Shulou(Shulou.com)06/02 Report--

Everything in the linux system is a file:

1 the linux file system maps all devices to files, and all files are used as access entries to open read write close with the nature of files.

2 linux device files have two types of block devices: block (access unit block) disk character device: char (access unit "character") keyboard

3 device file: associate a file with the driver of a device, and then communicate with the corresponding hardware device (read, write) for hardware control

Device number:

1 device file: only source data but no data

2 main device number major number identifies the device type

Three times the device number minor number identifies different devices under the same device type.

The device files are all in / dev/dev_file

Hard disk interface type:

1 parallel port IDE theoretical value 133M/s SCSI theoretical value 644M/s

2 serial port SAS 6Gbps STAT3 6Gbps usb 3.0 480M/s

Rpm:rotations per minute (speed)

File naming for hard disk devices:

1 IDE: / dev/hd

2 scsi SATA SAS USB: / dev/sd

3 different devices use different letters to denote amurz

/ dev/sda,/dev/sdb.

4 different partitions of the same device: number

/ dev/sda1

/ dev/sda2

Track: the track above a disk.

1 track: where the tracks on the disk are actually used to store data

2 cylinder: the cylinder above the cylindrical disk

3 cecotr: the cylinder 512 byte above the sector disk

How to partition:

1 divide by cylinder

2 the zero sector of the zero track of the hard disk is reserved, which is called mbr co-512bytes

3 MBR:boot master record

4 446byte is used to store boot loader

5 64byte is used to store partition tables

6 16byte identifies a partition. A disk can only identify four partitions.

7 2byte:55AA four hexadecimal digits if it's 55AA, 550bytes is valid, otherwise it's invalid.

8 if a single hard disk is larger than 2t, the current mbr technology cannot recognize the disk space beyond 2t.

Gpt and uefi can be used after 2t.

Linux's partition management tools:

1 fdisk parted sfdisk

2 fidsk can only manage 15 partitions for a hard disk

3 fdisk-l [- u] device

4 if you want to perform a partition, use fdisk device directly

5 introduction to the usage of the partition tool fdisk

Introduction to fdisk command parameters

P, print partition table.

N. Create a new partition.

D. Delete a partition.

Q. Exit is not saved.

W. Write the partition to the partition table, save and exit.

L, showing all partition codes

T, adjust the partition type

6 check whether the kernel has recognized the new partition

Cat / proc/partations

7 manually notify the system to read the new partition

Partx-a / dev/sda

Partx-a-n 4-6 / dev/sda

8 another way

Kpartx-a / dev/device

-f force

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.