Promo Center

50% off for new user

Direct Mail-46% off

Learn More
This topic was translated by AI and is currently in queue for revision by our editors. Alibaba Cloud does not guarantee the accuracy of AI-translated content. Request expedited revision

Storage types

Updated at: 2025-02-17 03:04

ApsaraDB RDS offers various data storage types: ESSD, local SSD, standard SSD. This topic describes the key characteristics, differences, and recommendations for purchasing these storage types.

Storage type description

Storage type

Description

Supported engines

Storage type

Description

Supported engines

ESSD

Enhanced SSDs (ESSDs) are newly launched ultra-high performance disks by Alibaba Cloud. ESSDs are based on the next-generation distributed block storage architecture and integrated with 25GE network and RDMA technology. They provide up to 1 million random read/write capabilities per disk and lower one-way latency than standard SSDs. ESSDs are available in the following performance levels:

  • ESSD PL1: PL1 performance level ESSD.

  • ESSD PL2: Compared with PL1, PL2 performance level ESSDs deliver approximately 2 times the IOPS and throughput.

  • ESSD PL3: Compared with PL1, PL3 performance level ESSDs deliver up to 20 times the IOPS and 11 times the throughput. They are suitable for scenarios that require extremely high concurrent I/O performance and stable read/write latency.

For more information about the performance of ESSDs, see ESSD.

MySQL, PostgreSQL, SQL Server, MariaDB

Local SSD

Local SSDs reside on the same physical host as the database engine that is run by your RDS instance. You can store data in local SSDs to reduce I/O latencies.

MySQL

Standard SSD

Standard SSDs are elastic block storage devices that are designed based on a distributed storage architecture. You can store data in standard SSDs to separate computing from storage.

Note

Standard SSDs are being phased out. We recommend that you use ESSDs. For more information, see [Discontinued/Offline] Some RDS instances no longer provide standard SSDs for sale as of July 1, 2022.

MySQL, PostgreSQL, SQL Server, MariaDB

For a performance comparison among storage types (single disk capacity, maximum IOPS, maximum throughput, etc.), see block storage performance.

Note

All mentioned storage types fulfill the reliability, durability, and read/write performance standards outlined in the ApsaraDB RDS SLA.

  • Local SSDs: RDS instances utilizing these are built on a primary-secondary architecture (High-availability Edition). In case of primary node failure, a switchover occurs within seconds.

  • Cloud disks (standard SSDs, ESSDs): These distributed cloud disks maintain data reliability through multiple redundant copies. If the RDS instance is a high-availability or cluster edition, a switchover happens within seconds in case of failure.

View storage types

You can view the storage type of an instance on the Basic Information page of the instance.

image.png

Comparison among storage types

Note

Currently, only RDS MySQL High-availability Edition instances support local SSDs.

Comparison Item

ESSD

Local SSD

Comparison Item

ESSD

Local SSD

I/O performance

Note

The speed and efficiency of a disk in processing data read/write requests, including IOPS, throughput, and access latency.

★★★★★

Significantly improved compared with standard SSDs:

  • IOPS: Varies based on disk specifications and instance types.

  • I/O Latency: Ranges from 100 to 200 microseconds.

★★★★★

Low I/O latency and high performance:

  • IOPS: Varies based on instance types.

  • I/O Latency: Ranges from 10 to 50 microseconds.

Configuration flexibility

★★★★★

Offers a range of configuration options and enables storage capacity expansion or reduction for an RDS instance.

Note

Scale-in is supported only for certain MySQL and PostgreSQL instances under specific conditions. For more information, see Overview of Instance Changes and Change Configuration.

★★★★

Offers a range of configuration options with the ability to adjust storage capacity separately. The storage capacity for some RDS instances using local SSDs depends on the instance types, and these RDS instances do not support separate storage capacity adjustments.

Backup method

ESSD snapshot backup.

Xtrabackup physical backup.

Time required for backup, read-only instance creation, and instance cloning

★★★★★

Takes only a few seconds.

★★

Can take several hours, depending on the disk space.

Time required for storage capacity expansion

★★★★★

  • RDS MySQL, RDS PostgreSQL, RDS MariaDB: Supports online storage capacity expansion, completing within a few seconds.

  • RDS SQL Server: Expansion takes a few minutes.

★★★

Requires several hours to copy data during storage capacity scaling.

Impact of storage capacity expansion

  • RDS MySQL, RDS PostgreSQL, RDS MariaDB: No impact on operations.

  • RDS SQL Server: May cause transient connections.

Expansion triggers transient connections.

Data durability

★★★★★

Ensures 99.9999999% data reliability and supports RDS Basic Edition for cost-effective solutions.

★★★★

Risk of data corruption due to hardware faults; requires secondary databases for disaster recovery.

Purchase suggestions

We recommend starting with ESSDs.

Product support

For detailed information on storage types and supported features across different database engines, refer to the following documents:

FAQ

FAQ about Storage Space

  • On this page (1, M)
  • Storage type description
  • View storage types
  • Comparison among storage types
  • Purchase suggestions
  • Product support
  • FAQ
Feedback
phone Contact Us

Chat now with Alibaba Cloud Customer Service to assist you in finding the right products and services to meet your needs.

alicare alicarealicarealicare