3PAR InForm® OS 2.3.1 Concepts Guide (320-200112 Rev B, February 2010)
10.6
Physical Copies
3PAR InForm OS Concepts Guide InForm OS Version 2.3.1
◆ for a TPVV with read-only snapshots, or when that TPVV is a physical copy or used for
Remote Copy, n=2.
For example, if a 1 TB TPVV with read-only snapshots has a maximum write rate of 1 GB per
day and you would like 30 days warning prior to that TPVV reaching the allocation limit,
use the following calculation for the allocation warning percentage:
10.3 Physical Copies
A physical copy is a point-in-time copy that duplicates all the data from one original base
volume to another volume called the destination volume. This is done so that the data on the
destination volume can be used if the original base volume becomes unavailable. Any changes
to either volume causes them to lose synchronization with each other, which is corrected by
resynchronizing the two volumes as described in the InForm OS CLI Administrator’s Manual
and the InForm OS Management Console Online Help. No special license is required to create a
physical copy of a volume.
Physical copies can be created and managed in groups to reduce the number of management
tasks. You can create a consistent group physical copies form a list of virtual volumes, and
group physical copies into autonomic groups that are managed as one physical copy.
A physical copy can only be made from a volume with enough free space to accommodate
writes to that volume during the physical copy operation. In addition, the destination volume
must meet the following conditions:
■ It must have snapshot space associated with.
■ It must have at least as much user space as the volume being copied.
■ It must not be exported to a host.
2 1 GB per day
1024 GB
Allocation warning = 1 —
••
30 days
=
94 %
•
100
percentage
NOTE: If the base and destination volume are both Thinly-Provisioned Virtual
Volumes (TPVVs), only the space that is actually used is copied. See Chapter 2,
Overview for additional information on TPVVs.