Monitor Azure File Sync metrics and health

Use Azure File Sync to centralize your organization's file shares in Azure Files, while keeping the flexibility, performance, and compatibility of an on-premises file server. Azure File Sync transforms Windows Server into a quick cache of your Azure file share. You can use any protocol that's available on Windows Server to access your data locally, including SMB, NFS, and FTPS. You can have as many caches as you need across the world.

This article describes how to monitor your Azure File Sync deployment by using Azure Monitor, Storage Sync Service, and Windows Server. It covers the following scenarios:

• View Azure File Sync metrics in Azure Monitor.
• Create alerts in Azure Monitor to proactively notify you of critical conditions.
• View health of your Azure File Sync deployment using the Azure portal.
• Use the event logs and performance counters on Windows Server to monitor the health of your Azure File Sync deployment.

Azure Monitor

Use Azure Monitor to view metrics and to configure alerts for sync, cloud tiering, and server connectivity.

Metrics

Metrics for Azure File Sync are enabled by default and are sent to Azure Monitor every 15 minutes.

How to view Azure File Sync metrics in Azure Monitor

1. Go to your Storage Sync Service in the Azure portal and click Metrics.
2. Click the Metric drop-down and select the metric you want to view.

The following metrics for Azure File Sync are available in Azure Monitor:

Metric name	Description
Bytes synced	Size of data transferred (upload and download). Unit: Bytes Aggregation Type: Average, Sum Applicable dimensions: Server Endpoint Name, Sync Direction, Sync Group Name
Cloud tiering cache hit rate	Percentage of bytes, not whole files, that have been served from the cache vs. recalled from the cloud. Unit: Percentage Aggregation Type: Average Applicable dimensions: Server Endpoint Name, Server Name, Sync Group Name
Cloud tiering recall size	Size of data recalled. Unit: Bytes Aggregation Type: Average, Sum Applicable dimensions: Server Name, Sync Group Name
Cloud tiering recall size by application	Size of data recalled by application. Unit: Bytes Aggregation Type: Average, Sum Applicable dimensions: Application Name, Server Name, Sync Group Name
Cloud tiering recall success rate	Percentage of recall requests that were successful. Unit: Percentage Aggregation Type: Average Applicable dimensions: Server Endpoint Name, Server Name, Sync Group Name
Cloud tiering recall throughput	Size of data recall throughput. Unit: Bytes Aggregation Type: Average, Sum, Maximum, Minimum Applicable dimensions: Server Name, Sync Group Name
Cloud tiering size of data tiered	Size of data tiered to Azure File Share. Unit: Bytes Aggregation Type: Average, Sum, Max, Min Applicable dimensions: Server Endpoint Name, Server Name, Sync Group Name
Cloud tiering size of data tiered by last maintenance job	Size of data tiered during last maintenance job. Unit: Bytes Aggregation Type: Sum, Average, Max, Min Applicable dimensions: Tiering Reason, Server Endpoint Name, Server Name, Sync Group Name
Cloud tiering low disk space mode	Indicates if the server endpoint is in low disk space mode or not (1=yes; 0=no) Unit: Count Aggregation Type: Sum, Max, Min, Count Applicable dimensions: Server Endpoint Name, Server Name, Sync Group Name
Files not syncing	Count of files that are failing to sync. Unit: Count Aggregation Types: Average Applicable dimensions: Server Endpoint Name, Sync Direction, Sync Group Name
Files synced	Count of files transferred (upload and download). Unit: Count Aggregation Type: Average, Sum Applicable dimensions: Server Endpoint Name, Sync Direction, Sync Group Name
Server cache size	Size of data cached on the server. Unit: Bytes Aggregation Type: Average, Maximum, Minimum Applicable dimension: Server Endpoint Name, Server Name, Sync Group Name
Cache data size by last access time	Size of data by last access time. Unit: Bytes Aggregation Type: Average, Max, Min Applicable dimension: Last Access Time, Server Endpoint Name, Server Name, Sync Group Name
Server online status	Count of heartbeats received from the server. Unit: Count Aggregation Type: Average, Count, Sum, Maximum, Minimum Applicable dimension: Server Name
Sync session result	Sync session result (1=successful sync session; 0=failed sync session) Unit: Count Aggregation Types: Average, Count, Sum, Maximum, Minimum Applicable dimensions: Server Endpoint Name, Sync Direction, Sync Group Name

Alerts

Alerts proactively notify you when important conditions are found in your monitoring data. To learn more about configuring alerts in Azure Monitor, see Overview of alerts in Azure.

