If you want to create multiple copies of the same source volume
or take advantage of other advanced FlashCopy® enhancements, consider obtaining a license
for the ESS FlashCopy V2
feature. The following list describes some of the requirements for
using FlashCopy V2:
- The source and target FlashCopy volumes
must reside in the same ESS, but the target volume can reside in a
different LSS from the source volumes.
- A target track can reside on any eligible device in the same LSS
as its associated source, including the same volume. When both source
and target tracks are on the same volume, the single FlashCopy relationship restriction
for a target track prevents this type of source and track relationship
from using the same tracks.
- The target device must have the number of source tracks specified
in the FlashCopy request,
but not necessarily as many tracks as the source device.
- FlashCopy operations
accommodate the relocation of tracks as long as the following specifications
are met:
- The number of specified target tracks must equal the number of
specified source tracks on a given FlashCopy establish
request
- The track format and geometry of the source and target volumes
must be the same. (Track format and geometry refer to 3380TCM versus
3390 format and number of tracks per cylinder.)
- Each device is allowed up to a maximum number of FlashCopy relationships. Use
the FCQUERY request to determine this maximum number.
- A source device track can be in a FlashCopy relationship with up to 12 different target
tracks.
- A specified target track cannot also be a source track, and a
target track cannot be in more than one FlashCopy relationship.
Due to TSO command length restrictions, you can specify 1–32
extent sets using the FlashCopy V2
XTNTLST keyword with the FlashCopy FCESTABL
command. When using the ANTRQST API services
for FlashCopy, including
invoking them through ANTTREXX, you can specify 1 to 110 extent sets.