|
From: | Chris Johnson |
Subject: | bug#22496: why does the parted math look wrong - Q1 ? |
Date: | Sat, 30 Jan 2016 15:48:44 -0500 |
User-agent: | Mozilla/5.0 (X11; SunOS i86pc; rv:10.0.6esrpre) Gecko/20120731 Thunderbird/10.0.6 |
Hi, I need some education on how parted is doing math. ;-) The drive is 1 TB. # parted /dev/rdsk/c7t1d0p0 GNU Parted 2.3.0 Using /dev/rdsk/c7t1d0p0 Welcome to GNU Parted! Type 'help' to view a list of commands. (parted) unit cyl unit cyl (parted) p p Model: Generic Ide (ide) Disk /dev/rdsk/c7t1d0p0: 121601cyl Sector size (logical/physical): 512B/512B BIOS cylinder,head,sector geometry: 121601,255,63. Each cylinder is 8225kB. Partition Table: gpt Number Start End Size File system Name Flags 1 0cyl 121600cyl 121600cyl zfs 9 121600cyl 121601cyl 1cyl Question 1) Based on the parted value 8225KB per cylinder, I would think that sectors per cylinder could be calculated thus 8225 KB/cyl * 1024 Bytes/KB = 8422400 Bytes/cyl and 8422400 Bytes/cyl / 512 Bytes/sector = 16450 sectors per cylinder However, I would also think that sectors per cylinder could be calculated thus: 255 * 63 = 16065 sectors per cylinder Obviously these numbers do not match. Just for the heck of it, in case when parted says 1 KB it means 1,000 bytes not 1,024 bytes, I did this math. 8225 * 1000 = 8225000 / 512 = 16064.4531 sectors per cylinder which is certainly closer to the value you get from 255 * 63 but it really doesn't make any sense to me to be thinking that we are getting a fractional number of sectors in a given cylinder. Thanks for your insight. |
[Prev in Thread] | Current Thread | [Next in Thread] |