Key Metrics for Effective Storage Performance and Capacity Reporting - Response Impacts (7 of 10)

SAN or storage array performance problems can be identified at the host or backend storage environment.

The diagram below shows a typical performance impact in the more complex environment.

With SAN attached storage you can share storage across multiple servers, one of the downsides of this is that you can have storage response impact across multiple servers too.

Performance Capacity – Host Metrics

It's important that you understand the limitations of certain host metrics.

A selection of host metrics are shown below:

•        Measured response is the best metric for identifying trouble.

•        Host utilization only shows busy time, it doesn’t give capacity for SAN.

•        Physical IOPs is an important measure of throughput, all disks have their limitation.

•        Queue Length is a good indicator that a limitation has been reached somewhere.

Performance Capacity – Host Metrics

Metrics like host utilization can indicate impactful events, but ample capacity might still be available.

The high utilization can be seen generating large amounts of I/O in the chart below.

Queue lengths indicate that it may not currently be impacting response, but headroom is unknown. Response time is the key, as users will be impacted if it goes up.

On Wednesday I’ll be taking a look at array architecture.

Dale Feiste

Principal Consultant

Key Metrics for Effective Storage Performance and Capacity Reporting - Host Metrics (5 of 10)

Moving on to the metrics, for occupancy the key metric is utilization. How much storage are we using and how much is available?

Below are some host metrics that are typically available, these metrics are available at the file system, volume, or logical disk levels.

Array Metrics 

The illustration below shows an example of occupancy metrics from the array perspective. This is an example of Netapp filer aggregate metrics (down at the aggregate level).

A lot of these Storage arrays, from the different vendors, have different ways to carve up the storage.  Storage groups can be configured as in this example, using NetApp aggregates, which can have many occupancy metrics at different levels.

Some of the NetApp occupancy levels here are not available on the host in general.

I’ll pick out a few of the metrics:

De-dupe – If this is turned on you can find out how much space you’re saving

Total Committed space – A lot of vendors now offer thin provisioning where storage can be over-committed so it looks as though there is more storage than is really available, this allows you to see how over-committed you really are.

athene^®, our capacity management solution, brings in metrics from any data source so storage metrics can be part of the overall capacity management process.

On Friday I’ll be taking a look at Virtual Environments & Clusters.

Dale Feiste

Principal Consultant

Performance Capacity – Response Impacts - Key Metrics for Effective Storage Performance and Capacity Reporting (7 of 10)

SAN or storage array performance problems can be identified at the host or backend storage environment.

The diagram below shows a typical performance impact in the more complex environment.

 

With SAN attached storage you can share storage across multiple servers, one of the downsides of this is that you can have storage response impact across multiple servers too.

Performance Capacity – Host Metrics

It is important that you understand the limitations of certain host metrics.

A selection of host metrics are shown below:

•       Measured response is the best metric for identifying trouble.

•       Host utilization only shows busy time, it doesn’t give capacity for SAN.

•       Physical IOPs is an important measure of throughput, all disks have their limitation.

•       Queue Length is a good indicator that a limitation has been reached somewhere.

Performance Capacity – Host Metrics

Metrics like host utilization can indicate impactful events, but ample capacity might still be available.

 

The high utilization can be seen generating large amounts of I/O in the chart below.

Queue lengths indicate that it may not currently be impacting response, but headroom is unknown. Response time is the key, as users will be impacted if it goes up.

Next time I’ll look at array architecture. 
If you missed our recent webinar on Storage performance sign up for our Community and download or listen for free 
http://metron-athene.com/_downloads/on-demand-webinars/index_2.asp

Dale Feiste

Principal Consultant

Host Metrics - Key Metrics for Effective Storage Performance and Capacity Reporting (5 of 10)

Moving on to the metrics, for occupancy the key metric is utilization. How much storage are we using and how much is available?

Below are some host metrics that are typically available, these metrics are available at the file system, volume, or logical disk levels.

A lot of these Storage arrays, from the different vendors, have different ways to carve up the storage.  Storage groups can be configured as in this example, using NetApp aggregates, which can have many occupancy metrics at different levels.

Some of the NetApp occupancy levels here are not available on the host in general.

I’ll pick out a few of the metrics:

De-dupe – If this is turned on you can find out how much space you’re saving

Total Committed space – A lot of vendors now offer thin provisioning where storage can be over-committed so it looks as though there is more storage than is really available, this allows you to see how over-committed you really are.

athene^®, our capacity management solution, can bring in metrics from any time series data source so can allow storage metrics to be brought in to the capacity management process.

Next time I’ll be taking a look at Virtual Environments and Clusters. Don't forget to sign up for our next webinar 'Managing by KPI's' on February 18 http://metron-athene.com/services/training/webinars/index.html

Dale Feiste

Principal Consultant