Lecture 13 storage management xlanchen@05/20/2005

计算机系•信息处理实验室

Lecture 13 storage management

xlanchen@05/20/2005

xlanchen@05/20/2005 Understanding the Inside of Windows 2000 2计算机系

信息处理实验室

Contents

The Evolution of Windows 2000 Storage

Partitioning

Storage Drivers

Multi-partition Volume Management

The Volume Namespace



Some terms

Disks SectorsPartitions Simple volumesMultipartition volumes



The Evolution of Windows 2000 Storage

MS-DOS

multiple partitions, logical disks

MSDOS could format each partition with a different file system type (FAT12 or FAT16) and assign each partition a different drive letter



Windows NT disk spanning and fault tolerance volumes drawbacks

most disk-configuration changes require a reboot before taking effect the Windows NT 4 registry stores multipartition disk-configuration information for MS-DOS-style partitions an upper limit on the number of possible local and remote volumes



Partitioning

Windows 2000 manages all disks as basic disks unless you manually create dynamic disks or convert existing basic disks (with enough free space) to dynamic disks

Basic disks Disks that rely on the MS-DOS-style partitioning scheme

Dynamic disks support multipartition volumes



Basic Partitioning

System volume For boot files, including the boot loader (Ntldr) and Ntdetect

Boot volume For operating system files such as Ntoskrnl.exe, the core kernel file



MBR

Master boot record (MBR)

MBR code

Partition table

Primary partitions

Extended partition

Active partition





Dynamic Partitioning

Logical Disk Manager (LDM) subsystem LDM maintains one unified database that stores partitioning information for all the dynamic disks on a system—including multipartition-volume configuration



Internal dynamic disk organization



LDM database layout



database table database entry

partition, disk, component, and volume



Storage Drivers

multi(0)disk(0)rdisk(0)partition(1)

Advanced RISC Computing (ARC)



Disk Drivers

Disk storage driver architecture

Storage class driver

Storage port driver

Miniport driver (OEM supply)



Device Naming

Device objects Disk names:

\Device\HarddiskX\DRX Partition object

\Device\Harddisk0\DP(1)0x7e000-0x7ff50c00+2



Basic Disk Management

FtDisk\Winnt\System32\Drivers\Ftdisk.sys

creates disk device objects representing volumes on basic disks manages all basic disk volumes



Dynamic Disk Management

DMDiskManager (Dmdskmgr.dll)

DMAdmin



Database interpretingDMConfig (Winnt\System32\Dmconfig.dll) DMBoot (Dmboot.sys)

DMIO a bus driver creates a device object for each dynamic disk volume

\Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolumeX



DMIO driver device objects



Multipartition Volume Management the partitions that make up a volume can be located on discontiguous partitions or even on different disks Spanned volumes Mirrored volumes Striped volumes RAID-5 volume



Spanned Volumes

A spanned volume is a single logical volume composed of a maximum of 32 free partitions on one or more disks



Striped Volumes

A striped volume is a series of up to 32 partitions, one partition per disk, that combines into a single logical volume.



Logical numbering of physical sectors on a striped volume



Mirrored Volumes

In a mirrored volume, the contents of a partition on one disk are duplicated in an equal-sized partition on another disk



RAID-5 Volumes

A RAID-5 volume is a fault tolerant variant of a regular striped volume.

striped volume with parity

Fault tolerance is achieved by reserving the equivalent of one disk for storing parity for each stripe



the parity for stripe 1 the parity for stripe 2



Volume I/O Operations Related components

FSD

volume managers & volume managers

I/O manager



DMIO I/O operations



The Volume Namespace

The Mount Manager

Mount Points

Volume Mounting



The Mount Manager

A new driver in 2K, Mountmgr.sys drive letters dynamic disk volumes & basic disk volumesHKLM\SYSTEM\MountedDevices

\??\Volume{X} (where X is a GUID)??\C:

Every volume has a volume name entry, but a volume doesn't necessarily have an assigned drive letter.



Example



Mount Points

A new mechanism to 2Klet you link volumes through directories on NTFS volumes, which makes volumes with no drive-letter assignment accessible important technology: reparse point

Mount points are reparse points that store a volume name ( \??\Volume{X}) as the reparse data



Volume Mounting

Documents

Lecture 13 storage management xlanchen@05/20/2005