3PAR InForm® OS 2.2.4 Concepts Guide (320-200085 Rev B, March 2009)

8.10
Virtual Volume Types and Variations
3PAR InForm OS Concepts Guide InForm OS Version 2.2.4
Figure 8-4. Snapshot tree
The relationships between the virtual copies derived from a base volume can be represented as
a tree, with the base volume as the starting point.
In this example, each new virtual copy of the original has its name incremented by 1; for
example: S0, S1, S2. Note that each new copy is inserted closer to the base of the tree
(basevv).
Each copy of a copy has an additional level added to its name: in this example, the first copy of
S1 is S1_0, and a copy of S1_0 is S1_0_0. (Unlike the automatic snapshots created for
physical copies, these snapshots are not assigned names by the system.)
baseVV
(RW)
S0
(RO)
S1
(RO)
S2
(RO)
Parent
Parent
S1_0
(RW)
Parent
Copy of
S1_0_1
(RO)
Parent
Copy of
S1_0_0
(RO)
Copy of
Copy of
Parent
Copy of
Parent
Copy of
S0 is the first virtual copy made of baseVV; S2 is the
most recent virtual copy. Each copy tracks changes
made to baseVV from its own creation date until the
next snapshot is made.
S1_0 can be created at any time after S1 is created.
NOTE: The naming convention used in the example above is recommended, but it
is not enforced by the system. You name each virtual volume and virtual copy at
the time of creation.