How to create alerts for Azure File Sync

1. Go to your Storage Sync Service in the Azure portal.
2. Click Alerts in the Monitoring section and then click + New alert rule.
3. Click Select condition and provide the following information for the alert:
   • Metric
   • Dimension name
   • Alert logic
4. Click Select action group and add an action group (email, SMS, etc.) to the alert either by selecting an existing action group or creating a new action group.
5. Fill in the Alert details like Alert rule name, Description and Severity.
6. Click Create alert rule to create the alert.

The following table lists some example scenarios to monitor and the proper metric to use for the alert:

Scenario	Metric to use for alert
Server endpoint health shows an error in the portal	Sync session result
Files are failing to sync to a server or cloud endpoint	Files not syncing
Registered server is failing to communicate with the Storage Sync Service	Server online status
Cloud tiering recall size has exceeded 500GiB in a day	Cloud tiering recall size

For instructions on how to create alerts for these scenarios, see the Alert Examples section.

Storage Sync Service

To view the health of your Azure File Sync deployment in the Azure portal, navigate to the Storage Sync Service and the following information is available:

• Registered server health
• Server endpoint health
  • Persistent sync errors
  • Transient sync errors
  • Sync activity (Upload to cloud, Download to server)
  • Cloud tiering space savings
  • Tiering errors
  • Recall errors
• Metrics

Registered server health

To view the registered server health in the portal, navigate to the Registered servers section of the Storage Sync Service.

• If the Registered server state is Online, the server is successfully communicating with the service.
• If the Registered server state is Appears Offline, the Storage Sync Monitor process (AzureStorageSyncMonitor.exe) is not running or the server is unable to access the Azure File Sync service. See the troubleshooting documentation for guidance.

Server endpoint health

To view the health of a server endpoint in the portal, navigate to the Sync groups section of the Storage Sync Service and select a sync group.

• The server endpoint health and sync activity (Upload to cloud, Download to server) in the portal is based on the sync events that are logged in the Telemetry event log on the server (ID 9102 and 9302). If a sync session fails because of a transient error, such as error canceled, the server endpoint will still show as Healthy in the portal as long as the current sync session is making progress (files are applied). Event ID 9302 is the sync progress event and Event ID 9102 is logged once a sync session completes. For more information, see sync health and sync progress. If the server endpoint health shows a status other than Healthy, see the troubleshooting documentation for guidance.
• The Persistent sync errors and Transient sync errors count in the portal is based on the Event ID 9121 that is logged in the Telemetry event log on the server. This event is logged for each per-item error once the sync session completes. To view the errors in the portal, go to the Server Endpoint Properties and navigate to the Errors + troubleshooting section. To resolve per-item errors, see How do I see if there are specific files or folders that are not syncing?.
• The Cloud tiering space savings provides the amount of disk space saved by cloud tiering. The data provided for Cloud tiering space savings is based on Event ID 9071 that is logged in the Telemetry event log on the server. To view additional cloud tiering information and metrics, go to the Server Endpoint Properties and navigate to the Cloud tiering status section. To learn more, see Monitor cloud tiering.
• To view Tiering errors and Recall errors in the portal, go to the Server Endpoint Properties and navigate to the Errors + troubleshooting section. Tiering errors is based on Event ID 9003 that is logged in the Telemetry event log on the server and Recall errors is based on Event ID 9006. To investigate files that are failing to tier or recall, see How to troubleshoot files that fail to tier and How to troubleshoot files that fail to be recalled.

Metric charts

• The following metric charts are viewable in the Storage Sync Service portal:

  Metric name	Description	Blade name
  Bytes synced	Size of data transferred (upload and download).	Server endpoint - Sync status
  Files not syncing	Count of files that are failing to sync.	Server endpoint - Sync status
  Files synced	Count of files transferred (upload and download).	Server endpoint - Sync status
  Cloud tiering cache hit rate	Percentage of bytes, not whole files, that have been served from the cache vs. recalled from the cloud.	Server endpoint - Cloud tiering status
  Cache data size by last access time	Size of data by last access time.	Server endpoint - Cloud tiering status
  Cloud tiering size of data tiered by last maintenance job	Size of data tiered during last maintenance job.	Server endpoint - Cloud tiering status
  Cloud tiering recall size by application	Size of data recalled by application.	Server endpoint - Cloud tiering status
  Cloud tiering recall	Size of data recalled.	Server endpoint - Cloud tiering status, Registered servers
  Server online status	Count of heartbeats received from the server.	Registered servers

• To learn more, see Azure Monitor.

