Disk space used by FlashCopy images

FlashCopy® images consume space on the same volumes as the original fileset. Because FlashCopy uses a space-efficient method to make the image, the amount of space that is used by FlashCopy images is not possible to predict. If all blocks in the fileset are changed, the image takes up the same amount of space currently occupied by the non-FlashCopy objects within the fileset. If nothing in the fileset changes, the FlashCopy images takes up virtually no space (just pointers to the real fileset data). It is not possible to determine how much space is being occupied by a particular FlashCopy image at any particular time.

Therefore, when you plan your space requirements, include space for FlashCopy images. The amount of space you need to plan for flashcopy images correlates to the amount of changes you make to files with flashcopy images. Carefully monitor the user-storage-pool space threshold. Be aware that the space used by FlashCopy images count toward the fileset's quota.

Parent topic: FlashCopy images

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