Backups to run on Sunday is that our onsite and offsite backup files would be congruent for the first time because both sets of backups will be run against the same set of data.
Current FlashCopy Procedure
FlashCopy Relationship: 15 minutes
|01:30||Offsite/Weekly Backups off BETA disks: 6-12 hours|
|04:00||FlashCopy Relationship: 15 minutes||FlashCopy Relationship: 15 minutes||FlashCopy Relationship: 15 minutes||FlashCopy Relationship: 15 minutes||FlashCopy Relationship: 15 minutes||FlashCopy Relationship: 15 minutes|
|04:15||Incremental Backups off BETA disks: 1 hour||Incremental Backups off BETA disks: 1 hour||Incremental Backups off BETA disks: 1 hour||Incremental Backups off BETA disks: 1 hour||Incremental Backups off BETA disks: 1 hour||Incremental Backups off BETA disks: 1 hour|
|08:00||UCHIBETA unavailable all day||UCHIBETA available until 5pm||UCHIBETA available until 5pm||UCHIBETA available until 5pm||UCHIBETA available until 5pm||UCHIBETA available until 5pm||UCHIBETA available until 5pm|