<p class="glsbody" style="margin-top:1pt;">is a partition from which an x86-based computer starts up. The active partition must be a primary partition on a basic disk. If you use Windows exclusively, the active partition can be the same as the system volume. In the DOS partitioning scheme, only primary partitions can be active due to limitations of the standard bootstrap.<p>
<p class="glsbody" style="margin-top:1pt;">The term backup originates from the time when the best way to protect valuable information was to store it in form of archives on external media. It's become now a general notion to mean making duplications of data for protection purposes.<p>
<p class="glsbody" style="margin-top:1pt;">is created by adding a special bootable section when backing up the data to CD/DVDs. Thus you will be able to restore the data from these archives without having to run the program, but by simply booting from these CD/DVDs.<p>
<p class="glsbody" style="margin-top:1pt;">is the smallest amount of disk space that can be allocated to hold a file. All file systems used by Windows organize hard disks based on clusters, which consist of one or more contiguous sectors. The smaller the cluster size, the more efficiently a disk stores information. If no cluster size is specified during formatting, Windows picks defaults based on the size of the volume. These defaults are selected to reduce the amount of space that is lost and the amount of fragmentation on the volume. A cluster is also called an allocation unit.<p>
<p class="glsbody" style="margin-top:1pt;">is a partition type you create only on a basic MBR (Master Boot Record) disk. Extended partition is used if you want to create more than four volumes on a disk, since it may contain multiple logical drives.<p>
<p class="glsbody" style="margin-bottom:1pt;"><a name="bm_F"></a><nobr><b>File System Metadata</b></nobr></p>
<p class="glsbody" style="margin-top:1pt;">The servicing structures of a file system, which contain information about allocating files and directories, security information etc, are named the file system metadata. It is invisible for users and regular applications because its accidental modification usually makes a partition unusable.<p>
<p class="glsbody" style="margin-bottom:1pt;"><a name="bm_H"></a><nobr><b>Hard Disk Geometry</b></nobr></p>
<p class="glsbody" style="margin-top:1pt;">Traditionally, the usable space of a hard disk is logically divided into cylinders, cylinders are divided into tracks (or heads), and tracks are divided into sectors. The triad of values [Sectors-per-Track], [Tracks-per-Cylinder], [Amount-of-Cylinders] is usually named the Hard Disk Geometry or C/H/S geometry. Tracks and cylinders are enumerated from \"0\", while sectors are enumerated from \"1\". These disk parameters play an essential role in the DOS Partitioning scheme. Modern hardware uses an advanced scheme for the linear addressing of sectors, which assumes that all on-disk sectors are continuously enumerated from \"0\". To allow backward compatibility with older standards, modern hard disks can additionally emulate the C/H/S geometry.<p>
<p class="glsbody" style="margin-top:1pt;">The concept of a \"hidden\" partition was introduced in the IBM OS/2 Boot Manager. By default, an operating system does not mount a hidden partition, thus preventing access to its contents. A method of hiding a partition consists in changing the partition ID value saved in the Partition Table. This is achieved by XOR-ing the partition ID with a 0x10 hexadecimal value.<p>
<p class="glsbody" style="margin-top:1pt;">is the 0th sector of the disk. MBR (Master Boot Record) contains important information about the disk layout: - The used partitioning scheme; - The starting records of the Partition Table; - The standard bootstrap code (or the initial code of boot managers, disk overlay software or boot viruses). Generally, the 0th sector is used for similar purposes in all existing partitioning schemes. The MBR capacity is not sufficient to contain sophisticated boot programs. That's why the on-boot software is allowed to use the entire 0th track of the disk. For example, boot managing utilities such as LILO, GRUB and Paragon Boot Manager are located in the 0th track.<p>
<p class="glsbody" style="margin-top:1pt;">Master File Table is a relational database that consists of rows of file records and columns of file attributes. It contains at least one entry for every file on an NTFS volume, including the MFT itself. MFT is similar to a FAT table in a FAT file system.<p>
<p class="glsbody" style="margin-top:1pt;">or File system ID is a file system identifier that is placed in the partition. It is used to quickly detect partitions of supported types. A number of operating systems completely rely on it to distinguish supported partitions. Partition ID is saved in appropriate entries of the Partition Table and takes only 1 byte of space.<p>
<p class="glsbody" style="margin-top:1pt;">is a set of rules, constraints and format of the on-disk structures to keep information on partitions located on a hard disk. There are known several partitioning schemes. The most popular of them is the so-called DOS partitioning scheme. It was introduced by IBM and Microsoft to use multiple partitions in the disk subsystems on IBM PC compatible computers. Another popular partitioning scheme is the so-called Logical Disks Model (LDM) that originates from the UNIX mainframe systems. Veritas Executive accommodates a simplified version of LDM to the Windows 2000 operating system. Windows 2000 and XP support two quite different partitioning schemes: the old DOS partitioning scheme and the new Dynamic Disk Management (DDM). The problem is that earlier versions of Windows do not support DDM. In addition, most hard disk utilities do not support it as well.<p>
<p class="glsbody" style="margin-top:1pt;">is a CD/DVD disc, a USB flash card or even a floppy disk from which you can boot for maintenance or recovery purposes.<p>
<p class="glsbody" style="margin-top:1pt;">is the top-level directory of a formatted logical drive to include other files and directories. In modern file systems (Ext2/Ext3, NTFS and even FAT32) it does not differ from other directories. This is not the case for old FAT12 and FAT16 file systems.<p>
<p class="glsbody" style="margin-top:1pt;">In the DOS partitioning scheme, every hard disk and every partition has a 32-bit serial number represented by an 8-figure hexadecimal value. It is stored in the MBR and its value is assigned when the MBR sector is initialized by Microsoft standard disk managing tools, such as Windows Disk Administrator and the FDISK utility. In fact, a hard disk's serial number is not important for most operating systems and software. It is known that Windows NT, 2000 and XP store its value in the database of assigned drive letters. A partition's serial number is stored in its boot sector (in FAT16, FAT32 and NFTS file systems). Its value is assigned when the partition is formatted. It does not play an important role for most operating systems and software as well.<p>
<p class="glsbody" style="margin-top:1pt;">or Partition Label is a small textual field (up to 11 characters) that is located in the partition's boot sector. This value is used for notification purposes only. It is detectable by any partitioning tool including the DOS FDISK utility. Modern operating systems save it within a file system, e.g. as a special hidden file. Thus it is able to contain a relatively large amount of text in multiple languages.<p>
