Merge pull request #97242 from btardif/master

Including info about the new File System Usage metric

Author: PRMerger18

articles/app-service/web-sites-monitor.md

@@ -21,7 +21,7 @@ ms.custom: seodec18
 [Azure App Service](https://go.microsoft.com/fwlink/?LinkId=529714) provides
 built-in monitoring functionality for web apps, mobile back ends, and API apps in the [Azure portal](https://portal.azure.com).
 
-In the Azure portal, you can review *quotas* and *metrics* for an app, review the App Service plan, and automatically set up *alerts* and *scaling* that are based on the metrics.
+In the Azure portal, you can review *quotas* and *metrics* for an app and App Service plan, and set up *alerts* and *auto-scaling* that are based metrics.
 
 ## Understand quotas
 
@@ -45,7 +45,7 @@ Quotas for Free or Shared apps are:
 | **Filesystem** | The total amount of storage allowed. |
 
 The only quota applicable to apps that are hosted in *Basic*, *Standard*, and
-*Premium* plans is Filesystem.
+*Premium* is Filesystem.
 
 For more information about the specific quotas, limits, and features available to the various App Service SKUs, see [Azure Subscription service limits](../azure-subscription-service-limits.md#app-service-limits).
 
@@ -63,6 +63,10 @@ You can increase or remove quotas from your app by upgrading your App Service pl
 
 ## Understand metrics
 
+> [!NOTE]
+> **File System Usage** is a new metric being rolled out globally, no data is expected unless you have been whitelisted for private preview.
+> 
+
 Metrics provide information about the app or the App Service plan's behavior.
 
 For an app, the available metrics are:
@@ -76,6 +80,7 @@ For an app, the available metrics are:
 | **Current Assemblies** | The current number of Assemblies loaded across all AppDomains in this application. |
 | **Data In** | The amount of incoming bandwidth consumed by the app, in MiB. |
 | **Data Out** | The amount of outgoing bandwidth consumed by the app, in MiB. |
+| **File System Usage** | Percentage of filesystem quota consumed by the app . |
 | **Gen 0 Garbage Collections** | The number of times the generation 0 objects are garbage collected since the start of the app process. Higher generation GCs include all lower generation GCs.|
 | **Gen 1 Garbage Collections** | The number of times the generation 1 objects are garbage collected since the start of the app process. Higher generation GCs include all lower generation GCs.|
 | **Gen 2 Garbage Collections** | The number of times the generation 2 objects are garbage collected since the start of the app process.|
@@ -89,7 +94,7 @@ For an app, the available metrics are:
 | **Http 4xx** | The count of requests resulting in an HTTP status code ≥ 400 but < 500. |
 | **Http Server Errors** | The count of requests resulting in an HTTP status code ≥ 500 but < 600. |
 | **IO Other Bytes Per Second** | The rate at which the app process is issuing bytes to I/O operations that do not involve data, such as control operations.|
-| **IO Other Operations Per Second** | The rate at which the app process is issuing I/O operations that are neither read nor write operations.|
+| **IO Other Operations Per Second** | The rate at which the app process is issuing I/O operations that are not read or write operations.|
 | **IO Read Bytes Per Second** | The rate at which the app process is reading bytes from I/O operations.|
 | **IO Read Operations Per Second** | The rate at which the app process is issuing read I/O operations.|
 | **IO Write Bytes Per Second** | The rate at which the app process is writing bytes to I/O operations.|