The Oracle’s documentation is pretty clear regarding restrictions when using Flex Asm with databases:

Table 4-4 Oracle ASM features enabled by disk group compatibility attribute settings

Oracle ASM flex and extended disk groups >= 12.2 >= 12.2 n/a


Well, we are going to explain how to avoid this restriction.

The point is… to have it running on Acfs. 🙂

The database:


The diskgroups:


The cluster:


We launch more than 300.000TPMs with the tool swingbench on the machine:

We kill the Asm on the machine:


The instance’s alert on Acfs doesn’t realize, it continues working…

The cluster’s alert the only thing it shows:


But the services and databases depending on Asm are running without stop:


Even if we stop with abort and force the Asm on the node, everything is ok:


Now, you have another reason to migrate to Acfs 😉

You don’t forget another main reason which is the “snapshot” of our databases for backups and prepare test environments in minutes!!.

We recommend the use of the tool gDBClone.


Adding value with Arumel!!

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