Avago Technologies MegaRAID Fast Path Software - Manual (Page 203)

LSI Corporation Confidential | July 2011 Page 203
MegaRAID SAS Software User Guide Chapter 4: WebBIOS Configuration Utility | Managing Configurations
NOTE: Start a consistency check immediately after the rebuild is complete to ensure
data integrity for the virtual drives. See
Section 4.14.1, Running a Consistency Check for
more information about checking data consistency.
 Scenario #2: If some of the drives in a configuration are removed and re-inserted,
the controller considers the drives to have foreign configurations.
Import or clear the foreign configuration. If you select Import, automatic rebuilds
will occur in redundant virtual drives.
NOTE: Start a consistency check immediately after the rebuild is complete to ensure
data integrity for the virtual drives. See
Section 4.14.1, Running a Consistency Check for
more information about checking data consistency.
 Scenario #3: If all of the drives in a virtual drive are removed, but at different times,
and re-inserted, the controller considers the drives to have foreign configurations.
Import or clear the foreign configuration. If you select Import, all drives that were
pulled before the virtual drive became offline will be imported and then
automatically rebuilt. Automatic rebuilds will occur in redundant virtual drives.
 If the drives in a non-redundant virtual drive are removed, the controller considers
the drives to have foreign configurations.
Import or clear the foreign configuration. No rebuilds occur after the import
operation because there is no redundant data to rebuild the drives with.
4.14.3.2 Importing Foreign
Configurations from Integrated
RAID to MegaRAID The LSI Integrated RAID solution simplifies the configuration options and provides
firmware support in its host controllers. LSI offers two types of Integrated RAID (IR):
Integrated Mirroring (IM) and Integrated Striping (IS).
You can import an IM or IS RAID configuration from an IR system into a MegaRAID
system. The MegaRAID system treats the IR configuration as a foreign configuration.
You can import or clear the IR configuration.
NOTE: For more information about Integrated RAID, refer to the Integrated RAID for SAS
User’s Guide. You can find this document on the LSI website at:
http://www.lsi.com/cm/DownloadSearch.do .
4.14.3.3 Troubleshooting
Information An IR virtual drive can have either 64 MB or 512 MB available for metadata at the end of
the drive. This data is in LSI Data Format (LDF). MegaRAID virtual drives have 512 MB for
metadata at the end of the drive in the Disk Data Format (DDF).
To import an IR virtual drive into MegaRAID, the IR virtual drive must have 512 MB in the
metadata, which is the same amount of mega data as in a MegaRAID virtual drive. If the
IR virtual drive has only 64 MB when you attempt to import it into MegaRAID, the
import will fail because the last 448 MB of your data will be overwritten and the data
lost.