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Amazon EBS Metrics and Dimensions

Amazon EBS Metrics

Amazon Elastic Block Store (Amazon EBS) sends data points to CloudWatch for several metrics. Amazon EBS General Purpose SSD (gp2), Throughput Optimized HDD (st1) , Cold HDD (sc1), and Magnetic (standard) volumes automatically send five-minute metrics to CloudWatch. Provisioned IOPS SSD (io1) volumes automatically send one-minute metrics to CloudWatch. Data is only reported to CloudWatch when the volume is attached to an instance. For more information about how to monitor Amazon EBS, see Monitoring the Status of Your Volumes in the Amazon EC2 User Guide for Linux Instances.

The AWS/EBS namespace includes the following metrics.

Metric Description

VolumeReadBytes

VolumeWriteBytes

Provides information on the I/O operations in a specified period of time. The Sum statistic reports the total number of bytes transferred during the period. The Average statistic reports the average size of each I/O operation during the period, except on volumes attached to C5 instances, where the average represents the average over the specified period. The SampleCount statistic reports the total number of I/O operations during the period, except on volumes attached to C5 instances, where the sample count represents the number of data points used in the statistical calculation. Data is reported to CloudWatch only when the volume is active.

The Minimum and Maximum statistics on this metric are supported only by volumes attached to a C5 instance.

Units: Bytes

VolumeReadOps

VolumeWriteOps

The total number of I/O operations in a specified period of time.

To calculate the average I/O operations per second (IOPS) for the period, divide the total operations in the period by the number of seconds in that period.

The Minimum and Maximum statistics on this metric are supported only by volumes attached to a C5 instance.

Units: Count

VolumeTotalReadTime

VolumeTotalWriteTime

The total number of seconds spent by all operations that completed in a specified period of time. If multiple requests are submitted at the same time, this total could be greater than the length of the period. For example, for a period of 5 minutes (300 seconds): if 700 operations completed during that period, and each operation took 1 second, the value would be 700 seconds.

The Average statistic on this metric is not relevant for volumes attached to C5 instances.

The Minimum and Maximum statistics on this metric are supported only by volumes attached to a C5 instance.

Units: Seconds

VolumeIdleTime

The total number of seconds in a specified period of time when no read or write operations were submitted.

The Average statistic on this metric is not relevant for volumes attached to C5 instances.

The Minimum and Maximum statistics on this metric are supported only by volumes attached to a C5 instance.

Units: Seconds

VolumeQueueLength

The number of read and write operation requests waiting to be completed in a specified period of time.

The Sum statistic on this metric is not relevant for volumes attached to C5 instances.

The Minimum and Maximum statistics on this metric are supported only by volumes attached to a C5 instance.

Units: Count

VolumeThroughputPercentage

Used with Provisioned IOPS SSD volumes only. The percentage of I/O operations per second (IOPS) delivered of the total IOPS provisioned for an Amazon EBS volume. Provisioned IOPS SSD volumes deliver within 10 percent of the provisioned IOPS performance 99.9 percent of the time over a given year.

During a write, if there are no other pending I/O requests in a minute, the metric value will be 100 percent. Also, a volume's I/O performance may become degraded temporarily due to an action you have taken (for example, creating a snapshot of a volume during peak usage, running the volume on a non-EBS-optimized instance, or accessing data on the volume for the first time).

Units: Percent

VolumeConsumedReadWriteOps

Used with Provisioned IOPS SSD volumes only. The total amount of read and write operations (normalized to 256K capacity units) consumed in a specified period of time.

I/O operations that are smaller than 256K each count as 1 consumed IOPS. I/O operations that are larger than 256K are counted in 256K capacity units. For example, a 1024K I/O would count as 4 consumed IOPS.

Units: Count

BurstBalance

Used with General Purpose SSD (gp2), Throughput Optimized HDD (st1), and Cold HDD (sc1) volumes only. Provides information about the percentage of I/O credits (for gp2) or throughput credits (for st1 and sc1) remaining in the burst bucket. Data is reported to CloudWatch only when the volume is active. If the volume is not attached, no data is reported.

The Sum statistic on this metric is not relevant for volumes attached to C5 instances.

Units: Percent

Dimensions for Amazon EBS Metrics

The only dimension that Amazon EBS sends to CloudWatch is VolumeId. All available statistics are filtered by VolumeId.