Snapshot backup on ODA - VM Snapshot or ACFS Snapshot - Which is faster and easier

[Viswanath Jayakumar (Viswa)]

Dear Erman,

Our Client wishes to create daily snapshot from ODA box at either VM Level or Database (ACFS Snapshot) level.

My Query is:
1. If creating VM level snapshot backup, does this VM snapshot contain all the O/s and also DB (database) snapshot and how fast is it to take the snapshot on VM level and how fast it can be restored if the DB and Application sizes is nearly 1TB.

2. How useful is ACFS snapshot and can this ACFS snapshot be taken incremental depending on the CDC or Archive logs etc?

Thanks & Regards
Viswa

[ErmanArslansOracleBlog]

Did you check this note-> ODAVP (Oracle Database Appliance Virtualized Platform): Guest VM replication (Doc ID 1993072.1)

In this note, you will find the following;

VM Guest replication using RSync command
VM Guest filesystem replication
ACFS Replication restrictions
ACFS Replication consideration
VM Guest copy leveraging on snapshot feature

After reading this document, we can discuss further..

[Viswanath Jayakumar (Viswa)]

The document ID provided earlier is good, but I needed more details as please do go thru the below query placed yesterday.

My Query is:
1. If creating VM level snapshot backup, does this VM snapshot contain all the O/s and also DB (database) snapshot and how fast is it to take the snapshot on VM level and how fast it can be restored if the DB and Application sizes is nearly 1TB.

2. How useful is ACFS snapshot and can this ACFS snapshot be taken incremental depending on the CDC or Archive logs etc?

I need to know which type of snapshot is better. VM snapshot or ACFS snapshot. They need for database files, application files and System files for quick restore.

[ErmanArslansOracleBlog]

Ok. Let's try to answer your questions one by one.

*ACFS based snapshot replication is based on rlogs. (no archivelogs or cdc) It is rlogs..
ACFS replication is always asynchronous (rlogs are transported once the current set contains a sufficient amount of changes)

*ACFS based replication is a little tricky. It is not supported unless you have replicated ACFS volume exported as HA-NFS.

*VM level snapshot contains your vdisks.. So it contains pretty much everything. (I mean -> VM Guest copy leveraging on snapshot feature).. This should not take a lot of time. It must be quick.. But you need to test it. It is based on snapshot technique.. So the size of the data shouldn't have a big effect on the duration.
High level steps for this is documented->

- Stop the local application guest VM
- Take a guest VM snapshot "oakcli clone {vm <vm_name> | vdisk <vdisk_name>} -snap"
- Start the local application guest VM
- Copy the local guest VM virtual disks from the snapshot above to the remote site

[ErmanArslansOracleBlog]

Also check this doc->ODAVP: HowTo backup/restore your VM Guest (Doc ID 1633166.1)

You may build a combined method and create a solution for your case on your own by following the 2 documents that I shared with you..