PRTG Manual: SSH Disk Free Sensor
The SSH Disk Free sensor monitors free space on disks of a Linux/Unix system using Secure Shell (SSH).
The sensor can show the following:
- Free disk space in bytes for every mounted partition
- Free disk space in percent for every mounted partition
- Total disk space
The free space returned by this sensor shows the available disk space of the volume, minus a reserve defined for this volume (for example, for redundancy purposes). So, this sensor shows the disk space that is actually available for use. The size of the reserved disk space can be defined with tune2fs. For details, see the Knowledge Base: Why do SSH Disk Free and SNMP Linux Disk Free show different values for my target Linux system?
- Dutch: SSH Disk vrij
- French: Espace disque disponible SSH
- German: SSH Laufwerkskapazität
- Japanese: SSH ディスク空き容量
- Portuguese: SSH Disco livre
- Russian: Свободное пространство диска по SSH
- Simplified Chinese: SSH 磁盘可用空间
- Spanish: SSH disco libre
- This sensor requires credentials for Linux/Solaris/macOS (SSH/WBEM) systems in the settings of the parent device.
- This sensor cannot support all Linux/Unix and macOS distributions.
- This sensor has a medium performance impact.
- See the Knowledge Base: SSH and SFTP Sensors in Unknown Status
The Add Sensor dialog appears when you manually add a new sensor to a device. It only shows the setting fields that are required for creating the sensor. Therefore, you do not see all setting fields in this dialog. You can change (nearly) all settings in the sensor's Settings tab later.
Select the disks that you want to monitor. PRTG creates one sensor for each disk that you select in the Add Sensor dialog. The settings you select are valid for all sensors that you create when you finish this dialog.
The following settings in the Add Sensor dialog differ in comparison to the sensor's Settings tab.
SSH Disk Free
Setting |
Description |
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Disks |
Select the partitions that you want to monitor. You see a list with the names of all items that are available for monitoring. Select the desired items by adding check marks in front of the respective lines. PRTG creates two channels for each selection. You can also select all items or cancel the selection by using the check box in the table header.
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Click the Settings tab of a sensor to change its settings.
Usually, a sensor connects to the IP Address or DNS Name of the parent device on which you created the sensor. See the device settings for details. For some sensors, you can explicitly define the monitoring target in the sensor settings. See below for details on available settings.
Setting |
Description |
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Sensor Name |
Enter a meaningful name to identify the sensor. By default, PRTG shows this name in the device tree, as well as in alarms, logs, notifications, reports, maps, libraries, and tickets.
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Parent Tags |
Shows tags that the sensor inherits from its parent device, parent group, and parent probe. This setting is shown for your information only and cannot be changed here. |
Tags |
Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.
The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:
|
Priority |
Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority ( |
Setting |
Description |
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Connection Timeout (Sec.) |
Define a timeout in seconds for the connection. This is the time that the sensor waits to establish a connection to the host. Keep this value as low as possible. The maximum value is 900 seconds (15 minutes). Enter an integer value.
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Shell Timeout (Sec.) |
Define a timeout in seconds for the shell response. This is the time in seconds the sensor waits for the shell to return a response after k has sent its specific command (for example, cat /proc/loadavg). The maximum value is 300 seconds (5 minutes). Enter an integer value.
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SSH Port |
Define which port this sensor uses for the SSH connection:
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Use Port Number |
This setting is only visible if you enable Enter custom port number above. Enter the port number (between 1 and 65535) that this sensor uses for the SSH connection. Enter an integer value. |
SSH Engine |
Select the method that you want to use to access data with this SSH sensor. We strongly recommend that you use the default engine. You can still use the legacy mode for some time to ensure compatibility with your target systems. Choose between:
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Result Handling |
Define what PRTG does with the sensor result:
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Set Limits Checked for ALL Disks
In this section, you can set limits that are valid for all channels and all drives. By entering limits, you can define when the sensor shows the Warning or the Down status, depending on the data provided by all drives that this sensor monitors. If you want to individually define limits for separate channels, use the limit settings in the channel settings.
All limits that you define here are valid in addition to the limits defined in the particular Channel settings. The limits are valid simultaneously, so the first limit that is breached applies.
Setting |
Description |
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Percentage Limit Check |
Enable or disable a limit check for the free space in percentage channels of all drives. By default, percentage limits are enabled with lower warning and lower error limit. Choose between:
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Upper Error Limit |
This setting is only visible if you enable Use the limits of both the sensor and the channel settings above. Specify an upper limit in percent for a Down status. If the free disk space of one of your drives exceeds this percent value, the sensor changes to a Down status. Enter an integer value or leave the field empty.
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Upper Warning Limit |
This setting is only visible if you enable Use the limits of both the sensor and the channel settings above. Specify an upper limit in percent for a Warning status. If the free disk space of one of your drives exceeds this percent value, the sensor changes to a Warning status. Enter an integer value or leave the field empty.
