Users Guide

Background Array Scan
Verifies and rectifies correctable media errors on mirror, volume, or parity data for virtual disks. Background array scan (BAS)
starts automatically after a virtual disk is created while in the Windows operating system.
Checkpointing
Allows different types of checkpointing to resume at the last point following a restart. After the system restarts, background
checkpointing resumes at its most recent checkpoint.
Three types of checkpointing are available:
● Consistency Check (CC)
● Background Initialization (BGI)
● Rebuild
Consistency check
Consistency check (CC) is a background operation that verifies and corrects the mirror or parity data for fault-tolerant physical
disks. It is recommended that you periodically run a consistency check on the physical disks.
By default, CC corrects mirror or parity inconsistencies. After the data is corrected, the data on the primary physical disk in a
mirror set is assumed to be the correct data and is written to the secondary physical disk mirror set.
The CC operation reports data inconsistencies through an event notification. A CC cannot be user-initiated in the BIOS
configuration utility, accessed using Ctrl + R. However, CC can be initiated using OpenManage Server Administrator Storage
Management. For more information, see the OMSA user’s guide at www.dell.com/openmanagemanuals.
Background Initialization
BGI of a redundant virtual disk creates the parity data that allows the virtual disk to maintain its redundant data and survive a
physical disk failure. Similar to consistency check (CC), BGI helps the controller to identify and correct problems that might
occur with the redundant data at a later time.
CAUTION: Data is lost if a physical disk fails before the completion of a BGI.
BGI allows a redundant virtual disk to be used immediately.
NOTE:
Although a BGI is software-initiated at the BIOS Configuration Utility (<Ctrl><R>), the PERC S130 drivers must
be loaded before the BGI runs.
Automatic virtual disk rebuild
Rebuilds a redundant virtual disk automatically when a failure is detected if a hot spare is assigned for this capability.
Virtual disk cache policies
The PERC S130 uses part of system memory for cache. It supports the following cache options:
● Read Ahead/Write Back
● No Read Ahead/Write Back
● Read Ahead/Write Through
● No Read Ahead/Write Through
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Virtual Disks