This is the number of rings. The same track on each platter/surface is what makes up one cylinder. A cylinder pierces through all platters.
These are the number of reading platters.
If we multiply the number of rings (cylinders) by the number of platters/surfaces/heads
In example below:
31130*255 = 7938150 tracks
A track is one ring around one platter surface.
Then we can multiply this by 63 sectors/track to get
500103450 sectors
And finally we have 512 bytes/sector so we get:
256052966400 bytes
In easier to understand units, divide by 1024*1024*1024 ( 1 gigabyte ).
~238 GigaBytes
Display in units of cylinders (+/-) is a rounded up or down number…so not exact.
$ sfdisk -l Disk /dev/sda: 31130 cylinders, 255 heads, 63 sectors/track Units: cylinders of 8225280 bytes, blocks of 1024 bytes, counting from 0 Device Boot Start End #cyls #blocks Id System /dev/sda1 * 0+ 1866 1867- 14996646 83 Linux /dev/sda2 1867 26841- 24975- 200607546+ 83 Linux /dev/sda3 27363+ 31130- 3768- 30261248 82 Linux swap / Solaris /dev/sda4 0 - 0 0 0 Empty
Or we can get exact values by using units of sectors with:
$ sfdisk -l -u S Disk /dev/sda: 31130 cylinders, 255 heads, 63 sectors/track Units: sectors of 512 bytes, counting from 0 Device Boot Start End #sectors Id System /dev/sda1 * 63 29993354 29993292 83 Linux /dev/sda2 29993355 431208447 401215093 83 Linux /dev/sda3 439595008 500117503 60522496 82 Linux swap / Solaris /dev/sda4 0 - 0 0 Empty
Start parted with device you want to work with:
parted /dev/sda
Show details of device:
Remove the third partition
rm 3
If you want to shrink an ext4 partition other than root, you can boot into single user mode by appending an
-s
to the end of the kernal boot up parameters.