Lecture 13 storage management

1. Lecture 13 storage management xlanchen@05/20/2005

2. Contents • The Evolution of Windows 2000 Storage • Partitioning • Storage Drivers • Multi-partition Volume Management • The Volume Namespace Understanding the Inside of Windows 2000

3. Some terms • Disks • Sectors • Partitions • Simple volumes • Multipartition volumes Understanding the Inside of Windows 2000

4. 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 Understanding the Inside of Windows 2000

5. 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 Understanding the Inside of Windows 2000

6. 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 Understanding the Inside of Windows 2000

7. 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 Understanding the Inside of Windows 2000

8. MBR • Master boot record (MBR) • MBR code • Partition table • Primary partitions • Extended partition • Active partition Understanding the Inside of Windows 2000

9. Understanding the Inside of Windows 2000

10. 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 Understanding the Inside of Windows 2000

11. Internal dynamic disk organization Understanding the Inside of Windows 2000

12. LDM database layout Understanding the Inside of Windows 2000

13. database table • database entry • partition, disk, component, and volume Understanding the Inside of Windows 2000

14. Storage Drivers • multi(0)disk(0)rdisk(0)partition(1) • Advanced RISC Computing (ARC) Understanding the Inside of Windows 2000

15. Disk Drivers • Disk storage driver architecture • Storage class driver • Storage port driver • Miniport driver (OEM supply) Understanding the Inside of Windows 2000

16. Device Naming • Device objects • Disk names: \Device\HarddiskX\DRX • Partition object \Device\Harddisk0\DP(1)0x7e000-0x7ff50c00+2 Understanding the Inside of Windows 2000

17. Basic Disk Management • FtDisk \Winnt\System32\Drivers\Ftdisk.sys • creates disk device objects representing volumes on basic disks • manages all basic disk volumes Understanding the Inside of Windows 2000

18. Dynamic Disk Management • DMDiskManager (Dmdskmgr.dll) DMAdmin Understanding the Inside of Windows 2000

19. Database interpreting • DMConfig (Winnt\System32\Dmconfig.dll) • DMBoot (Dmboot.sys) • DMIO • a bus driver • creates a device object for each dynamic disk volume • \Device\HarddiskDmVolumes\PhysicalDmVolumes\BlockVolumeX Understanding the Inside of Windows 2000

20. DMIO driver device objects Understanding the Inside of Windows 2000

21. 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 Understanding the Inside of Windows 2000

22. A spanned volume is a single logical volume composed of a maximum of 32 free partitions on one or more disks Spanned Volumes Understanding the Inside of Windows 2000

23. A striped volume is a series of up to 32 partitions, one partition per disk, that combines into a single logical volume. Striped Volumes Understanding the Inside of Windows 2000

24. Logical numbering of physical sectors on a striped volume Understanding the Inside of Windows 2000

25. In a mirrored volume, the contents of a partition on one disk are duplicated in an equal-sized partition on another disk Mirrored Volumes Understanding the Inside of Windows 2000

26. 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 RAID-5 Volumes Understanding the Inside of Windows 2000

27. the parity for stripe 1 the parity for stripe 2 Understanding the Inside of Windows 2000

28. Volume I/O Operations • Related components • FSD • volume managers & volume managers • I/O manager Understanding the Inside of Windows 2000

29. DMIO I/O operations Understanding the Inside of Windows 2000

30. The Volume Namespace • The Mount Manager • Mount Points • Volume Mounting Understanding the Inside of Windows 2000

31. The Mount Manager • A new driver in 2K, Mountmgr.sys • drive letters dynamic disk volumes & basic disk volumes • HKLM\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. Understanding the Inside of Windows 2000

32. Example Understanding the Inside of Windows 2000

33. Mount Points • A new mechanism to 2K • let 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 Understanding the Inside of Windows 2000

34. Volume Mounting Understanding the Inside of Windows 2000