Reclaiming Space of Unused Logical Drives

Identifying Unmapped (Orphans) Logical Drives

Over time, as servers connected to a SAN get decommissioned, administrators find an increasing number of unmapped logical drives that are no longer used by any server. These logical drives, while unused, still occupy disk space in the subsystem. Being able to identify such unmapped logical drives and reclaim the disk space uselessly consumed by these drives will help administrators avoid unnecessary upgrades and extensions of their subsystem.

To list the logical drives in a subsystem that are not mapped to any server and therefore safe to remove, right-click the disk subsystem icon > KM Commands >Reporting> Logical Drives Mapping Table... .

Whether a logical drive is actually mapped or not is also shown in the infobox of each volume instance.

IBOX_LogicalDrive

Logical Drive Properties - Infobox tab

Identifying Unused Logical Drives

When a server is decommissioned or reconfigured, its associated logical drives can stay mapped preventing storage administrator from accurately identifying unused logical drives. Since the KM monitors permanently the traffic on each logical drive, it becomes easy to detect logical drives for which the activity is null.

1.	Create a PATROL Query in the PATROL Console to show the value of the TimeSinceLastActivity parameter of the SEN_I345_LOGICALDRIVE class; In the main menu bar, click Action > New Query…

QUERY_Unused_LogicalDrives

PATROL Query – General Tab

2.	Enter the Query name (example: Unused Logical Drives)

3.	Enter the Query description (optional)

4.	In the Query Results Filter section, select Show Selected Objects and check the Parameters box

5.	In the Additional Filtering, select the Enable Application Class level filtering and the Enable Parameter level filtering options

6.	Open the Application Class tab

QUERY_Unused_LogicalDrives_Class

PATROL Query – Application Class Tab

7.	In the Pattern Matching section, select Like and type SEN_I345_LOGICALDRIVE

8.	Open the Parameter tab

QUERY_Unused_LogicalDrives_Parameter

PATROL Query – Parameter Tab

9.	In the Pattern Matching section, select Like and type TimeSinceLastActivity

10.	Click OK to display a list of the monitored LUNs and their respective number of days since when the KM has not recorded any activity.

The TimeSinceLastActivity parameter is evaluated from the date the KM was initially started.