Dell Background Initialization and RAID Initialization Processes for Virtual Disks

NOTE: There is a delay to I/O operations when a configured disk is being spun up.

Types Of Virtual Disk Initialization

You can initialize the virtual disks as described in the following sections:

CAUTION: The initializing virtual disks task erases the files and file systems while keeping the virtual disk configuration intact. Initializing a virtual disk destroys all data on the virtual disk.

NOTE: The initialization operations mentioned here are not applicable for  Non-RAID disks.

Background Initialization Of Virtual Disks

Background Initialization (BGI) is an automated process that writes the parity or mirror data on newly created virtual disks. BGI does not run on RAID 0 virtual disks. You can control the BGI rate in the Dell OpenManage storage management application. Any change in the BGI rate does not take effect until the next BGI run.

NOTE: You cannot disable BGI permanently. If you cancel BGI, it automatically restarts within five minutes. For information on stopping BGI, see the topic Stopping Background Initialization.

NOTE: Unlike full or fast initialization of virtual disks, background initialization does not clear data from the physical disks.

NOTE: CC/BGI typically causes some loss in performance until the operation completes.

Consistency Check (CC) and BGI perform similar functions in that they both correct parity errors. However, CC reports data inconsistencies through an event notification, but BGI does not. You can start CC manually, but not BGI.

Full Initialization Of Virtual Disks

Performing a full initialization on a virtual disk overwrites all blocks and destroys any data that previously existed on the virtual disk. Full initialization of a virtual disk eliminates the need for the virtual disk to undergo a BGI. Full initialization can be performed after the creation of a virtual disk.

During full initialization, the host is not able to access the virtual disk. You can start a full initialization on a virtual disk by using the Slow Initialize option in the Dell OpenManage storage management application. For more information on using the BIOS Configuration Utility to perform a full initialization, see the topic Initializing Virtual Disks.

NOTE: If the system reboots during a full initialization, the operation aborts and a BGI begins on the virtual disk.

Fast Initialization Of Virtual Disks

A fast initialization on a virtual disk overwrites the first and last 8 MB of the virtual disk, clearing any boot records or partition information. The operation takes only 2–3 seconds to complete and is recommended when you are recreating virtual disks. To perform a fast initialization using the BIOS Configuration Utility, see the topic Initializing Virtual Disks

Consistency Checks

Consistency Check (CC) is a background operation that verifies and corrects the mirror or parity data for fault tolerant virtual disks. It is recommended that you periodically run a consistency check on virtual disks.

You can manually start a CC using the BIOS Configuration Utility or the Dell OpenManage storage management application. You can schedule CC to run on virtual disks using a Dell OpenManage storage management application. To start a CC using the BIOS Configuration Utility, see the topic Checking Data Consistency.

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