Famous words from William Shakespeare’s play Hamlet. Act III, Scene I.
This is true even in the Virtualization world for Oracle Business Critical Applications where one wonders which way to go when it comes to provisioning shared disks for Oracle RAC disks, Raw Device Mappings (RDM) or VMDK ?
Much has been written and discussed about RDM and VMDK and this post will focus on the Oracle RAC shared disks use case.
Some common questions I get talking to our customer who are embarking on the virtualization journey for Oracle on vSphere are
- What is the recommended approach when it comes to provisioning storage for Oracle RAC or Oracle Single instance? Is it VMDK or RDM?
- What is the use case for each approach?
- How do I provision shared RDM (s) in Physical or Virtual Compatibility mode for an Oracle RAC environment?
- If I use shared RDM (s) (Physical or Virtual) will I be able to vMotion my RAC VM ’s without any cluster node eviction?