Release Notes

11 Dell PS Series Snapshots and Clones: Best Practices and Sizing Guidelines | BP1027
3.3 Differences between PS Series snapshots and clone volumes
Differentiating factors between snapshots and clones:
Snapshot
Clone Volume
Definition
Point-in-time copy of a volume
Full copy of a volume
Location
Base volume and snapshots always
reside in the same storage pool
Once a clone volume is created, it can be
moved to any pool that contains adequate
free space
Functionality
When a snapshot is created, it is
instantly available, and no data is
moved or copied
When a clone volume is created, it is
instantly available to the user. All regular
volume operations can be performed on
the clone volume once the cloning
operation is complete.
Deletion
Deleting a snapshot’s parent volume
deletes all associated snapshots for
that volume
Deleting the source volume where a clone
volume was created does not delete a
clone volume.
Association with the
source volume
A snapshot does not initially
consume any space but instead is a
set of pointers to the data in the
base volume. As data is modified on
the base volume, disk space is
allocated from the snapshot reserve
to store the modified data.
A clone volume creates a full copy of the
original volume, consuming 100% of the
original volume size from free space in the
pool where the original volume resides. A
clone volume uses unique, non-shared
blocks (or pages) of data.
Use Cases
• Short-term local data protection:
Rapid restores of data from
multiple recovery points in case of
a file corruption or accidental
deletion.
• Backup and Recovery: Offload
backup operations to another
server.
• Additional copies of data: Provide
other servers secure access to a
copy of production data
• Test and Development: Independent full
copy of the source volume can be used
for testing and development purposes.
• Data Reporting and Data warehousing:
Clones can be used for running end of
the month/quarter/year reporting.
• Compliance and Legal hold: A read only
copy of a clone can be used to store
data history for compliance and legal
hold purposes.