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Disk partitioning is the creation of one or more regions on a hard disk or other secondary storage, so that an operating system can manage information in each region separately. Partitioning is typically the first step of preparing a newly manufactured disk, before any files or directories have been created. The disk stores the information about the partitions' locations and sizes in an area known as the partition table that the operating system reads before any other part of the disk. Each partition then appears in the operating system as a distinct "logical" disk that uses part of the actual disk. System administrators use a program called a partition editor to create, resize, delete, and manipulate the partitions. == Benefits of multiple partitions == Creating more than one partition has the following advantages: * Separation of the operating system (OS) and program files from user files. This allows image backups (or clones) to be made of only the operating system and installed software. * Having a separate area for operating system virtual memory swapping/paging. * Keeping frequently used programs and data near each other. * Having cache and log files separate from other files. These can change size dynamically and rapidly, potentially making a file system full. * Use of multi-boot setups, which allow users to have more than one operating system on a single computer. For example, one could install Linux, BSD, Mac OS X, Microsoft Windows or other operating systems on different partitions of the same HDD and have a choice of booting into any compatible operating system at power-up. * Protecting or isolating files, to make it easier to recover a corrupted file system or operating system installation. If one partition is corrupted, other file systems may not be affected. * Raising overall computer performance on systems where smaller file systems are more efficient. For instance, large HDDs with only one NTFS file system typically have a very large sequentially accessed Master File Table (MFT) and it generally takes more time to read this MFT than the smaller MFTs of smaller partitions. * "Short stroking", which aims to minimize performance-eating head repositioning delays by reducing the number of tracks used per HDD. The basic idea is that you make one partition approx. 20–25% of the total size of the drive. This partition is expected to: occupy the outer tracks of the HDD, and offer more than double the throughput — less than half the access time. If you limit capacity with short stroking, the minimum throughput stays much closer to the maximum. This technique, however, is not related to creating multiple partitions, but generally just creating a partition less than the disk size. * * For example, a 1 TB disk may have an access time of 12 ms at 200 IOPS (at a limited (queue depth )) with an average throughput of 100 MB/s. When it is partitioned to 100 GB (and the rest left unallocated) access time ''may'' be decreased to 6 ms at 300 IOPS (with a bigger queue depth) with an average throughput of 200 MB/s. * Partitioning for significantly less than the full size available when disk space is not needed can reduce the time for diagnostic tools such as checkdisk to run or for full image backups to run. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Disk partitioning」の詳細全文を読む スポンサード リンク
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