How does auto-extend work on ONTAP volumes?

• A. It creates automatic backups to a secondary data center.
• B. It expands the volume automatically when space usage nears a threshold and there is free space on the underlying aggregate.
• C. It converts the volume to all-flash.
• D. It deletes old data to reclaim space.

Answer: (B)

Auto-extend is a feature that keeps a volume growing automatically as it begins to run out of space. When the volume’s used space hits a configured threshold, ONTAP checks whether the backing aggregate has free space. If there is free space, the volume is enlarged by a defined increment so applications can continue writing without manual resizing. This relies on two settings: the space usage threshold and the extension increment, and it only works if there is available capacity in the aggregate. If the aggregate has no free space, auto-extend won’t occur and you could hit an out-of-space condition. This behavior is about dynamically growing storage, not about backing up data, converting the volume to all-flash, or deleting old data to reclaim space.