Alibaba Cloud ESSD AutoPL disks are built on ESSDs, inheriting their features and performance while decoupling disk capacity from performance. When you configure an ESSD AutoPL disk's capacity, you can also customize its provisioned IOPS and throughput. This topic describes the features, specifications, billing, use cases, and configuration of ESSD AutoPL disks.
Workload on an ESSD AutoPL disk originates from its attached instance. Performance statistics reflect the activity of all applications on the instance that use the disk, such as Alibaba Cloud Security, Cloud Monitor, and Cloud Assistant, which run on the operating system.
For more information about disk performance metrics, see Performance metrics.
For more information about ESSDs, see ESSDs.
Cloud disk features
The total performance of an ESSD AutoPL disk is the sum of its baseline performance, provisioned performance, and performance burst:
Baseline performance
Baseline performance is the maximum IOPS and throughput included with a cloud disk at purchase. It increases linearly with disk capacity. The maximum baseline performance depends on the cloud disk's specifications.
Provisioned performance
You can specify and separately purchase the maximum IOPS and throughput for a cloud disk without changing its storage capacity. IOPS is the billing unit. Each provisioned IOPS adds 16 KB/s to the disk's throughput.
Performance burst
By default, performance burst is enabled for ESSD AutoPL disks. For services with fluctuating workloads, ESSD AutoPL disks can temporarily increase their performance to handle sudden I/O spikes. The performance returns to normal after the workload stabilizes. An ESSD AutoPL disk can deliver a maximum of 1,000,000 IOPS, 4 GB/s of throughput, and a performance density of 1,000 IOPS/GiB.
Scenarios
You can use ESSD AutoPL disks in the same scenarios as ESSD disks, such as for latency-sensitive applications or I/O-intensive workloads. Their flexible performance configuration and performance burst capabilities also make them ideal for the following scenarios:
Workloads that require higher performance at a fixed capacity.
Workloads that fluctuate significantly and experience frequent performance peaks.
ESSD AutoPL disk specifications
The following table describes the specifications of ESSD AutoPL disks.
Performance category | Property | Value |
Baseline performance | Capacity range (GiB) | 1 to 65,536 |
Maximum IOPS per disk | 50,000 | |
Maximum I/O size (KiB) | 16 | |
Maximum throughput per disk (MB/s) | 350 | |
Average latency of random writes (ms), Block Size=4k | 0.2 | |
IOPS formula per disk (baseline performance①) | max{min{1,800 + 50 * Capacity, 50,000}, 3,000} | |
Throughput formula per disk (baseline performance①, MB/s) | max{min{120 + 0.5 * Capacity, 350}, 125} | |
Provisioned performance | Maximum provisioned IOPS per disk② | 50,000 |
IOPS formula per disk (provisioned performance②) | Capacity (GiB) <= 3: Provisioned performance cannot be set. Capacity (GiB) >= 4: [1, min{(1,000 IOPS/GiB * Capacity - Baseline IOPS), 50,000}] | |
Throughput formula per disk (provisioned performance②, MB/s) | 16 KB * Provisioned IOPS/1,024 | |
Performance burst | Burst IOPS formula per disk (performance burst③) | Actual final IOPS - Baseline IOPS - Provisioned IOPS |
Burst throughput formula per disk (performance burst③) | Actual final throughput - Baseline throughput - Provisioned throughput | |
ESSD AutoPL disk performance | Performance composition | Baseline performance① + Provisioned performance② + Performance burst③ |
Maximum I/O density per disk④ | 1,000 IOPS/GiB | |
Maximum IOPS per disk (performance burst enabled) | Capacity <= 3 GiB: Performance burst is not supported. Capacity >= 4 GiB: min{1,000,000, 1,000 * Capacity} | |
Maximum throughput per disk (performance burst enabled) | Capacity <= 3 GiB: Performance burst is not supported. Capacity >= 4 GiB: max{min{16 KB * IOPS/1,024, 4 GB/s}, (Baseline throughput + Provisioned throughput)} | |
Maximum IOPS per disk (performance burst disabled) | 100,000 | |
Maximum throughput per disk (performance burst disabled) | 1,131 MB/s |
①: The maximum IOPS and throughput included with a disk upon purchase. This value increases linearly with the disk capacity. The maximum baseline performance depends on the disk specifications.
②: You can specify and separately purchase the maximum IOPS and throughput for a disk without changing its storage capacity. Provisioned performance is purchased in units of IOPS. Each provisioned IOPS adds 16 KB/s of throughput.
③: The additional performance a disk can provide beyond its baseline and provisioned performance. You can use CloudLens for EBS to monitor the burst details of an ESSD AutoPL disk in real time, including the burst duration and burst count (total burst I/O). For more information, see cloud disk analysis.
