Performing Disk Rescans

This topic will cover the rescan types, how to change automatic rescan settings, and how to do a manual rescan.

Rescan Types

Disk rescans cause virtual disk paths to appear or disappear. Rescans discover new paths or re-acquire paths that were previously lost so that failback can occur. When paths change, event polling is triggered.

Automatic rescans can be event-driven or periodic. Rescans can also be performed manually.

Normal and fault rescan interval settings can be changed in the console. The default setting for Normal Rescan Interval is every 300 seconds. The default setting for Fault Rescan Interval is every 60 seconds.

Automatic rescans are persistent and occur whether or not the console is open.

Automatic Rescan Types

  • Event-driven performs a query on all paths based on the Normal Rescan Interval to determine if an event has occurred. Events only occur for path changes.
    • Event-driven rescan type uses both normal and fault rescan interval settings. The normal rescan interval is used to query for path changes. If an event occurs such as when paths are detected or lost, disk rescans are performed at the Fault Rescan interval until the failure is resolved.
    • This is the default rescan type setting. DataCore highly recommends keeping the default settings unless instructed to change them by DataCore Technical Support
  • Periodic performs rescans based only on the Normal Rescan Interval setting.
    • The Fault Rescan Interval setting is never used for this type.

This setting should not be used unless specifically instructed to do so by DataCore Technical Support.

Changing the Automatic Rescan Settings

Improper rescan settings may cause I/O errors. DataCore highly recommends that administrators do not change the rescan settings unless instructed by DataCore Technical Support.

To change the settings:

  1. In the DataCore MPIO Console tree, right-click on MPIO Management and select Properties.
  2. Open the Rescan tab.

To change the rescan type:

In the Rescan Type area, select the check box for the desired type.

To change the rescan intervals:

  1. Adjust the number of seconds in the appropriate interval box.
  2. Click OK to save the settings.

Performing a Manual Rescan

To perform an immediate manual rescan:

In the DataCore MPIO Console tree, right-click on MPIO Management and select Rescan Disks.