Monitoring EFS with Amazon CloudWatch
You can monitor file systems using Amazon CloudWatch, which collects and processes raw data from Amazon EFS into readable, near realtime metrics. These statistics are recorded for a period of 15 months, so that you can access historical information and gain a better perspective on how your web application or service is performing. By default, Amazon EFS metric data is automatically sent to CloudWatch at 1minute periods. For more information about CloudWatch, see What Are Amazon CloudWatch, Amazon CloudWatch Events, and Amazon CloudWatch Logs? in the Amazon CloudWatch User Guide.
Amazon CloudWatch metrics for Amazon EFS
The AWS/EFS
namespace includes the following metrics.
BurstCreditBalance

The number of burst credits that a file system has. Burst credits allow a file system to burst to throughput levels above a file system’s baseline level for periods of time. For more information, see Throughput Scaling with Bursting Mode.
The
Minimum
statistic is the smallest burst credit balance for any minute during the period. TheMaximum
statistic is the largest burst credit balance for any minute during the period. TheAverage
statistic is the average burst credit balance during the period.Units: Bytes
Valid statistics:
Minimum
,Maximum
,Average
ClientConnections

The number of client connections to a file system. When using a standard client, there is one connection per mounted Amazon EC2 instance.
Note To calculate the average
ClientConnections
for periods greater than one minute, divide theSum
statistic by the number of minutes in the period.Units: Count of client connections
Valid statistics:
Sum
DataReadIOBytes

The number of bytes for each file system read operation.
The
Sum
statistic is the total number of bytes associated with read operations. TheMinimum
statistic is the size of the smallest read operation during the period. TheMaximum
statistic is the size of the largest read operation during the period. TheAverage
statistic is the average size of read operations during the period. TheSampleCount
statistic provides a count of read operations.Units:

Bytes for
Minimum
,Maximum
,Average
, andSum
. 
Count for
SampleCount
.
Valid statistics:
Minimum
,Maximum
,Average
,Sum
,SampleCount

DataWriteIOBytes

The number of bytes for each file write operation.
The
Sum
statistic is the total number of bytes associated with write operations. TheMinimum
statistic is the size of the smallest write operation during the period. TheMaximum
statistic is the size of the largest write operation during the period. TheAverage
statistic is the average size of write operations during the period. TheSampleCount
statistic provides a count of write operations.Units:

Bytes are the units for the
Minimum
,Maximum
,Average
, andSum
statistics. 
Count for
SampleCount
.
Valid statistics:
Minimum
,Maximum
,Average
,Sum
,SampleCount

MetadataIOBytes

The number of bytes for each metadata operation.
The
Sum
statistic is the total number of bytes associated with metadata operations. TheMinimum
statistic is the size of the smallest metadata operation during the period. TheMaximum
statistic is the size of the largest metadata operation during the period. TheAverage
statistic is the size of the average metadata operation during the period. TheSampleCount
statistic provides a count of metadata operations.Units:

Bytes are the units for the
Minimum
,Maximum
,Average
, andSum
statistics. 
Count for
SampleCount
.
Valid statistics:
Minimum
,Maximum
,Average
,Sum
,SampleCount

PercentIOLimit

Shows how close a file system is to reaching the I/O limit of the General Purpose performance mode. If this metric is at 100% more often than not, consider moving your application to a file system using the Max I/O performance mode.
Note This metric is only submitted for file systems using the General Purpose performance mode.
Units:

Percent

PermittedThroughput

The maximum amount of throughput a file system is allowed. For file systems in the Provisioned Throughput mode, if the amount of storage allows your file system to drive a higher amount of throughput than you provisioned, this metric will reflect the higher throughput instead of the provisioned amount. For file systems in the Bursting Throughput mode, this value is a function of the file system size and
BurstCreditBalance
. For more information, see Amazon EFS Performance.The
Minimum
statistic is the smallest throughput permitted for any minute during the period. TheMaximum
statistic is the highest throughput permitted for any minute during the period. TheAverage
statistic is the average throughput permitted during the period.Units: Bytes per second
Valid statistics:
Minimum
,Maximum
,Average
TotalIOBytes

The number of bytes for each file system operation, including data read, data write, and metadata operations.
The
Sum
statistic is the total number of bytes associated with all file system operations. TheMinimum
statistic is the size of the smallest operation during the period. TheMaximum
statistic is the size of the largest operation during the period. TheAverage
statistic is the average size of an operation during the period. TheSampleCount
statistic provides a count of all operations.Note To calculate the average operations per second for a period, divide the
SampleCount
statistic by the number of seconds in the period. To calculate the average throughput (Bytes per second) for a period, divide theSum
statistic by the number of seconds in the period.Units:

Bytes for
Minimum
,Maximum
,Average
, andSum
statistics. 
Count for
SampleCount
.
Valid statistics:
Minimum
,Maximum
,Average
,Sum
,SampleCount

Bytes reported in CloudWatch
As with Amazon S3 and Amazon EBS, Amazon EFS CloudWatch metrics are reported as raw Bytes. Bytes are not rounded to either a decimal or binary multiple of the unit. Keep this in mind when calculating your burst rate using the data you get from the metrics. For more information on bursting, see Throughput Scaling with Bursting Mode.
Amazon EFS dimensions
Amazon EFS metrics use the EFS
namespace and provide metrics for a single
dimension, FileSystemId
. A file system's ID can be found in the Amazon EFS
console, and it takes the form of fsXXXXXXXX
.