Amazon CloudWatch metrics for Amazon EBS
Amazon CloudWatch metrics are statistical data that you can use to view, analyze, and set alarms on the operational behavior of your volumes.
Data is available automatically in 1-minute periods at no charge.
When you get data from CloudWatch, you can include a Period request parameter to
specify the granularity of the returned data. This is different than the period that we use
when we collect the data (1-minute periods). We recommend that you specify a period in your
request that is equal to or greater than the collection period to ensure that the returned
data is valid.
You can get the data using either the CloudWatch API or the Amazon EC2 console. The console takes the raw data from the CloudWatch API and displays a series of graphs based on the data. Depending on your needs, you might prefer to use either the data from the API or the graphs in the console.
Amazon EBS metrics
Amazon Elastic Block Store (Amazon EBS) sends data points to CloudWatch for several metrics. All Amazon EBS volume types automatically send 1-minute metrics to CloudWatch, but only when the volume is attached to an instance.
Metrics
Volume metrics for volumes attached to all instance types
The AWS/EBS namespace includes the following metrics for EBS volumes that
are attached to all instance types. To get information about the available disk space from
the operating system on an instance, see View free disk space.
Note
-
Some metrics have differences on instances that are built on the Nitro System. For a list of these instance types, see Instances built on the Nitro System.
-
The
AWS/EC2namespace includes additional Amazon EBS metrics for volumes that are attached to Nitro-based instances that are not bare metal instances. For more information about these metrics see, Amazon EBS metrics for Nitro-based instances.
| Metric | Description |
|---|---|
VolumeReadBytes |
Provides information on the read operations in a specified
period of time. The The Units: Bytes |
VolumeWriteBytes |
Provides information on the write operations in a specified
period of time. The The Units: Bytes |
VolumeReadOps |
The total number of read operations in a specified period of time. Note: read operations are counted on completion. To calculate the average read operations per second (read IOPS) for the period, divide the total read operations in the period by the number of seconds in that period. The Units: Count |
VolumeWriteOps |
The total number of write operations in a specified period of time. Note: write operations are counted on completion. To calculate the average write operations per second (write IOPS) for the period, divide the total write operations in the period by the number of seconds in that period. The Units: Count |
VolumeTotalReadTime |
NoteThis metric is not supported with Multi-Attach enabled volumes. The total number of seconds spent by all read 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 1 minutes (60 seconds): if 150 operations completed during that period, and each operation took 1 second, the value would be 150 seconds. For Xen instances, data is reported only when there is read activity on the volume. The The Units: Seconds |
VolumeTotalWriteTime |
NoteThis metric is not supported with Multi-Attach enabled volumes. The total number of seconds spent by all write 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 1 minute (60 seconds): if 150 operations completed during that period, and each operation took 1 second, the value would be 150 seconds. For Xen instances, data is reported only when there is write activity on the volume. The The Units: Seconds |
VolumeIdleTime |
NoteThis metric is not supported with Multi-Attach enabled volumes. The total number of seconds in a specified period of time when no read or write operations were submitted. The The Units: Seconds |
VolumeQueueLength |
The number of read and write operation requests waiting to be completed in a specified period of time. The The Units: Count |
VolumeThroughputPercentage |
NoteThis metric is not supported with Multi-Attach enabled volumes. 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 their provisioned performance 99.9 percent of the time. 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 ( The If the baseline performance of the volume exceeds the maximum burst performance, credits are never spent. If the volume is attached to an instance built on the Nitro System, the burst balance is not reported. For other instances, the reported burst balance is 100%. For more information, see gp2 volume performance. Units: Percent |
Volume metrics for volumes attached to Nitro-based instance types
The AWS/EC2 namespace includes additional Amazon EBS metrics for volumes
that are attached to Nitro-based instances that are not bare metal instances. For
more information about these metrics see, Amazon EBS metrics for Nitro-based instances.
Fast snapshot restore metrics
AWS/EBS namespace includes the following metrics for fast snapshot restore.
| Metric | Description |
|---|---|
FastSnapshotRestoreCreditsBucketSize |
The maximum number of volume create credits that can be accumulated. This metric is reported per snapshot per Availability Zone. The most meaningful statistic is Units: Count |
FastSnapshotRestoreCreditsBalance |
The number of volume create credits available. This metric is reported per snapshot per Availability Zone. The most meaningful statistic is Units: Count |
Dimensions for Amazon EBS metrics
The supported dimension is the volume ID (VolumeId). All available statistics are filtered by volume ID.
For the volume metrics, the supported dimension
is the volume ID (VolumeId). All available statistics are filtered by volume ID.
For the fast snapshot restore metrics,
the supported dimensions are the snapshot ID (SnapshotId) and the
Availability Zone (AvailabilityZone).
Graphs in the Amazon EC2 console
After you create a volume, you can view the volume's monitoring graphs in the Amazon EC2 console. Select a volume on the Volumes page in the console and choose Monitoring. The following table lists the graphs that are displayed. The column on the right describes how the raw data metrics from the CloudWatch API are used to produce each graph. The period for all the graphs is 5 minutes.
| Graph | Description using raw metrics |
|---|---|
|
Read throughput (KiB/s) |
Sum(VolumeReadBytes) / Period / 1024 |
|
Write throughput (KiB/s) |
Sum(VolumeWriteBytes) / Period / 1024 |
|
Read operations (Ops/s) |
Sum(VolumeReadOps) / Period |
|
Write operations (Ops/s) |
Sum(VolumeWriteOps) / Period
|
|
Average queue length (Operations) |
Avg(VolumeQueueLength)
|
|
Time spent idle (%) |
Sum(VolumeIdleTime) / Period × 100
|
|
Average read size (KiB/op) |
For Nitro-based instances, the following formula derives Average Read Size using CloudWatch Metric Math:
The |
|
Average write size (KiB/op) |
For Nitro-based instances, the following formula derives Average Write Size using CloudWatch Metric Math:
The |
|
Average read latency (ms/op) |
For Nitro-based instances, the following formula derives Average Read Latency using CloudWatch Metric Math:
The |
|
Average write latency (ms/op) |
For Nitro-based instances, the following formula derives Average Write Latency using CloudWatch Metric Math:
The |
For the average latency graphs and average size graphs, the average is calculated over the total number of operations (read or write, whichever is applicable to the graph) that completed during the period.