ACFS Snapshot Requirements for ADVM Compatibility
Short answer
A The disk group compatibility attribute for ADVM must be set to 12.1 or higher.
Question
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Key Takeaways
The exam tests knowledge of ACFS snapshot constraints, specifically the trap that students might confuse read-only requirements with version compatibility settings.
This question tests the prerequisites for creating ACFS snapshots in Oracle ASM. It establishes that the ADVM compatibility attribute must be set to 12.1 or higher for successful snapshot creation.
Common mistake: Candidates often incorrectly select B (read-only) because traditional backups are read-only, but ACFS snapshots can be created from read/write file systems if compatibility is met.
Expert Analysis
Why the Answer Is Correct
The correct answer is A because Oracle documentation explicitly states that creating a snapshot from an existing snapshot is not permitted if any snapshots in the file system were created with an ADVM compatibility level lower than 12.1. This ensures that the underlying volume management features support the snapshot functionality.
Why the Other Options Are Wrong
Options B and D discuss the read-only/read-write state of the parent snapshot. ACFS snapshots can be created from both read-only and read/write file systems, so neither is a strict requirement for success. Option C is incorrect because redundancy levels (high, normal, external) do not impact the ability to create snapshots; they only affect data protection.
Community Comment Notes
As Test_1 noted, "Creation from an existing snapshot is not permitted if there are: Any snapshots present in the file system that were created with the ADVM compatibility set to less than 12.1." Another user confirmed that "the parent snap can be RW," reinforcing that the compatibility setting is the critical constraint, not the state of the filesystem.
Official Reference
https://docs.oracle.com/en/database/oracle/oracle-database/21/acfsg/acfs-commands-snapshots.html
This link opens the official vendor documentation in a new tab.
Exam Strategy
Focus on specific version numbers and compatibility attributes in Oracle exams. When asked about prerequisites for advanced features like ACFS snapshots, always check for minimum version requirements first before considering state-based conditions.
Frequently Asked Questions
Can ACFS snapshots be created from read/write file systems?
Why is high redundancy not required for ACFS snapshots?
Community Votes
100% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.
Discussion 3 contributions
Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.
From public community threads 3
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krwi1 👍 2 Answered AB - wrong - the parent snap can be RW, but it has to be created on compatible >=12.1 Creation from an existing snapshot is not permitted if there are: Any snapshots present in the file system that were created with the ADVM compatibility set to less than 12.1 https://docs.oracle.com/en/database/oracle/oracle-database/21/acfsg/acfs-commands-snapshots.html#GUID-A1E4A4B5-CD16-4ADC-817D-4CD7D2DA12DF
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lcoleandro 👍 2 Answered AA. Correct: ADVM compatibility must be 12.1 or higher for the parent snapshot feature. B. Incorrect: The parent snapshot can be read/write; it doesn't have to be read-only. C. Incorrect: High redundancy is not required for creating snapshots. D. Incorrect: The parent snapshot can be either read/write or read-only.
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Test_1 👍 2Correct answer is A. Creation from an existing snapshot is not permitted if there are: Any snapshots present in the file system that were created with the ADVM compatibility set to less than 12.1
Reader comments & corrections
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