GPT简单描述、分区、脚本、lvm练习

1、描述GPT是什么，应该怎么使用。

GUID磁盘分区表（GUID Partition Table，缩写：GPT）其含义为“全局唯一标识磁盘分区表”，是一个实体硬盘的分区表的结构布局的标准。

parted命令

     [root@localhost ~]#  parted
      GNU Parted 3.1
      Using /dev/sda
      Welcome to GNU Parted! Type 'help' to view a list of commands.
      (parted) help                                                             
      align-check TYPE N                        check partition N for TYPE(min|opt) alignment
      help [COMMAND]                           print general help, or help on COMMAND
      mklabel,mktable LABEL-TYPE               设定使用的分区类型, 如果要用MBR分区，输入msdos即可
      mkpart PART-TYPE [FS-TYPE] START END     添加一个分区
      name NUMBER NAME                         name partition NUMBER as NAME
      print [devices|free|list,all|NUMBER]     display the partition table, available devices, free
            space, all found partitions, or a particular partition
      quit                                     exit program
      rescue START END                         rescue a lost partition near START and END
      resizepart NUMBER END                    resize partition NUMBER
      rm NUMBER                                delete partition NUMBER
      select DEVICE                            选择你要操作的设备
      disk_set FLAG STATE                      change the FLAG on selected device
      disk_toggle [FLAG]                       toggle the state of FLAG on selected device
      set NUMBER FLAG STATE                    change the FLAG on partition NUMBER
      toggle [NUMBER [FLAG]]                   toggle the state of FLAG on partition NUMBER
      unit UNIT                                set the default unit to UNIT
      version                                  display the version number and copyright information of
            GNU Parted
    (parted)

[root@localhost ~]# parted /dev/sdb
GNU Parted 3.1
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mktable gpt
(parted) print                                                            
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 21.5GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt 
(parted) mkpart        
Partition name?  []? part1                                                
File system type?  [ext2]? ext4                                           
Start? 0                                                                  
End? 25%                                                                  
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? I
(parted) print                                                            
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 21.5GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 

Number  Start   End     Size    File system  Name   Flags
 1      17.4kB  5369MB  5369MB               part1

(parted) unit GB                                                          
(parted) print                                                          
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdb: 21.5GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 

Number  Start   End     Size    File system  Name   Flags
 1      0.00GB  5.37GB  5.37GB               part1

(parted)

2、创建一个10G的分区，并格式化为ext4文件系统。要求：

(1)block大小为2048，预留空间20%，卷标为MYDATA。
(2)挂载至/mydata目录，要求挂载时禁止程序自动运行，且不更新文件的访问时间戳。
(3)可开机自动挂载。

[root@localhost ~]# mke2fs -t ext4 -b 2048 -m 20 -L MYDATA /dev/sda3
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=MYDATA
OS type: Linux
Block size=2048 (log=1)
Fragment size=2048 (log=1)
Stride=0 blocks, Stripe width=0 blocks
655360 inodes, 5242880 blocks
1048576 blocks (20.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=273678336
320 block groups
16384 blocks per group, 16384 fragments per group
2048 inodes per group
Superblock backups stored on blocks: 
    16384, 49152, 81920, 114688, 147456, 409600, 442368, 802816, 1327104, 
    2048000, 3981312

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done   

[root@localhost ~]# cat /proc/partitions 
major minor  #blocks  name

   8        0  125829120 sda
   8        1     524288 sda1
   8        2  106961920 sda2
   8        3   10485760 sda3
   8        4          1 sda4
   8        5     524288 sda5
   8        6     131072 sda6
   8       16   20971520 sdb
  11        0    4481024 sr0
 253        0   52428800 dm-0
 253        1    2097152 dm-1
 253        2   52428800 dm-2


[root@localhost ~]#  mount -o noexec,noatime /dev/sda3 /mydata/

/dev/sda3 /mydata ext4 rw,seclabel,noexec,noatime,data=ordered 0 0

[root@localhost ~]# vim /etc/fstab

/dev/sda3 /mydata                               ext4    defaults        0 0

3、创建一个大小为1G的swap分区，并启用。

[root@localhost ~]# mkswap /dev/sdb1
Setting up swapspace version 1, size = 1048572 KiB
no label, UUID=386dac56-52ae-4fb9-87b8-a2598204fcca
[root@localhost ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:            972         104         673           7         194         682
Swap:          2047           0        2047
[root@localhost ~]# swapon /dev/sdb1
[root@localhost ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:            972         105         672           7         194         681
Swap:          3071           0        3071

4、编写脚本计算/etc/passwd文件中第10个用户和第20个用户的id号之和。

#!/bin/bash
#
id1=$(head -10 /etc/passwd | tail -1 | cut -d: -f3)
id2=$(head -20 /etc/passwd | tail -1 | cut -d: -f3)
sum=$[$id1+$id2]
echo $sum

5、将当前主机名保存至hostName变量中，主机名如果为空，或者为localhost.localdomain则将设置为www.magedu.com

#!/bin/bash
hostName=$(hostname)
[ -z "$hostName " -o "$hostName" == "localhost.localdomain" -o "$hostName"=="localhost" ] && hostname www.magedu.com

6、编写脚本，通过命令行参数传入一个用户名，判断id好是偶数还是奇数。

#!/bin/bash
#
read -p "Input username: " username

user_id=$(grep "^$username\>" /etc/passwd | cut -d: -f3)
#echo $1, $user_id
let user_id%=2
#echo $user_id

if [ $user_id -eq 0 ]; then
    echo "oushu"
else
    echo "jishu"
fi

7、lvm基本引用以及扩展缩减实现。

pv管理工具：
pvs: 简要pv信息显示
pvdisplay: 显示pv的详细信息

pvcreate /dev/DEVICE: 创建pv

vg管理工具：
vgs
vgdisplay

vgcreate [ -s #[bBsSkKmMgGtTpPeE]] VolumeGroupName PhysicalDevicePath [ PhysicalDevicePath... ]
vdextend VolumeGroupName PhysicalDevicePath [ PhysicalDevicePath... ]
vgreduce VolumeGroupName PhysicalDevicePath [ PhysicalDevicePath... ]
先做pvremove

vgremove

lv管理工具：
lvs
lvdisplay

lvcreate -L #[mMgGtT] -n NAME VolumeGroup

lvremove /dev/VG_NAME/LV_NAME

扩展逻辑卷：
# lvextend -L [+]#[mMgGtT] /dev/VG_NAME_LVNAME
# resize2fs /dev/VG_NAME/LV_NAME

缩减逻辑卷：
# umount /dev/VG_NAME/LV_NAME
# e2fsck -f /dev/VG_NAME/LV_NAME
# resuze2fs /dev/VG_NAME/LV_NAME #[mMgGtT]
# lvreduce -L [-]#[mMgGtT] /dev/VG_NAME/LV_NAME
# mount

快照：snapshot
lvcreate -L #[mMgGtT] -p r -s -n snapshot_lv_name original_lv_name