④: I/O density = IOPS/disk capacity. The unit is IOPS/GiB. This metric represents the IOPS capability per GiB.
The read and write performance of a disk is limited by both the instance type and the disk's specifications. The performance is capped when either limit is reached. For example, if an instance type limits the disk bandwidth to 6 Gbit/s (equivalent to 750 MB/s), the actual disk throughput will not exceed 750 MB/s.
For more information about the disk IOPS and bandwidth supported by different instance types, see instance family. If an instance type limits your disk's performance, consider upgrading the instance type.
For more information about the relationship between instance types and storage I/O performance, see instance types and storage I/O performance.
Supported instance families
ESSD AutoPL disks support the same instance families as ESSD disks. For more information, see Instance families.
Billing
Billable items and billing rules
The fees for an ESSD AutoPL disk consist of the following: disk capacity fee, provisioned performance fee, and performance burst fee. For more information about the billing rules, see Elastic Block Storage billing.
disk capacity fee: This fee is charged when you create the disk. The disk then provides the baseline performance of a PL1 ESSD.
provisioned performance fee: This pay-as-you-go fee is charged after you enable the provisioned performance feature.
performance burst fee: This pay-as-you-go fee is charged after you enable the performance burst feature.
You are not charged a performance burst fee if the total burst I/O per hour is 100,000 or less, as this is covered by a free quota of 100,000 I/Os.
If the total burst I/O per hour exceeds 100,000, a fee capping rule applies to prevent cost overruns. For more information, see Performance burst fee capping rules.
Performance burst fee capping rules
The fee capping rule for ESSD AutoPL disks prevents high burst IOPS from causing excessive charges. This rule keeps your performance burst fee predictable, even during periods of intense performance bursts.
Fee capping rule
The system caps the performance burst fee if the maximum burst I/O density (Maximum burst IOPS/Disk capacity) within a billing cycle exceeds 200 IOPS/GiB.
NoteBurst IOPS does not include baseline performance and provisioned performance.
Total burst I/O
Maximum burst density
Fee before capping
Fee after capping
Typical scenario
100,000 or less
Not applicable
Fee = Total burst I/O × Unit price of performance burst
Free (free quota of 100,000 I/Os)
Occasional I/O spikes
Greater than 100,000
200 or less
Not capped
Fee = (Burst I/O - 100,000) × Unit price of performance burst
Occasional business peaks below the IOPS capping threshold
Greater than 200
Capped
Fee = min((Burst I/O - 100,000) × Unit price of performance burst, disk capacity fee × 8)
Extreme workloads with high, sustained peak IOPS.
Cost savings comparison
For example, consider a 40 GiB ESSD AutoPL disk in the China (Hangzhou) region. In one hour, it has a total burst I/O of 4.39 million and its maximum burst I/O density reaches 230 IOPS/GiB. Because the density exceeds 200 IOPS/GiB, the fee cap applies. The performance burst fee is calculated as follows:
Fee comparison
Billing method
Performance burst fee
Fee before capping
Total burst I/O × Unit price of performance burst
4.39 million × 0.02 = CNY 8.78
Fee after capping
min((Burst I/O - 100,000) × Unit price of performance burst, disk capacity fee × 8)
min((4.39 million - 100,000) × 0.02, 8 × 40 × 0.0021) = CNY 0.672
You can view the performance burst fees and bill details for your ESSD AutoPL disks in the Billing Center. For more information, see bill query.
Pricing
For pricing details on ESSD AutoPL disks, see Elastic Block Storage pricing and the .
Impacts of overdue payments
If a pay-as-you-go payment for an ESSD AutoPL disk's provisioned performance or performance burst becomes overdue, Alibaba Cloud immediately stops those services. The baseline performance is not affected. These services resume immediately after you settle the overdue bill.
Provisioned performance and performance burst
You can create an ESSD AutoPL disk directly in the ECS console or when you create a new ECS instance.
To learn how to create an ECS instance and a disk, see Create an instance by using the wizard and Create an empty data disk.
After you create a disk, you can adjust its provisioned performance and performance burst settings based on your business needs to reduce costs. For more information, see Modify the performance configuration of an ESSD AutoPL disk.
The following steps describe how to create an ESSD AutoPL disk in the ECS console.
Go to ECS console - Block Storage.
In the top navigation bar, select the region and resource group of the resource that you want to manage.
Click Create Disk.
On the Create Disk page, configure the parameters for the disk.
Set ESSD AutoPL to ESSD AutoPL and specify the disk capacity.
Select Provisioned Performance Fee and specify the IOPS.
Enable Burst is selected by default. You can clear this option if you do not need it.
For information about other parameters, see Create an empty data disk.
