Fdisk-l display details

Fdisk-l display details

Root@www.bkjia.com ~ # Fdisk-l
Disk/dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065*512 = 8225280 bytes
Sector size (logical/physical): 512 bytes/512 bytes
I/O size (minimum/optimal): 512 bytes/512 bytes
Disk identifier: 0x00044938
Device Boot Start End Blocks Id System
/Dev/sda1*1 638 5120000 83 Linux
Partition 1 does not end on cylinder boundary.
/Dev/sda2 638 893 2048000 83 Linux
Partition 2 does not end on cylinder boundary.
/Dev/sda3 893 1020 1024000 82 Linux swap/Solaris
Partition 3 does not end on cylinder boundary.
/Dev/sda4 1020 1306 2292736 5 Extended
/Dev/sda5 1021 1306 2291712 83 Linux

Resolution:
Disk/dev/sda: 10.7 GB, 10737418240 bytes
The block device name is/dev/sda. The size of this device is 10.7 GB. This number is not very accurate. My system is 10 GB, and 10737418240 bytes. This is the size after being converted to a node, that is: 10737418240/1024/1024/1024 = 10 GB (Note: bytes = B, indicating "Byte", bit = B, indicating "bit ")
255 heads, 63 sectors/track, 1305 cylinders
255 heads: indicates that the number of magnetic heads is 255
63 sectors/track: 63 sectors on each track
1305 cylinders: indicates a total of 1305 cylinders. The cylinders are the smallest units of the partition.
Units = cylinders of 16065*512 = 8225280 bytes

16065 = 255*63 because each head is in the same cylinder, 63 indicates the number of sectors on each track. The product of these two numbers indicates the number of sectors on one cylinder; therefore, 16065*512 indicates that the size of a cylindrical disk is 8225280 bytes.
Sector size (logical/physical): 512 bytes/512 bytes
The size of a slice is 512 bytes.

Conclusion: The size of a disk is equal to the size of a cylindrical disk * Total Number of cylindrical disks = number of magnetic heads * number of sectors on each track * size of one sector * Total Number of cylindrical Disks

That is, the disk size = 8225280*1305 = 10733990400 bytes = 9.99 GB = 255*63*512*1305
In the above example, we show that our disk has only 1305 cylinders, but the partition information below shows the number of 1306 cylinders. don't worry too much. The data displayed in linux is not very accurate.

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