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

1the Linux system currently supports two dynamic scalable disk management methods:

1Query raid management: this is a way to initialize hard disk management before system installation, and logical disk array management methods such as raid0,raid1,raid5,raid10 are commonly used.

Raid0: at least 1 disk read and write fast without redundancy one disk damaged data is lost raid1: at least 2 disks read and write slow one read and write a backup can lose a disk raid5: at least 3 disks can be sketched fast and a check disk can be used Loss of a disk raid10: at least 4 disk read and write speed, half read and write speed, half backup can lose half of the hard disk raid5 check disk logic diagram:

2, after the system is installed, use the LVM command to manage the disk (slowly less)

2. Hard disk classification:

1. Classify by hard disk structure:

Mechanical hard disk (HDD: slow speed is suitable for large amounts of data storage with low cost

Solid state disk (SSD) read fast SSD (memory) cost is expensive

2. Classified by hard disk interface:

SCSI

SATA

SAS (mainstream)

PCI-E

/ dev is the Linux system, so the hardware device file

/ dev/sda represents the first hard disk

/ dev/sda1 represents the first partition of the first hard disk

/ dev/sda2 represents the first hard disk and the second partition

/ dev/sda3 represents the first hard disk and the third partition

/ dev/sda4 represents the first hard disk and the fourth partition

Note: there are up to 4 primary partitions for a hard drive. Or three primary partitions, and the fourth primary partition is set aside as an extended partition (extend). The name starts with / dev/sda5.

/ dev/sdb represents the second hard drive

/ dev/sdc represents the third hard drive

MBR sector: 512K in total, where the master boot record is located

Fdisk-l to view current hard disk partitions

Df-h to view the mount usage of the current partition

Lsblk displays partitions in a tree structure

Blkid View Partition only represents UUID

/ etc/fstab partition automatically mounts files

3. There are two main disk partition commands:

Fdisk: maximum support for 2T partitions

Parted: supports GPT and is suitable for large capacity partitions

Fidsk Partition Command

Step 1: fdisk / dev/sda

P displays the current partition situation

N create Partition

Primany selects the primary partition

Extended Select extended Partition

D delete partition

W Save Settings

Step 2: mkfs.xfs / dev/sda1

Ext2

Ext3

File system format for ext4 Linux6 series

File system format for xfs Linux7 series

Of course: a hard disk can also be formatted and used without partition, and the whole disk is faster than partition.

Step 3: Mount

Mount / dev/sda1 / mnt mounts the partition in the / mnt directory. When you write data in the / mnt directory, you write the data to / dev/sda1.

Umount / dev/sda1

Umount / mnt unmount mount

Step 4: realize auto-mount partition on boot

1dyne echo 'mount / dev/sda1 / mnt' > > / etc/rc.local

2, write / etc/fstab

Parted: command partition

Parted-l to view the current partition

Step 1: parted / dev/sda partition

Mktable creates disk labels GPT,fdiskz supports MBR

Gpt handwritten gpt

P check the partition situation

Mkpart start Partition

It can be zoned all the time. Parted partition supports 128primary partitions

Step 2: mkfs.xfs / dev/sdb1

Step 3: Mount

Step 4: realize automatic mount on boot

4. Enterprise case:

The java environment does not have enough memory and occupies swap partitions

Free-h view current mem and swap details

The essence of dd if=/dev/zero of=/tmp/200m bs=1M count=200 dd is the command function of creating and copying files

/ dev/zero White Hole continuous content output

/ dev/null black hole continuous inhalation of content

Mkswap / tmp/200 formatted partition

Swapon / tmp/200 activate swap Partition

5. Find large files in the system

1find /-type f-szie + 2G | xargs ls-lh

2find /-type f-size + 2G-exec ls-lh {}\

3,du

6, add a default gateway

Route add default gw xxxx

Route del defalut gw xxxx

Add a route entry

Ip route add 0ap0 via Gateway

Ip route del 0ap0 via Gateway

Add ip to the network card

Ip address add xxxx/24 dev eth0

Ip address add xxxx/24 dev eth2

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