jonas@lkbpyr.UUCP (Jonas Heyman) (09/15/89)
Hello, I was wondering how unix disks works, how does a disk look like when it has: 823 cyl 19 heads 9 sectors Could anybody tell me how all this fits together: cylinder,heads,sectors, block,track. And explain each of them separate. Sincerely Jonas -- jonas@lkbpyr.lkb.se
cpcahil@virtech.UUCP (Conor P. Cahill) (09/15/89)
In article <100@lkbpyr.UUCP>, jonas@lkbpyr.UUCP (Jonas Heyman) writes: > Hello, > > Could anybody tell me how all this fits together: cylinder,heads,sectors, > block,track. The disk is composed of several plates (platters) that contain data. Each of these plates will usually (if not always) have two sides. A "head" is required to read and/or write each side of each plate. The plates are all the same size and rotate around the same core just slightly separated (the read/write heads must fit between each plate). A track is a full circle of data on a single side of a plate. The side will have multiple cocentric tracks each of which are broken up into the same number of sections (sectors). Since the plates sit atop each other in the drive, the collection of the same track from each side of each plate in the disk is a cylinder. So each disk is composed of #_of_heads surfaces each cylinder is composed of #_of_heads tracks. each track is composed of #_of_sectors sectors. each sector is usually composed of 512 bytes. A "block" is usually a logical issue not directly associated with the low level format of the disk (other that the fact that it is normally equal to, or a multiple of the size of a sector. -- +-----------------------------------------------------------------------+ | Conor P. Cahill uunet!virtech!cpcahil 703-430-9247 ! | Virtual Technologies Inc., P. O. Box 876, Sterling, VA 22170 | +-----------------------------------------------------------------------+