ASA stands for All-flash SAN Array. ASA based on low-end & high-end AFF systems that are using ONTAP.
ONTAP architecture in ASA systems remains the same, with no changes. The only change is in the access to the storage over SAN protocols.
In (non-ASA) Unified ONTAP systems SAN protocols like FC and iSCSI are using ALUA which stands for Asymmetrical Logical Unit Access so, this type of connection called active/active but uses ”active optimized” and ”active non-optimized” paths. NVMe ANA works similar to ALUA for SCSI-Based protocols. Both with ANA & ALUA in case of one storage controller failure, the host waits for a timeout, before the host switches to the active non-optimized path. Which works perfectly fine. See more in the section ”Share-nothing architecture”, and “Network access” in a series of articles ”How ONTAP Cluster works”.
But there are some customers who were:
- Used to the idea of symmetric active/active connectivity
- Looking for a product that will provide fewer notifications to the host at the event of a path loss
NetApp listened to its customers, evaluated both requests and provided ASA products that give the solution they have been looking for.
Video with Skip Shapiro about ASA: