Microsoft recently announced several new updates to its iSCSI-based Azure Elastic SAN, a fully managed and cloud-native storage area network (SAN) offering.
Since the general availability (GA) release of Azure Elastic SAN in early 2024, the company has introduced various new capabilities, such as a public preview of auto scale for capacity, the general availability of snapshot support, and CRC protection.
The company claims that Elastic SAN is the first cloud block storage solution with autoscaling, simplifying management by automatically increasing capacity when storage runs low. This feature allows users to scale on demand through an autoscale policy, reducing the need for excess provisioning and lowering monthly costs. Moreover, users can also set specific increments for growth, ensuring control over expenses while enhancing ease of storage management.
The company describes in the documentation an example:
Here’s an example of how an autoscale policy works. Say you have an elastic SAN that has 100 TiB total storage capacity. This SAN configures volume snapshots, so you want the capacity to scale to automatically accommodate your snapshots. You can set a policy so that whenever the unused capacity is less than or equal to 20 TiB, additional capacity on your SAN increases by 5 TiB, up to a maximum of 150 TiB total storage. So, if you use 80 TiB of space, it automatically provisions an additional 5 TiB, so your SAN now has a total storage capacity of 105 TiB.
With Snapshot support, users can take instant backups of their workloads with Elastic SAN volume snapshots, which can be exported to managed disk snapshots for hardening. Snapshots can be full or incremental, allowing users to restore volumes quickly in case of a disaster.
Microsoft also enabled CRC protection with CRC32C checksum verification to help maintain data integrity. When enabled on the client side, Elastic SAN supports checksum verification at the volume group level, rejecting connections without CRC32C for both header and data digests to prevent errors during data communication or storage.
Azure Elastic SAN is available for all Azure VMware Solution SKUs, including the new AV64 SKUs. This fully managed VMware Certified storage area network allows users to attach iSCSI datastores as VMFS datastores in Azure VMware Solution clusters, expanding storage without increasing local nodes. A key feature is its Zone-Redundant Storage (ZRS), which ensures high availability by storing three copies across different Azure availability zones.
Ray Steele, Technical Architect at a nonprofit Washington School Information Processing Cooperative (WSIPC), said in a recent Microsoft Customer story on Azure Elastic SAN:
We saw that Elastic SAN uses standard iSCSI storage, like our SAN, so no one had to learn a new technology at the operating system level. And the process was scripted, making the connection even more straightforward than we did locally. When I saw the price point and that we could dynamically assign storage, I knew this would fit exactly what we were looking for.
Azure Elastic SAN can also help organizations build cloud applications. Azure Kubernetes Service (AKS) is the new VM for those solutions, while Azure Container Storage simplifies persistent storage management for stateful containers. It integrates seamlessly with AKS and allows persistent volumes (PVs) to be provisioned using Elastic SAN, which shares performance across multiple PVs and overcomes traditional VM limits on volume attachments. Additionally, Azure Container Storage supports ZRS for improved resiliency in workloads.
Lastly, users can optimize costs and resource utilization by using AVS clusters as secondary sites and replicating data to Elastic SAN. It is priced at just $0.06-0.08 per GiB per month in the East US. The pricing page provides more details.
