Low-Latency Block Storage Multi-AZ Migration

SAA-C03 By islever Editorial Last updated

Design highly available and/or fault-tolerant architectures.

Short answer

C Use Amazon FSx for NetApp ONTAP with iSCSI for managed multi-AZ block storage access.

Question

A company currently runs an on-premises stock trading application by using Microsoft Windows Server. The company wants to migrate the application to the AWS Cloud. The company needs to design a highly available solution that provides low-latency access to block storage across multiple Availability Zones. Which solution will meet these requirements with the LEAST implementation effort?
  1. Configure a Windows Server cluster that spans two Availability Zones on Amazon EC2 instances. Install the application on both cluster nodes. Use Amazon FSx for Windows File Server as shared storage between the two cluster nodes.
  2. Configure a Windows Server cluster that spans two Availability Zones on Amazon EC2 instances. Install the application on both cluster nodes. Use Amazon Elastic Block Store (Amazon EBS) General Purpose SSD (gp3) volumes as storage attached to the EC2 instances. Set up application-level replication to sync data from one EBS volume in one Availability Zone to another EBS volume in the second Availability Zone.
  3. Deploy the application on Amazon EC2 instances in two Availability Zones. Configure one EC2 instance as active and the second EC2 instance in standby mode. Use an Amazon FSx for NetApp ONTAP Multi-AZ file system to access the data by using Internet Small Computer Systems Interface (iSCSI) protocol. Correct Answer
  4. Deploy the application on Amazon EC2 instances in two Availability Zones. Configure one EC2 instance as active and the second EC2 instance in standby mode. Use Amazon Elastic Block Store (Amazon EBS) Provisioned IOPS SSD (io2) volumes as storage attached to the EC2 instances. Set up Amazon EBS level replication to sync data from one io2 volume in one Availability Zone to another io2 volume in the second Availability Zone.

Key Takeaways

The core trap is confusing file storage (FSx for Windows) with block storage requirements; only FSx for NetApp ONTAP provides managed multi-AZ block storage via iSCSI without complex custom replication setup.

This question tests designing a highly available, low-latency block storage solution for a Windows Server migration with minimal implementation effort. The correct answer identifies Amazon FSx for NetApp ONTAP as the managed service that natively supports iSCSI block access across Availability Zones.

Common mistake: Many learners choose A because FSx for Windows File Server is optimized for Windows workloads, but it provides SMB/NFS file shares, not the required block-level iSCSI access needed for stock trading applications.

Expert Analysis

Why the Answer Is Correct

Option C is the correct choice because Amazon FSx for NetApp ONTAP is a fully managed file system that supports the iSCSI protocol, providing low-latency block storage access to EC2 instances. It natively offers Multi-AZ deployment capabilities, ensuring high availability across Availability Zones without requiring manual configuration of replication or clustering logic. This aligns perfectly with the 'LEAST implementation effort' requirement by offloading storage management to AWS.

Why the Other Options Are Wrong

Option A uses FSx for Windows File Server, which provides SMB/CIFS file shares, not block storage, making it unsuitable for applications requiring block-level access. Option B and D rely on EBS volumes, which are single-AZ resources; achieving multi-AZ availability requires setting up application-level or volume-level replication, which contradicts the 'least implementation effort' constraint and adds significant operational overhead compared to a managed multi-AZ service.

Community Comment Notes

Community consensus strongly favors C due to the explicit mention of 'block storage'. As LeonSauveterre noted, FSx for Windows is file-based, while FSx for NetApp ONTAP supports iSCSI for block access. Some users like Bwhizzy argue for A based on Windows compatibility, but this overlooks the specific storage protocol requirement. Martinadurcakova1 correctly points out that EBS replication in D is complex and high-effort.

Exam Strategy

Always distinguish between file storage protocols (SMB, NFS) and block storage protocols (iSCSI, NVMe). When a question specifies 'block storage' and 'low latency', look for EBS or FSx for NetApp ONTAP with iSCSI support, avoiding FSx for Windows unless file sharing is explicitly requested.

Frequently Asked Questions

Why not use FSx for Windows File Server for Windows workloads?

FSx for Windows provides SMB/NFS file shares, not block storage. Stock trading apps often require block-level access for performance.

Is EBS Multi-AZ replication the least effort?

No. EBS volumes are single-AZ. Replicating them across AZs requires manual setup or third-party tools, increasing implementation effort significantly.

More SAA-C03 FAQ →

Community Votes

C
63%
A
38%

63% of anonymous learners picked answer C. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 16 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 16

  1. martinadurcakova1 👍 4
    Using Amazon FSx for Windows File Server would not be the best solution, as the company requires block storage, not file storage. D. Deploying the application on EC2 instances and using Amazon EBS Provisioned IOPS SSD (io2) volumes with EBS-level replication is the solution with the least implementation effort for the following reasons: EBS volumes provide the required block storage for the application. Using EBS-level replication to sync data between Availability Zones is a built-in feature, requiring less implementation effort compared to setting up custom replication mechanisms. Provisioned IOPS SSD (io2) volumes ensure the low-latency access to the block storage required by the application. By using Amazon EBS Provisioned IOPS SSD (io2) volumes with EBS-level replication, the company can meet the requirements for high availability and low-latency access to block storage with the least implementation effort.
  2. LeonSauveterre 👍 4 Answered C
    Keep in mind: WE NEED LOW LATENCY BLOCK STORAGE. A - FSx for Windows File Server is not designed for block storage. It is optimized for shared file storage. B - God this requires high implementation effort. C - FSx for NetApp ONTAP supports block storage (via iSCSI) and provides Multi-AZ fault tolerance out of the box. D - EBS io2 volumes with replication across AZs are hard and complex to configure and manage. Even if you think this is acceptable, still it's definitely much harder than option C.
  3. Anyio 👍 3 Answered C
    The correct answer is C. Explanation: Option C: Correct. Amazon FSx for NetApp ONTAP provides a managed file storage solution that supports iSCSI protocol for block storage access, enabling low-latency, highly available access to shared storage across multiple Availability Zones. This solution requires less implementation effort because Amazon FSx manages the complex underlying multi-AZ configuration and data replication automatically. Option A: Incorrect. While Amazon FSx for Windows File Server provides a managed shared storage solution, it is primarily used for SMB-based file shares rather than block storage needs like those typically demanded by stock trading applications. Also, it might introduce additional latency for block-level access.
  4. rpmaws 👍 3 Answered C
    due to this line in question "low-latency access to block storage" C looks appropriate.
  5. spoved 👍 3 Answered D
    block storage -> B or D io1, io2 support EBS Multi-Attach -> D
Show 11 more comments
  1. Bwhizzy 👍 2 Answered A
    Answer is A. Amazon FSx for Windows File Server provides fully managed shared storage designed for Windows workloads. It offers seamless integration with Windows applications and supports Windows Server Failover Clustering (WSFC), making it the ideal choice for clustering applications. High availability is provided as the cluster spans multiple Availability Zones, ensuring that the application continues to function in case of an AZ failure. Low-latency access to shared block storage is achievable with FSx, and it reduces the complexity compared to setting up replication between multiple Amazon EBS volumes. Least implementation effort: You don't need to manage block-level replication or create complex replication setups between AZs, as FSx for Windows File Server handles this automatically. It simplifies storage management and offers native Windows support.
  2. HappyG 👍 2 Answered C
    Key word in the question is block storage which eliminates A as a possibility. FSx for NetApp ONTAP provides low-latency block storage, multi-AZ high availability, and requires the least implementation effort because it is a fully managed service with built-in replication and failover capabilities. This makes it the most suitable and cost-effective option for the company's needs.
  3. toyaji 👍 2 Answered A
    A - Windows cluster across two availability zones satisfies highly available condition and FSx satisfies storage access from multiple ec2 especially for Windows server. B - "Set up application-level replication to sync data" not for LEAST effort condition C, D - "in standby mode" need to be activated manually so its not highly available
  4. EllenLiu 👍 2 Answered C
    block storage => FSx for NetApp ONTAP not only provides iSCSI(for block) support, but also offers comprehensive protocol support including SMB and NFS.
  5. JoeTromundo 👍 2 Answered A
    For those who are choosing option other than A: what part of "with the LEAST implementation effort" do you not understand?
  6. ckhemani 👍 1 Answered A
    Answer A. Although they are looking for Block storage which is EBS but EBS can't be shared across two availabilty zones . Multi-Attach feature: While you can use the "Multi-Attach" feature to attach a single EBS volume to multiple instances within the same Availability Zone, this does not allow sharing across different Availability Zones. Configuring NETAPP is not least operational.
  7. rosanna 👍 1 Answered D
    block means EBS, and I've searched but I don't see Fsx supporting shared block storage, not that I know of, and thinking about if it did exist, I would cost more than a replica- both operationally and money wise. And mostly we don't need complex methods so I'd go for D
  8. ARV14 👍 1 Answered C
    Fsx windows file server does not provide block storage, also Ontap provides very low latency and provides various compatible storage including block
  9. ashishs174 👍 1
    Answer is B EFS is not Block Storage, EBS is.( Thus, A and C are out)
  10. elmyth 👍 2 Answered B
    Block storage
  11. dhewa 👍 2 Answered A
    Windows = FSX

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