Users Guide

Disk initialization
For physical disks, initialization writes metadata to the physical disk so that the controller can use the physical disk.
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
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 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 operation.
BGI allows a redundant virtual disk to be used immediately.
NOTE:
Although a BGI is software-initiated from within the BIOS Configuration Utility (accessible through Ctrl + R), the
PERC S140 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
NOTE: Configuring virtual disk cache policies on NVMe PCIe SSD is not supported.
The PERC S140 uses part of system memory for cache. It supports the following cache options:
● Read Ahead/Write Back
● No Read Ahead/Write Back
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Virtual Disks