====== MS-SQL Free disk space ======

===== Purpose =====
  * SQL Server files can grow automatically from their originally specified size.
  * When you define a file, you can specify a specific growth increment.
  * Every time the file is filled, it increases its size by the growth increment. 
  * Each file can also have a maximum size specified. If a maximum size is not specified, the file can continue to grow until it has used all available space on the disk.
  * It becomes then crucial to monitor free disk space on which files are stored

**Monitor features include :**
  * Monitoring free disk space on which database files are stored. It can be done on  every SQL Server file type (Data - row -, Log ...) or specific file name
  * Able to alert if free disk space has reached a given threshold expressed in MB or percentage

===== Configuration hints =====
**Surveillance table:** 
  * This is a table of rules that you can use to configure and customize the configuration.
  * Each line of the table will define a rule of monitoring.
  * You can combine multiple rules to cover different cases. 
  * Within a rule, you can configure the **SQL Server file type** you want to monitor, **specific file name(s)** using regular expressions, a **free disk space  threshold** expressed in MB or percentage


**File type**\\
Select the specific SQL server file type you want to monitor , select "All" to monitor free disk space on which all kind of files are stored


**File name:**\\
You can set a file specific rule by setting its name in the File name filter field. Use * to match any file name, or use regular expressions.


**Free disk space:**\\
Use the multi-threshold syntax to set multiple threshold/severity associations: G2W:40 W2M:30 M2C:5 (Green To Warning, Warning To Major, etc...), expressed in MB or percentage  An alarm of the corresponding severity will be sent if free disk space on wich the file is stored is**lower than** threshold.  Set 0 in the field if unused
 
Notice that values retrieved in MB will be rounded 
===== Surveillance table =====

^Parameter^Description^
^Active|Use this field to activate or deactivate a line of configuration.|
^File type|Select the specific SQL Server type file you want to monitor Select "All" so to monitor every type of file|
^File name|A filter to match only a specific SQL Server file name, you can use regular expression, white or black list|
^Free disk space|The threshold for the free disk space You can use the multi threshold syntax (i.e. : G2W:40 W2C:5) . Values can be expressed in MB or Percentage|
^Unit|Represents  the free disk space unit of measure|
^Auto clear|If checked, the alarm will be cleared as soon as the alarm condition is not met anymore.|
^Alarm tag|This field allows to add custom text within the alarm message. %MSG% variable will contain the actual generated message and can be used such as: "my_prefix %MSG% my_suffix". By default, tag will be used as prefix.|
^Alarm|If checked, this line of surveillance will be used for alarm generation.|
^Metric|If checked, this line of surveillance will be used for metric generation.|
^Report|If checked, this line of surveillance will used for showing threshold and severity in the daily report|
===== Examples =====
 
^Active^File type^File name^Free disk space^Unit^Auto clear^Alarm tag^Alarm^Metric^Report^
|true|Data|DBDATA|G2W:30 W2C:5|Percentage|true| |true|true|true|

**Effect** : For this rule, only Data - rows - type files  will be monitored (File Type set to : "Data").
 
All Data type files containing the string "DBDATA" on their file names will be taken into account.
  
A WARNING alarm is sent if free disk space on which each one of those files is 30% or less, a CRITICAL alarm if 5% or less.
===== Generated metrics =====
 
^metricId^metricUnit^metricTarget^metricDescription^
|MSSQL_DATABASE_FREE_DISK_SPACE_MB|MB|[File type] - [File name]|Retrieved free disk space for a given database file,  expressed in MB|