  Note

  The charts in the Storage Sync Service portal have a time range of 24 hours. To view different time ranges or dimensions, use Azure Monitor.

Windows Server

On the Windows Server that has the Azure File Sync agent installed, you can view the health of the server endpoints on that server using the event logs and performance counters.

Event logs

Use the Telemetry event log on the server to monitor registered server, sync, and cloud tiering health. The Telemetry event log is located in Event Viewer under Applications and Services\Microsoft\FileSync\Agent.

Sync health

• Event ID 9102 is logged once a sync session completes. Use this event to determine if sync sessions are successful (HResult = 0) and if there are per-item sync errors (PerItemErrorCount). For more information, see the sync health and per-item errors documentation.

  Note

  Sometimes sync sessions fail overall or have a non-zero PerItemErrorCount. However, they still make forward progress, and some files sync successfully. You can see this in the Applied fields such as AppliedFileCount, AppliedDirCount, AppliedTombstoneCount, and AppliedSizeBytes. These fields tell you how much of the session succeeded. If you see multiple sync sessions fail in a row, and they have an increasing Applied count, give sync time to try again before you open a support ticket.

• Event ID 9121 is logged for each per-item error once the sync session completes. Use this event to determine the number of files that are failing to sync with this error (PersistentCount and TransientCount). Persistent per-item errors should be investigated, see How do I see if there are specific files or folders that are not syncing?.

• Event ID 9302 is logged every 5 to 10 minutes if there's an active sync session. Use this event to determine how many items are to be synced (TotalItemCount), number of items that have synced so far (AppliedItemCount) and number of items that have failed to sync due to a per-item error (PerItemErrorCount). If sync is not making progress (AppliedItemCount=0), the sync session will eventually fail and an Event ID 9102 will be logged with the error. For more information, see the sync progress documentation.

Registered server health

• Event ID 9301 is logged every 30 seconds when a server queries the service for jobs. If GetNextJob finishes with status = 0, the server is able to communicate with the service. If GetNextJob finishes with an error, check the troubleshooting documentation for guidance.

Cloud tiering health

• To monitor tiering activity on a server, use Event ID 9003, 9016 and 9029 in the Telemetry event log, which is located in Event Viewer under Applications and Services\Microsoft\FileSync\Agent.

  • Event ID 9003 provides error distribution for a server endpoint. For example: Total Error Count and ErrorCode. One event is logged per error code.
  • Event ID 9016 provides ghosting results for a volume. For example: Free space percent is, Number of files ghosted in session, and Number of files failed to ghost.
  • Event ID 9029 provides ghosting session information for a server endpoint. For example: Number of files attempted in the session, Number of files tiered in the session, and Number of files already tiered.

• To monitor recall activity on a server, use Event ID 9005, 9006, 9009, 9059 and 9071 in the Telemetry event log, which is located in Event Viewer under Applications and Services\Microsoft\FileSync\Agent.

  • Event ID 9005 provides recall reliability for a server endpoint. For example: Total unique files accessed, and Total unique files with failed access.
  • Event ID 9006 provides recall error distribution for a server endpoint. For example: Total Failed Requests, and ErrorCode. One event is logged per error code.
  • Event ID 9009 provides recall session information for a server endpoint. For example: DurationSeconds, CountFilesRecallSucceeded, and CountFilesRecallFailed.
  • Event ID 9059 provides application recall distribution for a server endpoint. For example: ShareId, Application Name, and TotalEgressNetworkBytes.
  • Event ID 9071 provides cloud tiering efficiency for a server endpoint. For example: TotalDistinctFileCountCacheHit, TotalDistinctFileCountCacheMiss, TotalCacheHitBytes and TotalCacheMissBytes.

Performance counters

Use the Azure File Sync performance counters on the server to monitor sync activity.

To view Azure File Sync performance counters on the server, open Performance Monitor (Perfmon.exe). You can find the counters under the AFS Bytes Transferred and AFS Sync Operations objects.

The following performance counters for Azure File Sync are available in Performance Monitor:

Performance Object\Counter Name	Description
AFS Bytes Transferred\Downloaded Bytes/sec	Number of bytes downloaded per second.
AFS Bytes Transferred\Uploaded Bytes/sec	Number of bytes uploaded per second.
AFS Bytes Transferred\Total Bytes/sec	Total bytes per second (upload and download).
AFS Sync Operations\Downloaded Sync Files/sec	Number of files downloaded per second.
AFS Sync Operations\Uploaded Sync Files/sec	Number of files uploaded per second.
AFS Sync Operations\Total Sync File Operations/sec	Total number of files synced (upload and download).

