Linux-based Disk Management

Linux-based disk Management

About Disk Management in Linux we should start with the following four aspects to understand and learn the knowledge of Disk Management .

Structure of the 1th disk--hard disk

Parameters of the hard disk

structure: Disk disc, head, motor (mechanical keyboard )

Type: solid-state drives (SSB) and mechanical hard drives

Interface: Early IDE interface, now Sata,scsi,sas

There are capacity, speed, transmission speed, cache and so on.

Hard disk storage Terminology

Head: Head

Track: Tracks

Cylinder: Cylinder surface

SECOTR: Sector 512bytes (bytes)

Partition formatting of the 2nd disk

First, you need to understand why partitioning?

1 Optimizing I/O performance

2 Implementing disk space quotas

3 Improve Repair speed

4 Isolating systems and programs

5 Installing multiple OSes

6 Using different file systems

Next is the partitioning

There are two ways to partition: MBR, GPT

MBR: The early partition standard, which was born in 1982, supports partitions up to 2T and supports a maximum of 4 primary partitions. Typically stored in hard disk 0 track 0 sector 512bytes size space

GPT: Latest partition Standard, supports up to 128 primary partitions, supports up to 8z HDD size

Disk Partitioning Tool

FDISK: MBR partitioning standard supported

Gdisk: Supports GPT partition standard

Parted: Both partition standards support direct partitioning by command

Parted advanced partitioning operations (create, copy, resize, and so on)

Partprobe re-setting the kernel partition table version in memory

Parted

Parted/dev/sdb Mklabel GPT

Change partition for GPT to kill disk data directly

Parted/dev/sdb Mkpart Primary 1 1000

The size of the disk on the real-time effect

-fdisk

Fdisk/dev/device

Interactive directives

n Create a new partition

D Delete Partition

P Display the current partition table

t change the partition type

L LIST the types of all supported partitions

Q Do not save exit

Wq Save exit

Create a partition directly from the command line

Echo-e "n\np\n1\n\n+2g\nw\n |fdisk/dev/sdx mind to sober step-by-step,

-gdisk

Gdisk/dev/device

Interaction instructions and Fdisk are not much different.

FDISK will be gdisk.

-parted

Parted/dev/device Creating partitions interactively

parted [options]/dev/device [cmd] Options ... Create a partition directly from the command line

Parted/dev/sdb Mkpart Primary 1 1G Create a 1G-sized partition with 1 and 1G representing the starting point respectively

Formatting tools

Mkfs. [Type] Universal formatting tool

MKE2FS Ext Series Formatting tools

Mkawap Format swap partition

Common file systems in Linux

ext2 ext3 ext4 xfs btrfs Swap iso9660 NFS ...

Mkfs

-t specifies the file system type, MKFS-T type is equivalent to mkfs.type-l the specified volume label MKFS.XFS/DEV/SDB1 format partition into XFS partition

Mke2fs

Usage: mke2fs [options]/dev/device options:-T Specify the file system type Ext2/ext3/ext4-b Specify the block size 1024/2048/4096-l Specify the volume label-l '      LABEL '-M administrator reserved space-M 5: Reserved 5%-o Enable or disable function modules such as:-O ^has_journal turn off log function-n Create how many inode numbers-I specify how many directly correspond to an inode number Example: Mke2fs-t ext4-b 2048-l ' first '-M 5-o ^has_journal-i 2048/dev/sdb1 tune2fs-l/dev/sdb1 View File system Whether the creation was successful

Three disk quotas

Disk quotas are objects that are directories, and the directory must be mounted to a separate partition. Its main role is to limit the user to create file size and number of files.        Create a process:     ①, re-mount the catalog to enable the Quota function module             Method 1:mount -o remount,usrquota,grpquota /home     # #前提:/home must be mounted separately to a partition            Method 2: Modify/etc/fstab, The feature options are defined as Defaults,usrquota,grpquota, and then re-mount the     ② with remount, close selinux           setenforce 0   do not close selinux, the following creation process will be error     ③ , Initialize database           quotacheck         # #执行该命令, you can create Quota.user and quota.group two database     ④, enable quota function in the/home directory            quotaon /home    ⑤, edit Quotas            edquota username   Adjust file limit size and quantity     ⑥, test           su -  username  switch to the user for quota testing

Soft RAID does not introduce the production of mostly hard raid

Four Logical Volume managers

  Create a logical volume process     # #sdb  SDC is two new hard disk     ①, creating a physical volume pv    (Physical volume)           pvcreate /dev/sd{b,c}  # #可使用pvdisplay查看是否创建成功     ②, create Volume group vg       (volume  Group)               vgcreate -s  16m vg_test /dev/sd{b,c}   # #创建卷组 and add PV to the volume group,-s  specify PE size            # #PE: Create basic unit of LV, PE value should not be too small, otherwise, disk may produce fragmentation, affect disk performance.     ③, creating logical Volumes lv       (logical volume)            lvcreate -l 2g -n lv_test vg_test ## Create a 2G-size logical Volume         ④, create file system            mkfs.xfs /dev/vg_test/lv_test     # #创建xfs文件系统     ⑤, mounting            mount /dev/vg_test/lv_test /mnt/lv_test      Extending logical volumes     lvextend -r -l +3g lv_test      ## Extend the space and file system together       reduce logical volume     ①, un-mount            umount /mnt/lv_test    ②, check file system           e2fsck -f /dev/vg_test/lv_test    ③, shrink file system           resize2fs|xfs_grows lv_test 5G      # #resize2fs针对ext系列文件系统缩减, xfs_grows reduces     ④, reduces space     for XFS file systems       lvreduce -l 5g /dev/vg_test/lvtest # #注意, File system and space reduction sizes must be consistent     &nbspRemove disk/DEV/SDB process     ①, transfer/dev/sdb data            pvmove /dev/sdb    ②, after the data transfer is complete, remove the/DEV/SDB from the disk            vgreduce /dev/sdb    ③, delete pv           pvremove /dev/sdb      Create a snapshot      lvcreate snap_test -l 1g -s -p r /dev/vg_test/lv_test     -L   Specify the snapshot size     -s   specify that the logical volume is snapshot     -p r      Configure this snapshot as read-only

It is recommended that LVM and RAID array disks be used together!

Linux-based Disk Management