On Monday 26 March 2007 14:14, you wrote: > On Sat, Mar 24, 2007 at 09:51:04PM +0200, Tzahi Fadida wrote: > > I am reading from LDD3 and in the block device chapter there is a talk > > about KERNEL_SECTOR_SIZE which is supposed to be 512bytes. > > The problem is the terminology. A sector is a very big thing, i.e.: > > in a floppy you have 18 sectors, 2 heads, 80 cylinders and a block size > > of 512bytes. The size of a sector (which is a slice) is 80 * 512 bytes. > > http://en.wikipedia.org/wiki/Cylinder-head-sector > > I am sure this is not what they meant in the kernel. > > I.e., i think they meant block size. > > A sector is the smallest addressable entity on a disk. Almost all hard > drives have 512 byte sectors, though SCSI drives can be reformated with > a different sector size (512 to up to 524 bytes IIRC). Hard drives with > 1k sector sizes will become available in the near future. As far as i know, the sector is not the smallest addressable entity on a disk, in fact it is quite a huge thing. A sector includes all blocks on the radius of a one side of a platter. This is why it is confusing that they claim that a sector is 512 bytes. A block is the smallest entity and it is indeed on most drives 512 bytes. See here for a description of a sector: http://en.wikipedia.org/wiki/Cylinder-head-sector -- Regards, Tzahi. -- Tzahi Fadida Blog: http://tzahi.blogsite.org | Home Site: http://tzahi.webhop.info WARNING TO SPAMMERS: see at http://members.lycos.co.uk/my2nis/spamwarning.html -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
