The following sections provide an overview of Amazon EFS performance, and describe how your file system configuration impacts key performance dimensions. We also provide some important tips and recommendations for optimizing the performance of your file system.
Topics
Performance summary
File system performance is typically measured by using the dimensions of latency, throughput, and Input/Output operations per second (IOPS). Amazon EFS performance across these dimensions depends on your file system's configuration. The following configurations impact the performance of an Amazon EFS file system:
File system type – Regional or One Zone
Performance mode – General Purpose or Max I/O
Important
Max I/O performance mode has higher per-operation latencies than General Purpose performance mode. For faster performance, we recommend always using General Purpose performance mode. For more information, see Performance modes.
Throughput mode – Elastic, Provisioned, or Bursting
The following table outlines performance specifications for file systems using General Purpose performance mode and the possible different combinations of file system type and throughput mode.
| Storage and throughput configuration | Latency | Maximum IOPS | Maximum throughput | |||||
|---|---|---|---|---|---|---|---|---|
|
File system type |
Throughput mode |
Read operations |
Write operations |
Read operations |
Write operations |
Per-file-system read1 |
Per-file-system write1 |
Per-client read/write |
|
Regional |
Elastic |
As low as 250 microseconds (µs) |
As low as 2.7 milliseconds (ms) | 900,000–2,500,0002 | 500,0002 |
20–60 gibibytes per second (GiBps) |
1–5 GiBps |
1,500 mebibytes per second (MiBps)3 |
|
Regional |
Provisioned |
As low as 250 µs |
As low as 2.7 ms | 55,000 | 25,000 |
3–10 GiBps |
1–3.33 GiBps |
500 MiBps |
|
Regional |
Bursting |
As low as 250 µs |
As low as 2.7 ms | 35,000 | 7,000 |
3–5 GiBps |
1–3 GiBps |
500 MiBps |
|
One Zone |
Elastic, Provisioned, Bursting |
As low as 250 µs |
As low as 1.6 ms |
35,000 | 7,000 |
3 GiBps4 |
1 GiBps4 |
500 MiBps |
Note
Footnotes:
Maximum read and write throughput depend on the AWS Region. Throughput in excess of an AWS Region's maximum throughput requires a throughput quota increase. Any request for additional throughput is considered on a case-by-case basis by the Amazon EFS service team. Approval might depend on your type of workload. To learn more about requesting quota increases, see Amazon EFS quotas.
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By default, file systems that use Elastic throughput drive a maximum of 90,000 read IOPS for infrequently accessed data, 250,000 read IOPS for frequently accessed data, and 50,000 write IOPS. If your workload requires more IOPS, then you can request an increase of up to 10 times these numbers. For more information, see Amazon EFS quotas that you can increase. Additional recommendations apply to achieve maximum IOPS. For more information, see Optimizing workloads that demand high throughput and IOPS.
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The maximum combined read and write throughput is 1,500 MiBps for file systems using Elastic throughput and mounted using version 2.0 or later of the Amazon EFS client (amazon-efs-utils version) or the Amazon EFS CSI Driver (aws-efs-csi-driver). For all other file systems, the throughput limit is 500 MiBps. For more information about the Amazon EFS client, see Installing the Amazon EFS client.
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One Zone file systems that use Bursting throughput can drive the same per-file-system read and write throughput amounts as Regional file systems using Bursting throughput (maximum read of 5 GiBps for read and 3 GiBps for write).
Storage classes
Amazon EFS storage classes are designed for the most effective storage depending on use cases.
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EFS Standard storage class uses solid state drive (SSD) storage to deliver the lowest levels of latency for frequently accessed files. This storage class provides first-byte latencies as low as 250 microseconds for reads and 2.7 milliseconds for writes.
EFS Infrequent Access (IA) and EFS Archive storage classes store less frequently accessed data that doesn't require the latency performance that frequently accessed data requires. These storage classes provide first-byte latencies of tens of milliseconds.