ESSD AutoPL disk billing examples
The following examples show the performance metrics and fees for an ESSD AutoPL disk with provisioned performance and performance burst. These examples are for a disk in the China (Hangzhou) region with the following unit prices:
Subscription
Unit price of baseline performance: CNY 1.00 per 1 GiB/month
Unit price of provisioned performance: CNY 0.0000625 per 1 IOPS/hour
Unit price of performance burst: CNY 0.02 per 10,000 I/Os
Pay-as-you-go
Unit price of baseline performance: CNY 0.0021 per 1 GiB/hour
Unit price of provisioned performance: CNY 0.0000625 per 1 IOPS/hour
Unit price of performance burst: CNY 0.02 per 10,000 I/Os
The prices in this example are for reference only. For current pricing, refer to the Elastic Block Storage Pricing page.
Example 1: Provisioned performance without performance burst
In this example, a 100 GiB ESSD AutoPL disk is purchased from the ECS console with 200 IOPS of provisioned performance. The performance burst feature is disabled.
Disk billing method | Disk fee (CNY) | Disk performance |
Subscription
Subscription duration: 1 month |
|
|
Pay-as-you-go
Billing duration: 24 hours |
|
Example 2: Provisioned performance with performance burst
In this example, a 100 GiB ESSD AutoPL data disk is purchased from the ECS console with 200 IOPS of provisioned performance. The performance burst feature is enabled by default.
The disk fees and performance vary depending on the performance burst scenario.
Scenario 1: Only IOPS bursts occur
Assume that an IOPS burst of 8,000 occurs for 1 second. This burst exceeds the total baseline and provisioned performance. The total number of burst I/Os is 8,000. No performance burst fee is charged because the burst is within the free hourly quota of 100,000 I/Os.
Disk billing method
Disk fee (CNY)
Disk performance
Subscription
Baseline performance: subscription
Provisioned performance: pay-as-you-go
Performance burst: pay-as-you-go
Subscription duration: 1 month
Baseline performance fee: Disk capacity × Unit price × Subscription duration = 100 × 1 × 1 = 100
Provisioned performance fee: Unit price of provisioned performance × Provisioned IOPS × Subscription duration = 0.0000625 × 200 × (30 × 24) = 9
Performance burst fee: 0 (within the free quota of 100,000 I/Os)
Total fee: baseline performance fee + provisioned performance fee + performance burst fee = 100 + 9 + 0 = 109
IOPS:
Baseline IOPS: 1,800 + 50 × Capacity = 1,800 + 50 × 100 = 6,800
Provisioned IOPS: 200
Performance burst: 8,000 × 1 = 8,000
Total IOPS per disk: Baseline IOPS + Provisioned IOPS + Performance burst = 6,800 + 200 + 8,000 = 15,000
Throughput (MB/s):
Baseline throughput: 120 + 0.5 × Capacity = 120 + 0.5 × 100 = 170
Provisioned throughput: 16 KB × Provisioned IOPS/1,024 = 16 KB × 200/1,024 = 3.125
Total throughput per disk: Baseline throughput + Provisioned throughput = 170 + 3.125 = 173.125 (rounded for display in the console)
Pay-as-you-go
Baseline performance: pay-as-you-go
Provisioned performance: pay-as-you-go
Performance burst: pay-as-you-go
Billing duration: 24 hours
Baseline performance fee: Disk capacity × Unit price × Billing duration = 100 × 0.0021 × 24 = 5.04
Provisioned performance fee: Unit price of provisioned performance × Provisioned IOPS × Billing duration = 0.0000625 × 200 × 24 = 0.3
Performance burst fee: 0 (within the free quota of 100,000 I/Os)
Total fee: baseline performance fee + provisioned performance fee + performance burst fee = 5.04 + 0.3 + 0 = 5.34
Scenario 2: Only throughput bursts occur; no IOPS bursts occur
Assume a throughput burst of 1 GB/s occurs for 15 seconds. This burst exceeds the total baseline and provisioned performance. The burst throughput is equivalent to 65,536 I/Os per second (1 × 1,024 × 1,024 / 16 = 65,536). The total number of burst I/Os over 15 seconds is 65,536 × 15 = 983,040. For billing, this amount is rounded up to the nearest 10,000, resulting in 990,000 I/Os. Because the total burst I/O exceeds 100,000 and the I/O density is greater than 200 IOPS/GiB (maximum burst I/O density = 65,536/100 = 655.36 IOPS/GiB), the performance burst fee is capped.