Alert Examples

This section provides some example alerts for Azure File Sync.

How to create an alert if the server endpoint health shows an error in the portal

1. In the Azure portal, navigate to respective Storage Sync Service.
2. Go to the Monitoring section and select Alerts.
3. Select + New alert rule to create a new alert rule.
4. Configure condition by clicking Select condition.
5. Within Configure signal logic blade, select Sync session result under signal name.
6. Select the following dimension configuration:
   • Dimension name: Server Endpoint Name
   • Operator: =
   • Dimension values: All current and future values
7. Navigate to Alert Logic and complete the following:
   • Threshold set to Static
   • Operator: Less than
   • Aggregation type: Maximum
   • Threshold value: 1
   • Evaluated based on: Aggregation granularity = 24 hours | Frequency of evaluation = Every hour
   • Select Done.
8. Select Select action group to add an action group (email, SMS, etc.) to the alert either by selecting an existing action group or creating a new action group.
9. Fill in the Alert details like Alert rule name, Description, and Severity.
10. Select Create alert rule.

How to create an alert if files are failing to sync to a server or cloud endpoint

1. In the Azure portal, navigate to respective Storage Sync Service.
2. Go to the Monitoring section and select Alerts.
3. Select + New alert rule to create a new alert rule.
4. Configure condition by selecting Select condition.
5. Within Configure signal logic blade, select Files not syncing under signal name.
6. Select the following dimension configuration:
   • Dimension name: Server Endpoint Name
   • Operator: =
   • Dimension values: All current and future values
7. Navigate to Alert Logic and complete the following:
   • Threshold set to Static
   • Operator: Greater than
   • Aggregation type: Average
   • Threshold value: 100
   • Evaluated based on: Aggregation granularity = 5 minutes | Frequency of evaluation = Every 5 minutes
   • Click Done.
8. Select Select action group to add an action group (email, SMS, etc.) to the alert either by selecting an existing action group or creating a new action group.
9. Fill in the Alert details like Alert rule name, Description, and Severity.
10. Select Create alert rule.

How to create an alert if a registered server is failing to communicate with the Storage Sync Service

1. In the Azure portal, navigate to respective Storage Sync Service.
2. Go to the Monitoring section and select Alerts.
3. Select + New alert rule to create a new alert rule.
4. Configure condition by selecting Select condition.
5. Within Configure signal logic blade, select Server online status under signal name.
6. Select the following dimension configuration:
   • Dimension name: Server name
   • Operator: =
   • Dimension values: All current and future values
7. Navigate to Alert Logic and complete the following:
   • Threshold set to Static
   • Operator: Less than
   • Aggregation type: Maximum
   • Threshold value (in bytes): 1
   • Evaluated based on: Aggregation granularity = 1 hour | Frequency of evaluation = Every 30 minutes
     • Note that the metrics are sent to Azure Monitor every 15 to 20 minutes. Don't set the Frequency of evaluation to less than 30 minutes, as doing so will generate false alerts.
   • Select Done.
8. Select Select action group to add an action group (email, SMS, etc.) to the alert either by selecting an existing action group or creating a new action group.
9. Fill in the Alert details like Alert rule name, Description, and Severity.
10. Select Create alert rule.

How to create an alert if the cloud tiering recall size has exceeded 500 GiB in a day

1. In the Azure portal, navigate to respective Storage Sync Service.
2. Go to the Monitoring section and select Alerts.
3. Select + New alert rule to create a new alert rule.
4. Configure condition by selecting Select condition.
5. Within Configure signal logic blade, select Cloud tiering recall size under signal name.
6. Select the following dimension configuration:
   • Dimension name: Server name
   • Operator: =
   • Dimension values: All current and future values
7. Navigate to Alert Logic and complete the following:
   • Threshold set to Static
   • Operator: Greater than
   • Aggregation type: Total
   • Threshold value (in bytes): 67108864000
   • Evaluated based on: Aggregation granularity = 24 hours | Frequency of evaluation = Every hour
   • Select Done.
8. Select Select action group to add an action group (email, SMS, etc.) to the alert either by selecting an existing action group or creating a new action group.
9. Fill in the Alert details like Alert rule name, Description, and Severity.
10. Select Create alert rule.

Next steps

• Planning for an Azure File Sync deployment
• Consider firewall and proxy settings
• Deploy Azure File Sync
• Troubleshoot Azure File Sync