How to use Amazon FSx for Lustre metrics
The metrics reported by Amazon FSx for Lustre provide information that you can analyze in different ways. The list following shows some common uses for the metrics. These are suggestions to get you started, not a comprehensive list.
How Do I Determine...  Relevant Metrics 

My file system's throughput? 
SUM(DataReadBytes + DataWriteBytes)/Period (in seconds) 
My file system's IOPS? 
Total IOPS = SUM(DataReadOperations + DataWriteOperations + MetadataOperations)/Period (in seconds) 
My file system's data compression ratio? 
SUM(LogicalDiskUsage) / SUM(PhysicalDiskUsage) 
Metric math: Data compression ratio
Using metric math, you can query multiple CloudWatch metrics and use math expressions to create new time series based on these metrics. You can visualize the resulting time series in the CloudWatch console and add them to dashboards. For more information on metric math, see Use Metric Math in the Amazon CloudWatch User Guide.
This metric math expression calculates the data compression ratio of your Amazon FSx for Lustre
file system. To calculate this ratio, first get the sum statistic of the total logical
disk usage (without compression), which is provided by the LogicalDiskUsage
metric. Then divide that by the sum statistic of the total physical disk usage (with
compression), provided by the PhysicalDiskUsage
metric.
So if your logic is this: sum of LogicalDiskUsage
÷ sum
of PhysicalDiskUsage
Then your CloudWatch metric information is the following.
ID  Usable metric  Statistic  Period 

m1  LogicalDiskUsage

Sum  1 minute 
m2  PhysicalDiskUsage 
Sum  1 minute 
Your metric math ID and expression are the following.
ID  Expression 

e1  m1/m2 
e1
is the data compression ratio.