Disk billing method
Disk fee (CNY)
Disk performance
Subscription
Baseline performance: subscription
Provisioned performance: pay-as-you-go
Performance burst: pay-as-you-go
Subscription duration: 1 month
Baseline performance fee: Disk capacity × Unit price × Subscription duration = 100 × 1 × 1 = 100
Provisioned performance fee: Unit price of provisioned performance × Provisioned IOPS × Subscription duration = 0.0000625 × 200 × (30 × 24) = 9
Performance burst fee: min((99 - 10) × 0.02, 100 × 0.0021 × 8) = 1.68
Total fee: baseline performance fee + provisioned performance fee + performance burst fee = 100 + 9 + 1.68 = 110.68
IOPS:
Baseline IOPS: 1,800 + 50 × Capacity = 1,800 + 50 × 100 = 6,800
Total IOPS per disk: Baseline IOPS + Provisioned IOPS = 6,800 + 200 = 7,000
Throughput (MB/s):
Baseline throughput: 120 + 0.5 × Capacity = 120 + 0.5 × 100 = 170
Provisioned throughput: 16 KB × Provisioned IOPS/1,024 = 16 KB × 200/1,024 = 3.125
Performance burst: 1 GB/s × 1,024 = 1,024
Total throughput per disk: Baseline throughput + Provisioned throughput + Performance burst = 170 + 3.125 + 1,024 = 1,197.125
Pay-as-you-go
Baseline performance: pay-as-you-go
Provisioned performance: pay-as-you-go
Performance burst: pay-as-you-go
Billing duration: 24 hours
Baseline performance fee: Disk capacity × Unit price × Billing duration = 100 × 0.0021 × 24 = 5.04
Provisioned performance fee: Unit price of provisioned performance × Provisioned IOPS × Billing duration = 0.0000625 × 200 × 24 = 0.3
Performance burst fee: min((99 - 10) × 0.02, 100 × 0.0021 × 8) = 1.68
Total fee: baseline performance fee + provisioned performance fee + performance burst fee = 5.04 + 0.3 + 1.68 = 7.02
Scenario 3: Both IOPS and throughput bursts occur, and billing is based on the larger number of burst I/Os.
Assume that an IOPS burst of 8,000 and a throughput burst of 1 GB/s both occur for 2 seconds. The total I/Os from the IOPS burst is 8,000 × 2 = 16,000. The total I/Os from the throughput burst is 1 × 1,024 × 1,024 / 16 × 2 = 131,072. Because the I/O count from the throughput burst is greater, this number is used for billing. This amount is rounded up to the nearest 10,000, resulting in 140,000 I/Os. Because the total burst I/O exceeds 100,000 and the I/O density is greater than 200 IOPS/GiB (maximum burst I/O density = 65,536/100 = 655.36 IOPS/GiB), the performance burst fee is capped.
Disk billing method
Disk fee (CNY)
Disk performance
Subscription
Baseline performance: subscription
Provisioned performance: pay-as-you-go
Performance burst: pay-as-you-go
Subscription duration: 1 month
Baseline performance fee: Disk capacity × Unit price × Subscription duration = 100 × 1 × 1 = 100
Provisioned performance fee: Unit price of provisioned performance × Provisioned IOPS × Subscription duration = 0.0000625 × 200 × (30 × 24) = 9
Performance burst fee: min((14 - 10) × 0.02, 100 × 0.0021 × 8) = 0.08
Total fee: baseline performance fee + provisioned performance fee + performance burst fee = 100 + 9 + 0.08 = 109.08
IOPS:
Baseline IOPS: 1,800 + 50 × Capacity = 1,800 + 50 × 100 = 6,800
Provisioned IOPS: 200
Performance burst: 8,000
Total IOPS per disk: Baseline IOPS + Provisioned IOPS + Performance burst = 6,800 + 200 + 8,000 = 15,000
Throughput (MB/s):
Baseline throughput: 120 + 0.5 × Capacity = 120 + 0.5 × 100 = 170
Provisioned throughput: 16 KB × Provisioned IOPS/1,024 = 16 KB × 200/1,024 = 3.125
Performance burst: 1 GB/s × 1,024 = 1,024
Total throughput per disk: Baseline throughput + Provisioned throughput + Performance burst = 170 + 3.125 + 1,024 = 1,197.125
Pay-as-you-go
Baseline performance: pay-as-you-go
Provisioned performance: pay-as-you-go
Performance burst: pay-as-you-go
Billing duration: 24 hours
Baseline performance fee: Disk capacity × Unit price × Billing duration = 100 × 0.0021 × 24 = 5.04
Provisioned performance fee: Unit price of provisioned performance × Provisioned IOPS × Billing duration = 0.0000625 × 200 × 24 = 0.3
Performance burst fee: min((14 - 10) × 0.02, 100 × 0.0021 × 8) = 0.08
Total fee: baseline performance fee + provisioned performance fee + performance burst fee = 5.04 + 0.3 + 0.08 = 5.42