• Snapshots are a relatively “impact-free” replication technique
• Only original data that has been changed is copied • Snapshot process runs independently of application I/O
Pros
Minimal impact on application performance
Minimal use of SAN bandwidth
Point-in-time copy protects against corrupted data
Cons
Snapshot data set is never 100% up to date
No protection against disk failure
Relies on Primary storage still being available
Only original data that has been changed is copied, it relies on the primary volume, so minimal impact on application performance because this is all happening inside the subsystem.
Minimal use of SAN bandwidth. It’s in-system replication and it can protect us against corrupt data because it’s a point in time copy. As long as we took our snapshot before the corruption occurred, we can roll back to before the corruption occurred.
The downside is that it is a snapshot. It’s never 100% up to date. It’s a point in time copy and there’s no protection against disk and primary volume failure because this relies on accessing the original logical unit for the original data.