Both terms are industry accepted terminology. So Tiers 1, 2 and 3 may refer
to the performance of online storage or it may be used to refer to the locations
The site locations are;
We can do disk to disk replication (media is mountable and data usable)
These are both online
We could also do disk to tape
This is online and nearline
We can use disk to disk replication
This could still be online
We could do disk to tape
In which case this could be offline
So we have different mechanisms we can use
When we are trying to decide, firstly we need to look at;
How valuable the information is
What kind of information is it
Where’s the best place to store it
Typically we want to put it on the storage at the lowest cost that meets
the requirement. We don’t want to keep all of our data on Tier 1 storage
just because we have to keep something for 6 years because we are not
allowed to delete it. It should be moved to lower cost storage that still
meets the performance requirement.
The value of data will change over time.
Backup is about recovering production data.
The definition of archive is about storing infrequently used data for long
periods of time, typically on lower cost media. There are often set
periods that this data has to be kept.