For more information about EFS storage classes, see EFS storage classes.
Performance modes
Amazon EFS offers two performance modes, General Purpose and Max I/O.
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General Purpose mode has the lowest per-operation latency and is the default performance mode for file systems. One Zone file systems always use the General Purpose performance mode. For faster performance, we recommend always using General Purpose performance mode.
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Max I/O mode is a previous generation performance type that is designed for highly parallelized workloads that can tolerate higher latencies than the General Purpose mode. Max I/O mode is not supported for One Zone file systems or file systems that use Elastic throughput.
Important
Due to the higher per-operation latencies with Max I/O, we recommend using General Purpose performance mode for all file systems.
To help ensure that your workload stays within the IOPS limit available to file systems
using General Purpose performance mode, you can monitor the PercentIOLimit CloudWatch metric. For
more information, see CloudWatch metrics for Amazon EFS.
Applications can scale their IOPS elastically up to the limit associated with the performance mode. You are not billed separately for IOPS; they are included in a file system's throughput accounting. Every Network File System (NFS) request is accounted for as 4 kilobyte (KB) of throughput, or its actual request and response size, whichever is larger.
Throughput modes
A file system's throughput mode determines the throughput available to your file system. Amazon EFS offers three throughput modes: Elastic, Provisioned, and Bursting. Read throughput is discounted to allow you to drive higher read throughput than write throughput. The maximum throughput available with each throughput mode depends on the AWS Region. For more information about the maximum file system throughput in the different regions, see Amazon EFS quotas.
Your file system can achieve a combined 100% of its read and write throughput. For example, if your file system is using 33% of its read throughput limit, the file system can simultaneously achieve up to 67% of its write throughput limit. You can monitor your file system’s throughput usage in the Throughput utilization (%) graph on the on the File System Detail page of the console. For more information, see Monitoring throughput performance.
Choosing the correct throughput mode for a file system
Choosing the correct throughput mode for your file system depends on your workload's performance requirements.
Elastic throughput (Recommended) – Use the default Elastic throughput when you have spiky or unpredictable workloads and performance requirements that are difficult to forecast, or when your application drives throughput at an average-to-peak ratio of 5% or less. For more information, see Elastic throughput.
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Provisioned throughput – Use Provisioned throughput if you know your workload's performance requirements, or when your application drives throughput at an average-to-peak ratio of 5% or more. For more information, see Provisioned throughput.
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Bursting throughput – Use Bursting throughput when you want throughput that scales with the amount of storage in your file system.
If, after using Bursting throughput, you find that your application is throughput-constrained (for example, it uses more than 80% of the permitted throughput or you have used all of your burst credits), then you should use either Elastic or Provisioned throughput. For more information, see Bursting throughput.
For more information about Amazon EFS metrics, see CloudWatch metrics for Amazon EFS.
Elastic throughput
For file systems that are using Elastic throughput, Amazon EFS automatically scales throughput performance up or down to meet the needs of your workload activity. Elastic throughput is the best throughput mode for spiky or unpredictable workloads with performance requirements that are difficult to forecast, or for applications that drive throughput at 5% or less of the peak throughput on average (the average-to-peak ratio).
Because throughput performance for file systems with Elastic throughput scales automatically, you don't need to specify or provision the throughput capacity to meet your application needs. You pay only for the amount of metadata and data read or written, and you don't accrue or consume burst credits while using Elastic throughput.
Note
While Elastic throughput is designed to scale elastically with your throughput, we recommend implementing proper governance through monitoring metrics with CloudWatch (MeteredIOBytes) and usage alerts as part of your operational best practices. This helps you maintain optimal resource utilization and stay within your planned operational parameters. For more information, see Monitoring metrics with Amazon CloudWatch.
For information about per-Region Elastic throughput limits, see Amazon EFS quotas that you can increase.
