Regional ESSDs replicate data synchronously across multiple availability zones, each with independent data centers, racks, and power supplies, to maintain uninterrupted service during zone-level failures.
Overview
Advantages
Regional ESSDs offer the following advantages over other cloud disk types:
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Zero Recovery Point Objective (RPO): Synchronous writes across multiple availability zones handle physical data replication automatically, eliminating the complex replication logic required by on-premises storage solutions.
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Enhanced Business Continuity at a lower cost: Achieve application-level disaster recovery without additional ECS instances, bandwidth, or compute resources typically required in manual failover setups.
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Regional ESSDs retain the same enterprise-grade features as standard ESSDs.
Synchronous replication across availability zones increases average write latency slightly compared to a PL1 ESSD. Regional ESSDs are ideal for applications that require zero data loss from zone failures and can tolerate this minor latency increase.
Use cases
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High-availability databases across multiple Availability Zones
Traditional database deployments use primary/secondary replication for high availability and cross-zone disaster recovery, but this introduces replication delays and potential data inconsistency. With a Regional ESSD, deploy a single compute node in Availability Zone A and attach the Regional ESSD. No secondary compute node in Availability Zone B or primary/secondary replication is needed — the disk's physical replication handles cross-zone data redundancy automatically. If a failure occurs, launch a new compute node in Availability Zone B and attach the disk to restore service. This reduces storage costs by up to 25% and compute costs by up to 50%.
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Deploy containers across Availability Zones
Container deployments often struggle with elasticity and disaster recovery for stateful applications across multiple availability zones. Regional ESSDs upgrade single-zone stateful applications to multi-zone disaster-resilient ones with no code changes. If a compute node or entire availability zone fails, or zone resources become insufficient, migrate the container to another availability zone without data synchronization or data validation.
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Build or deploy Software as a Service (SaaS) applications
Building or deploying a SaaS application typically requires two parallel ECS clusters in different availability zones for high availability. Regional ESSDs provide a low-cost cross-zone alternative.
Billing
Regional ESSDs are billed by capacity and support both pay-as-you-go and subscription models. See Block storage devices for billing rules.
Limitations
Supported regions
Regional ESSDs are available in the following regions: China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Shenzhen), China (Ulanqab), China (Hong Kong), Singapore, Malaysia (Kuala Lumpur), and Indonesia (Jakarta).
Supported instance types
See Instance family overview for instance families that support Regional ESSDs.
Feature limitations
|
Feature type |
Feature |
Supported by Regional ESSDs |
|
Basic features of cloud disks |
Create, view, modify, and release disks |
Yes |
|
Data encryption |
Encrypt |
Yes |
|
Shared block storage |
Multi-attach |
Yes |
|
Disk async replication |
Perform async replication |
|
|
Data protection |
Create snapshots and use instant access. |
Yes |
|
Create automatic snapshot policies. |
Yes |
|
|
Create cloud disks from snapshots. |
Yes |
|
|
Create snapshot-consistent groups. |
Yes Snapshot groups for Regional ESSDs can only include disks of the same type. |
|
|
Cloud disk operations |
Initialize cloud disks |
Yes |
|
Resize cloud disks |
Yes |
|
|
Roll back a cloud disk from a snapshot |
Yes |
|
|
Use as a system disk |
No Regional ESSDs can be used only as data disks. |
|
|
Attach a cloud disk to an ECS instance |
Yes |
|
|
Disk billing |
Change the billing method of a cloud disk |
Yes |
|
Disk specifications |
Change disk category |
Yes |
|
Performance elasticity |
Configure performance provisions |
No |
|
Configure burst performance |
No |
Specifications
The following table lists Regional ESSD specifications.
|
Metric |
Description |
|
Capacity range (GiB) |
10 to 65,536 |
|
Maximum IOPS per disk |
50,000 |
|
Maximum I/O size (KiB) |
16 |
|
Maximum throughput per disk (MB/s) |
350 |
|
Average random write latency per connection (ms) |
Several milliseconds① |
|
IOPS performance formula (Baseline Performance②) |
min{1,800 + 50 × Capacity, 50,000} |
|
Throughput performance formula (Baseline Performance, MB/s) |
min{120 + 0.5 × Capacity, 350} |
①Latency varies by region and availability zone. To test the average write latency, see Test for block storage devices.
②Baseline performance: The maximum IOPS and throughput a cloud disk provides after creation. Baseline performance scales linearly with disk capacity up to a maximum value that varies by disk specification.
Use Regional ESSDs
Create a Regional ESSD
Create a disk with an instance
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Go to the ECS instance buy page.
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Click the Custom Launch tab.
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Configure the billing method, region, instance type, and image. Note the following for Regional ESSDs:
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Select a region that supports Regional ESSDs.
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In the Storage section, set the data disk category to Regional ESSD and configure the disk size.
See Custom launch ECS instances for other parameters.
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Create a standalone disk
In the upper-left corner of the page, select a region and resource group.
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Click {value, select, create {Create {category}} createPrepaid {Add Subscription Disk} attach {Attach {category}} batchAttach {Attach {category}} }.
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Configure the parameters.
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Select a region that supports Regional ESSDs.
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Set the disk category to Regional ESSD and configure the disk size.
See Create a data disk for other parameters.
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Attach the new Regional ESSD to an ECS instance and initialize it before use.
See Attach a data disk.
Force attach a Regional ESSD
If a data center failure or ECS instance exception prevents you from detaching a Regional ESSD, force-attach it to another ECS instance in the same region without detaching first to accelerate service recovery.
Force attach is available only for Regional ESSDs. Other cloud disk types must be detached before attaching to another instance.
In the upper-left corner of the page, select a region and resource group.
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Find the disk that you want to attach and click {value, select, create {Create a disk} createPrepaid {Add Subscription Disk} snapshot {Create Snapshot} autoSnapshotPolicy {Configure Snapshot Policy} attach {Attach} batchAttach {Attach a disk} detach {Detach} release {Release} resize {Resize} category {Change Configuration} performanceLevel {Change Performance Level} changeToPostPaid {Switch to Pay-as-you-go} changeToPrePaid {Switch to Subscription} attribute {Edit Attributes} desc {Modify Description} reinit {Re-initialize Disk} partition {Partition Disk and Mount File Systems} consoleToCode {Generate IaC Deployment Template} other {{value}} } in the Actions column.
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Select the target instance and its release behavior. Select I confirm to move the disk to another instance by using the force attach feature, then follow the on-screen instructions to complete attachment and initialization.
After a force-attach, any data in the original instance's memory cache not yet written to disk is lost, and subsequent I/O requests from that instance fail.
References
To change the disk type for performance tuning or capacity expansion, see Modify a disk category.