Search results
Results from the WOW.Com Content Network
In logical block addressing, only one number is used to address data, and each linear base address describes a single block. The LBA scheme replaces earlier schemes which exposed the physical details of the storage device to the software of the operating system. Chief among these was the cylinder-head-sector (CHS) scheme, where blocks were addressed by means
[4] [5] It defines new functions within the INT 13h service, all having function numbers greater than 40h, that use 64-bit logical block addressing (LBA), which allows addressing up to 8 ZiB. (An ATA drive can also support 28-bit or 48-bit LBA which allows up to 128 GiB or 128 PiB respectively, assuming a 512-byte sector/block size).
The term fixed-block architecture was created by IBM in 1979 [3] to distinguish this format from its variable-length record format. Each track is divided into fixed-length blocks, consisting of an ID field and a data field. Application programs refer to blocks by relative block number, and cannot address them by cylinder, head and record.
Like MBR, GPT uses logical block addressing (LBA) in place of the historical cylinder-head-sector (CHS) addressing. The protective MBR is stored at LBA 0, and the GPT header is in LBA 1, with a backup GPT header stored at the final LBA. The GPT header has a pointer to the partition table (Partition Entry Array), which is typically at LBA 2 ...
Download QR code; Print/export ... IBM—International Business Machines; ... LBA—Logical Block Addressing; LB—Load Balancer;
The partition type (or partition ID) in a partition's entry in the partition table inside a master boot record (MBR) is a byte value intended to specify the file system the partition contains or to flag special access methods used to access these partitions (e.g. special CHS mappings, LBA access, logical mapped geometries, special driver access, hidden partitions, secured or encrypted file ...
Devices may encompass multiple logical units, which are addressed by logical unit number (LUN). Simple devices have just one LUN, more complex devices may have multiple LUNs. A "direct access" (i.e. disk type) storage device consists of a number of logical blocks, addressed by Logical Block Address . A typical LBA equates to 512 bytes of storage.
In 1996, support for logical block addressing (LBA) was introduced in Windows 95B and MS-DOS 7.10 (Not to be confused with IBM PC-DOS 7.1) in order to support disks larger than 8 GB. Disk timestamps were also introduced. [2] This also reflected the idea that the MBR is meant to be operating system and file system independent.