Provisioned throughput
With Provisioned throughput, you specify a level of throughput that the file system can drive independent of the file system's size or burst credit balance. Use Provisioned throughput if you know your workload's performance requirements, or if your application drives throughput at 5% or more of the average-to-peak ratio.
For file systems using Provisioned throughput, you are charged for the amount of throughput enabled for the file system. The throughput amount billed in a month is based on the throughput provisioned in excess of your file system’s included baseline throughput from Standard storage, up to the prevailing Bursting baseline throughput limits in the AWS Region.
If the file system’s baseline throughput exceeds the Provisioned throughput amount, then it automatically uses the Bursting throughput allowed for the file system (up to the prevailing \Bursting baseline throughput limits in that AWS Region).
For information about per-RegionProvisioned throughput limits, see Amazon EFS quotas that you can increase.
Bursting throughput
Bursting throughput is recommended for workloads that require throughput that scales with the amount of storage in your file system. With Bursting throughput, the base throughput is proportionate to the file system's size in the Standard storage class, at a rate of 50 KiBps per each GiB of storage. Burst credits accrue when the file system consumes below its base throughput rate, and are deducted when throughput exceeds the base rate.
When burst credits are available, a file system can drive throughput up to 100 MiBps per TiB of storage, up to the AWS Region limit, with a minimum of 100 MiBps. If no burst credits are available, a file system can drive up to 50 MiBps per TiB of storage, with a minimum of 1 MiBps.
For information about per-Region Bursting throughput, see General resource quotas that cannot be changed.
Understanding Amazon EFS burst credits
With Bursting throughput, each file system earns burst credits over time at a baseline rate that is determined by the size of the file system that is stored in the EFS Standard storage class. The baseline rate is 50 MiBps per tebibyte [TiB] of storage (equivalent to 50 KiBps per GiB of storage). Amazon EFS meters read operations up to one-third the rate of write operations, permitting the file system to drive a baseline rate up to 150 KiBps per GiB of read throughput, or 50 KiBps per GiB of write throughput.
A file system can drive throughput at its baseline metered rate continuously. A file system accumulates burst credits whenever it is inactive or driving throughput below its baseline metered rate. Accumulated burst credits give the file system the ability to drive throughput above its baseline rate.
For example, a file system with 100 GiB of metered data in the Standard storage class has a baseline throughput of 5 MiBps. Over a 24-hour period of inactivity, the file system earns 432,000 MiB worth of credit (5 MiB × 86,400 seconds = 432,000 MiB), which can be used to burst at 100 MiBps for 72 minutes (432,000 MiB ÷ 100 MiBps = 72 minutes).
File systems larger than 1 TiB can always burst for up to 50 percent of the time if they are inactive for the remaining 50 percent of the time.
The following table provides examples of bursting behavior.
| File system size | Burst throughput | Baseline throughput |
|---|---|---|
| 100 GiB of metered data in Standard storage |
|
|
| 1 TiB of metered data in Standard storage |
|
|
| 10 TiB of metered data in Standard storage |
|
|
| Generally, larger file systems |
|
|
Note
Amazon EFS provides a metered throughput of 1 MiBps to all file systems, even if the baseline rate is lower.
The file system size used to determine the baseline and burst rates is the
ValueInStandard metered size available through the DescribeFileSystems API
operation.
File systems can earn credits up to a maximum credit balance of 2.1 TiB for file systems smaller than 1 TiB, or 2.1 TiB per TiB stored for file systems larger than 1 TiB. This behavior means that file systems can accumulate enough credits to burst for up to 12 hours continuously.
Restrictions on switching throughput and changing provisioned amount
You can switch an existing file system's throughput mode and change the throughput amount. However, after switching the throughput mode to Provisioned throughput or changing the Provisioned throughput amount, the following actions are restricted for a 24-hour period:
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Switching from Provisioned throughput mode to Elastic or Bursting throughput mode.
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Decreasing the Provisioned throughput amount.
