Docs

Elastic Compute Service

User Guide

Local volume

A local volume is a hardware device that is deployed on the physical server (host) where the ECS instance resides. Local volumes function as local storage devices for ECS instances and provide low latency, high IOPS for random reads and writes, high I/O throughput, and high cost-efficiency. Local volumes are applicable for scenarios that require high I/O capabilities and fast data exchange and processing.

Usage notes

Local volumes reside on a single physical server where the ECS instance is deployed. The data reliability of a local volume depends on the reliability of the physical server. Therefore, local volumes may encounter single points of failures (SPOFs).

warning

When the physical server of the ECS instance is down or the local volume is damaged, the data stored on the local volume may be lost. Do not store business data that requires long-term storage on local volumes, and back up it timely.

We strongly recommend that you use a high-availability architecture and deploy your services on multiple instances, or enable the cloud volume for data backup. These measures ensure high availability of your services and data reliability.

We strongly recommend that you store the data on a cloud volume for long-term use.

The specifications and lifecycle of local volumes depend on the ECS instance types cannot be purchased separately. Local volumes cannot be separately mounted, unmounted, or scaled up.

For ECS instances that have local volumes, you can not change the instance type (including vCPU and memory).

Local volume type

tip

This topic introduces information about local volumes currently sold with ECS instances. To learn more about instance performance and applicable scenarios, refer to Instance type overview.

The following table describes the local volume types and the matching ECS instance type families.

Local volume type	Matching ECS instance type family	Scenarios
Local NVMe SSD	Local SSD EBM: ebmg4id, ebmg3id, ebmg3ad, ebmc3id, ebmc3ad, ebmr3id, ebmi3s, ebmi2 HPC-optimized: ebmhpcpni2l, hpcpni2, ebmhpcpni2, ebmhpchfpni2 HPC CPU: ebmhpcg3ad	Assume that the ECS instance type family is local SSD, local NVMe SSDs are applicable for the following scenarios: Business scenarios involving I/O-intensive applications that feature high availability architecture at the application layer, such as relational databases, NoSQL, and ElasticSearch.
Local SATA HDD	Big Data	Local SATA HDDs are applicable for big data services involving large-scale data storage and offline computing tasks, such as EMR. These services are inherently insensitive to latency and can tolerate SPOFs because data redundancy is enabled on the upper layer.

Performance of local volume

See the following sections for the performance data of local volumes attached to instances of certain types. You can test the performance of local volumes such as throughput and IOPS by referring to the Testing local volume performance document. This way, you can verify the standard performance data provided by the platform.

Local SSD

The following tables show the performance of local SSDs attached to Local SSD ECS instances.

Local SSD i4ag

NVMe SSD metric	ecs.i4ag.12xlarge	ecs.i4ag.16xlarge	ecs.i4ag.24xlarge	ecs.i4ag.32xlarge	ecs.i4ag.48xlarge
Maximum read IOPS (10,000)	270	270	540	540	1,080
Maximum read throughput (GB/s)	13	13	26	26	52
Maximum write throughput (GB/s)	5.5	5.5	11	11	22

Local SSD i3s

tip

To use ecs.i3s.48xlarge, contact your account manager.

NVMe SSD metric	ecs.i3s.3xlarge	ecs.i3s.6xlarge	ecs.i3s.12xlarge	ecs.i3s.24xlarge	ecs.i3s.48xlarge
Maximum read IOPS (10,000)	100	200	400	800	1,600
Maximum read throughput (GB/s)	6.5	13	26	52	104
Maximum write throughput (GB/s)	3.5	7	14	28	56

Local SSD i2g (Discontinued)

tip

Local SSD i2g has been discontinued. We recommend you select Local SSD i3s.

NVMe SSD metric	ecs.i2g.2xlarge	ecs.i2g.4xlarge	ecs.i2g.8xlarge	ecs.i2g.12xlarge	ecs.i2g.14xlarge	ecs.i2g.16xlarge	ecs.i2g.28xlarge
Maximum read IOPS (10,000)	32	64	128	192	256	256	512
Maximum read throughput (GB/s)	1.6	3.2	6.4	9.6	12.8	12.8	25.6
Maximum write throughput (GB/s)	0.7	1.4	2.8	4.2	5.6	5.6	11.2

Local SSD i2 (Discontinued)

tip

Local SSD i2 has been discontinued. We recommend you select Local SSD i3s.

NVMe SSD metric	ecs.i2.3xlarge	ecs.i2.4xlarge	ecs.i2.8xlarge	ecs.i2.14xlarge	ecs.i2.28xlarge
Maximum read IOPS (10,000)	75	75	150	300	600
Maximum read throughput (GB/s)	6.5	6.5	13	26	52
Maximum write throughput (GB/s)	3.3	3.3	6.6	13.2	26.4

Local HDD

The following tables show the performance of local HDDs attached to Big Data instances.

Big Data d4c

SATA HDD metric	ecs.d4c.4xlarge	ecs.d4c.7xlarge	ecs.d4c.14xlarge/ecs.d4cd.14xlarge	ecs.d4c.28xlarge/ecs.d4cd.28xlarge
HDD quantity (volume)	3	6	12	24
Maximum throughput (MiB/s)	770	1540	3080	6160
Maximum capacity (GB)	24	48	96	192

Big Data d4s

SATA HDD metric	ecs.d4s.4xlarge	ecs.d4s.7xlarge	ecs.d4s.14xlarge/ecs.d4sd.14xlarge	ecs.d4s.28xlarge/ecs.d4sd.28xlarge
HDD quantity (volume)	3	6	12	24
Maximum throughput (MiB/s)	815	1630	3260	6520
Maximum HDD capacity (GB)	72	144	288	576