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Lower Warning Limit |
This setting is only visible if you enable Use the limits of both the sensor and the channel settings above. Specify a lower limit in percent for a Warning status. If the free disk space of one of your drives falls below this percent value, the sensor changes to a Warning status. Enter an integer value or leave the field empty.
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Lower Error Limit |
This setting is only visible if you enable Use the limits of both the sensor and the channel settings above. Specify a lower limit in percent for a Down status. If the free disk space of one of your drives falls below this percent value, the sensor changes to a Down status. Enter an integer value or leave the field empty.
|
Size Limit Check |
Enable or disable a limit check for the free bytes channels of all drives:
By default, byte size limits are not enabled for drives. |
Upper Error Limit |
This setting is only visible if you enable Use the limits of both the sensor and the channel settings above. Specify an upper limit. Use the same unit as shown by the free bytes channels of this sensor (by default this is MB). If the free disk space of one of your drives exceeds this bytes value, the sensor changes to a Down status. Enter an integer value or leave the field empty.
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Upper Warning Limit |
This setting is only visible if you enable Use the limits of both the sensor and the channel settings above. Specify an upper limit. Use the same unit as shown by the free bytes channels of this sensor (by default this is MB). If the free disk space of one of your drives exceeds this bytes value, the sensor changes to a Warning status. Enter an integer value or leave the field empty.
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Lower Warning Limit |
This setting is only visible if you enable Use the limits of both the sensor and the channel settings above. Specify a lower limit. Use the same unit as shown by the free bytes channels of this sensor (by default this is MB). If the free disk space of one of your drives falls below this bytes value, the sensor changes to a Warning status. Enter an integer value or leave the field empty.
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Lower Error Limit |
This setting is only visible if you enable Use the limits of both the sensor and the channel settings above. Specify a lower limit. Use the same unit as shown by the free bytes channels of this sensor (by default this is MB). If the free disk space of one of your drives falls below this bytes value, the sensor changes to a Down status. Enter an integer value or leave the field empty.
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Alarm on Missing/Removed Disk |
If a monitored disk is removed or not found, values are set to zero. Select the alarm approach in this case:
|
Setting |
Description |
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Primary Channel |
Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.
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Graph Type |
Define how different channels are shown for this sensor:
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Stack Unit |
This setting is only visible if you enable Stack channels on top of each other as Graph Type. Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so. |
By default, all of the following settings are inherited from objects that are higher in the hierarchy. You should change them centrally in the root group settings if necessary. To change a setting for this object only, click under the corresponding setting name to disable the inheritance. You then see the options described below.
For more information, see section Inheritance of Settings.
Click to interrupt the inheritance.
Setting |
Description |
---|---|
Scanning Interval |
Select a scanning interval from the dropdown list. The scanning interval determines the amount of time that the sensor waits between two scans. Choose from:
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If a Sensor Query Fails |
Select the number of scanning intervals that the sensor has time to reach and to check a device again if a sensor query fails. Depending on the option that you select, the sensor can try to reach and to check a device again several times before the sensor shows the Down status. This can avoid false alarms if the monitored device only has temporary issues. For previous scanning intervals with failed requests, the sensor shows the Warning status. Choose from:
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Schedules, Dependencies, and Maintenance Window
You cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.
Setting |
Description |
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Schedule |
Select a schedule from the list. You can use schedules to monitor during a certain time span (days or hours) every week. Choose from:
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Maintenance Window |
Select if you want to set up a one-time maintenance window. During a maintenance window, monitoring stops for the selected object and all child objects. They show the Paused status instead. Choose between:
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Maintenance Begins |
This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the start date and time of the one-time maintenance window. |
Maintenance Ends |
This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the end date and time of the one-time maintenance window. |
Dependency Type |
Select a dependency type. You can use dependencies to pause monitoring for an object depending on the status of a different object. You can choose from:
|
Dependency |
This setting is only visible if you enable Select a sensor above. Click |
Dependency Delay (Sec.) |
This setting is only visible if you enable Select a sensor above. Define a time span in seconds for the dependency delay. After the master sensor for this dependency returns to the Up status, PRTG additionally delays the monitoring of the dependent objects by the time span you define. This can prevent false alarms, for example, after a server restart or to give systems more time for all services to start. Enter an integer value.
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Click to interrupt the inheritance.
Setting |
Description |
---|---|
User Group Access |
Define the user groups that have access to the sensor. You see a table with user groups and group access rights. The table contains all user groups in your setup. For each user group, you can choose from the following group access rights:
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Click to interrupt the inheritance.
Setting |
Description |
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Channel Unit Types |
For each type of channel, select the unit in which PRTG displays the data. If you define this setting on probe, group, or device level, these settings can be inherited to all sensors underneath. You can set units for the following channel types (if available):
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KNOWLEDGE BASE
How and where does PRTG store its data?
SSH and SFTP Sensors in Unknown Status
How do I set up SSH sensors with my AWS Linux instances?
Why do SSH Disk Free and SNMP Linux Disk Free show different values for my target Linux system?
For more information about sensor settings, see the following sections: