HP StorageWorks XP24000 for FlashCopy Mirroring Software User's Guide (T5240-96001, June 2007)

Tabl e 45 Differences of the M axim um Number of Relationships Bet ween I BM
FlashCopy and Version 2
Compared Item IBM FlashCopy
Version 2
Number of multiple
relationships
Up to 12 relationships can be created
per extent (the smallest unit: track).
Up to 16 relationships can be created
per extent (the smallest unit: track).
Maximum number
of
pairs that can be
created per volume
951 relationships (for 3390-3)
2,719 relationships (for 3390-9 when
the
number of available cylinders is
10,017)
7,615 relationships (for 3390-L when
the
number of available cylinders is
28,356)
8,839 relationships (for 3390-L when
the
number of available cylinders is
32,760)
1,000 relationships (for all volume
types)
Comparison
of
Copy ing Pr ocess
The followi
ng
table shows the differences between the copying process for IBM FlashCopy and HP’s
Version 2.
Table 46 Differences of Copying Process Bet ween I BM FlashCopy an d Version 2
Compared Item IBM FlashCopy
Version 2
Read access to an
area not specified as
the
copy range in the
copy target during the
background copying
process in NOCOPY
mode
The data on the tracks subject to the
read operation is not copied from the
copy source to the copy target.
Sometimes the data on the tracks
subject to the read operation is copied
from the copy source to the copy
target, and other times the data is not
copied to the target.
Status of the pairs when
on-demand
copy is
processed
Relationships are withdrawn
automatically when all the copy
operations processed by an
On-demand copy are completed.
Relationships are maintained even
when all the copy operations
processed by an On-demand copy are
completed.
Establishing
relationships by using
the
TSO command
when you specify a
copy target volume
of PPRC as a source
volume
Supported.
The ACTION (FREEZE) option can be
used.
Not supported.
The command will be rejected.
Comparison of Relationship Releasing Process
The following table shows the differences between the relationship releasing p rocess for IBM FlashCopy
and HP’s Version 2.
106
Feature Comparison with the IBM Product