12 Replies Latest reply: Jan 19, 2015 8:12 AM by forshr RSS

Comparing different types of Image Access modes


There are several options on how to use Image Access modes within RecoverPoint and its important to understand how each affect different use cases so they can meet your requirements in terms of usage. Each one has the ability of presenting a point in time image of data to a host in either a CDP or CRR configuration. Each type also has its benefits depending on the use case


There are 4 types of Image Access Modes:

1. Logged Access

2. Virtual Access

3. Virtual Access with roll

4. Direct Access


1. Logged Access  - This mode gives you the abilty to offer a physical representation of a point in time that is represented in the RecoverPoint journal.  This requires the image in the journal to be copied to the phsyical replica which can take some time, but will higher performance. In this version, all new writes are written to the replica volume and undo information is stored in the image access log, which is located within the journal. This version would be perfect for typical recoveries, testing, backup solutions where time to recovery is not as important as performance.


2. Virtual Access - This mode of recovery offers intant access to a point in time copy. This is a great fit for performing a recovery of a small data set or light testing where performance is not important, but RTO is more important. In this mode, RecoverPoint will present the volume in a virtualized manner using  both the journal and replica volume. In virtual access, all new writes are written to the image access log, which resides in the journal.


3. Virtual Access with Roll - This mode offers virtual access in the same manner as listed above except there is an option to copy the journal image that was chosed to recover, to be copied to the replica in the background. This version is a good fit for recoveries that are relatively far back in time, but there is a requirement to have immediate access. RecoverPoint image will initially have the same performance characteristics as virtual acess, but ultimately have the same features as Logged Access once the roll(copy) of the image to the replica volume is complete in the background.


4. Direct Access - This mode is slightly different than the rest and can be used only after one of the other 3 have been enabled on a recovery first. Direct access offers the option for long term testing since it does not rely on the journal at all for UNDO information for the image access log. In this mode, the journal is not kept and a full sweep is done once direct access mode is complete. This is an option for long term tests where the journal may not have enough space for long term image access mode.