Block storage
Amazon EBS Multi-Attach vs Azure shared disks
EBS Multi-Attach maps to Azure shared disks.
Both expose one volume to several VMs, and both need a cluster manager or cluster-aware file system to coordinate writes.
Side-by-side comparison
| Aspect | Amazon Web Services | Microsoft Azure |
|---|---|---|
| Service | Amazon EBS Multi-Attach | Azure shared disks |
| Lifecycle | Generally available | Generally available |
| What it is | Attach one io1 or io2 volume to up to 16 Nitro instances in the same AZ. Applications must coordinate writes (a cluster-aware file system or application). Windows supports io2 only. | Attach one Ultra Disk, Premium SSD v2, Premium SSD, or Standard SSD to multiple VMs at once, coordinated through SCSI persistent reservations or NVMe reservations by a cluster manager such as WSFC or Pacemaker. |
| Pricing model | No extra charge beyond io1 or io2 volume pricing. | Normal managed disk pricing. Check the pricing page for shared-disk specifics. |
| Docs | Amazon EBS Multi-Attach docs | Azure shared disks docs |
| Pricing page | Amazon EBS Multi-Attach pricing | Azure shared disks pricing |
| Exams | SAA-C03 SOA-C03 | AZ-104 AZ-305 |
Key differences
- Disk types. Multi-Attach supports only io1 and io2 (io2 only on Windows), on up to 16 Nitro instances in one AZ. Azure shared disks work with Ultra Disk, Premium SSD v2, Premium SSD, and Standard SSD, with a per-disk limit on attached VMs (maxShares).
- Coordination. Azure documents SCSI persistent reservations and NVMe reservations, used by WSFC and Pacemaker. On AWS, the application or a cluster-aware file system must manage write ordering.
- Zones. ZRS shared disks can be attached to VMs in different zones. EBS Multi-Attach is single-AZ.
Pricing summary
Pricing models only. No prices are quoted because they change by region and over time.
- AWS
- No extra charge beyond io1 or io2 volume pricing. Amazon EBS Multi-Attach pricing →
- Azure
- Normal managed disk pricing. Check the pricing page for shared-disk specifics. Azure shared disks pricing →
Certification exam mapping
| Exam | Provider | Level | Status |
|---|---|---|---|
| AWS Certified Solutions Architect – Associate SAA-C03 | AWS | Associate | current Italian version retires after Dec 31, 2026. |
| AWS Certified CloudOps Engineer – Associate SOA-C03 | AWS | Associate | current Replaces AWS Certified SysOps Administrator – Associate (SOA-C02), whose last exam day was Sep 29, 2025. Simplified Chinese and Korean versions retire after Nov 19, 2026. |
| Microsoft Certified – Azure Administrator Associate AZ-104 | Azure | Associate | current |
| Microsoft Certified – Azure Solutions Architect Expert AZ-305 | Azure | Expert | current English version updated Apr 17, 2026. |
Relevance is based on each exam's published scope, not a line-by-line objective match. Check the official study guide.
FAQ
What is the Azure equivalent of Amazon EBS Multi-Attach?
EBS Multi-Attach maps to Azure shared disks. Both expose one volume to several VMs, and both need a cluster manager or cluster-aware file system to coordinate writes.
How does pricing compare between Amazon EBS Multi-Attach and Azure shared disks?
AWS: No extra charge beyond io1 or io2 volume pricing. Azure: Normal managed disk pricing. Check the pricing page for shared-disk specifics. Check the official pricing pages for current rates.
Which certification exams cover this topic?
AWS Certified Solutions Architect – Associate (SAA-C03); AWS Certified CloudOps Engineer – Associate (SOA-C03); Microsoft Certified – Azure Administrator Associate (AZ-104); Microsoft Certified – Azure Solutions Architect Expert (AZ-305).