Skip to Main Content

Breadcrumb

Question and Answer

Connor McDonald

Thanks for the question, Yeong.

Asked: January 22, 2019 - 11:02 am UTC

Last updated: February 24, 2022 - 7:32 am UTC

Version: 12c

Viewed 1000+ times

You Asked

Hello,

I am confused with the requirement needed to setup 2-node (Linux server) RAC with SAN storage, as I am new to this SAN storage.

I see that it is recommended to use ASM as volume manager and file system to RAC instance.
I heard that concurrent i/o access to shared storage from two active nodes is not permitted as it can cause data corruption, and it is the reason why we should use cluster software like VCS or CLVM.

When I see the ASM documents about the storage, I'm not sure if such clusters software should be used with ASM. Is Oracle clusterware, or OCFS automatically contained or ASM? or does ASM internally have concurrent I/O management function like lock distribution? Do I need additional cluster s/w?

and Connor said...

For a RAC cluster, you *must* use the Oracle Clusterware to managed the nodes.

Part of the clusterware is ASM, but it is not *mandatory* that you use ASM. If you choose not to use ASM however, than the shared file system architecture you use must be certified by Oracle as being ok for RAC.

The most common usage for shared storage for RAC is:

- ASM
- NFS

https://docs.oracle.com/en/database/oracle/oracle-database/12.2/cwsol/about-direct-nfs-client-mounts-to-nfs-storage-devices.html#GUID-31591084-74BD-4B66-8C5B-68BF0FEE8750


Rating

  (1 rating)

Is this answer out of date? If it is, please let us know via a Comment

Comments

Pratyush, February 23, 2022 - 3:20 pm UTC

Can we install and configure Oracle ASM 19c, without configuring Oracle clusterware ??
Connor McDonald
February 24, 2022 - 7:32 am UTC

You need to install what we call the "grid infrastructure" which contains ASM as a component.

When you run the grid installer, you'll tell it that you're not using a cluster but just a standalone machine for ASM

ORACLE_ASM_INSTALL

more

Connor and Chris don't just spend all day on AskTOM. You can also catch regular content via Connor's blog and Chris's blog. Or if video is more your thing, check out Connor's latest video and Chris's latest video from their Youtube channels. And of course, keep up to date with AskTOM via the official twitter account.