fdisk与parted分区

　　　　我所接触的linux分区分为两种，一种是使用fdisk分区，另外一种是parted分区。前者是针对mbr模式分区的，后者是针对gpt模式分区的

　　　　fdisk分区：　　　　

fdisk -l  ---->查看磁盘信息
fdisk  /dev/sdc  --->选择需要操作的磁盘（eg:/dev/sdc）

a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition                         ---->删除一个分区
g create a new empty gpt partition table
g create an irix (sgi) partition table
l list known partition types
m print this menu
n add a new partition                　　　　　---->创建一个新分区
o create a new empty dos partition table    
p print the partition table                  
q quit without saving changes                ---->退出分区操作
s create a new empty sun disklabel
t change a partition's system id             ---->分区id (逻辑分区为8e)
u change display/entry units
v verify the partition table
w write table to disk and exit               ---->保存分区操作
x extra functionality (experts only)               

 1 创建分区示例：
 2 command (m for help): n
 3 partition type:
 4    p   primary (0 primary, 0 extended, 4 free)
 5    e   extended
 6 select (default p): p
 7 partition number (1-4, default 1): 1
 8 first sector (2048-4194303, default 2048):
 9 using default value 2048
10 last sector, +sectors or +size{k,m,g} (2048-4194303, default 4194303):
11 using default value 4194303
12 partition 1 of type linux and of size 2 gib is set
13 
14 command (m for help): t
15 selected partition 1
16 hex code (type l to list all codes): 8e
17 changed type of partition 'linux' to 'linux lvm'

创建及扩展逻辑卷

[root@localhost ~]# pvcreate /dev/sdc1                ---->创建pv
  physical volume "/dev/sdc1" successfully created
[root@localhost ~]# vgextend rhel /dev/sdc1           ---->扩展vg卷组
 volume group "rhel" successfully extended
[root@localhost ~]# vgreduce rhel /dev/sdc1           --->如果不想再加入到已有的vg里面，想自己建一个vg卷组，将刚刚扩展进去的pv给移除出来，
removed "/dev/sdc1" from volume group "rhel"
[root@localhost ~]# vgcreate vg2 /dev/sdc1            --->创建新的vg，并设置vg名为vg2
volume group "vg2" successfully created
[root@localhost ~]# lvextend /dev/rhel/root /dev/sdc1
physical volume "/dev/sdc1" not found in volume group "rhel".  --->没添加进vg组，直接扩展到逻辑卷会报错,如要扩展需，先vgextend到相应的vg组
[root@localhost ~]# pvremove /dev/sdc1                   ---->移除pv
labels on physical volume "/dev/sdc1" successfully wiped
如lvextend加入错入则如下解决

[root@localhost ~]# lvextend /dev/rhel/root /dev/sdc1                         ---->将扩展的/dev/sdc1扩展至/dev/rhe1/root中，随后感觉扩展错误，怎么退出，
  size of logical volume rhel/root changed from 90.46 gib (23158 extents) to 92.46 gib (23669 extents).   --->记住该extents大小，是从23158变为了23669
  logical volume root successfully resized
[root@localhost ~]# lvreduce -l 23158  /dev/rhel/root                        ---->这里是将扩展进去的/dev/sdc1给退出来，-l参数 指定extents大小 ，指定缩减后/dev/rhel/root的大小
  warning: reducing active and open logical volume to 90.46 gib
  this may destroy your data (filesystem etc.)
do you really want to reduce root? [y/n]: y
  size of logical volume rhel/root changed from 92.46 gib (23669 extents) to 90.46 gib (23158 extents).
  logical volume root successfully resized                                   ---->成功，之后可重新扩展

[root@localhost ~]# lvcreate -l +100%free rhel /dev/sdc1 -n lv2                 ---->重新创建一个lv卷，-n参数 指定创建后的卷名字 rhel是卷组 ， 
logical volume "lv2" created.

                parted分区：

[root@localhost ~]# parted
gnu parted 3.1
using /dev/sda
welcome to gnu parted! type 'help' to view a list of commands.
(parted) select /dev/sdc                                                   ---->选择要操作的分区，一定要注意所执行的磁盘
using /dev/sdc
(parted) p                                                                 ---->查看当前分区信息
model: vmware, vmware virtual s (scsi)
disk /dev/sdc: 2147mb
sector size (logical/physical): 512b/512b
partition table: gpt
disk flags:

number  start   end     size    file system  name  flags
 1      1049kb  2146mb  2145mb               p     lvm
(parted) mklabel gpt                                                     ---->磁盘格式化为gpt模式，之前是则不需要格式化
warning: the existing disk label on /dev/sdc will be destroyed and all data on   
this disk will be lost. do you want to continue?
yes/no? yes
(parted) mkpart name 0% 100%                                             ---->name为自定义为该分区取名  0% 100% 是磁盘/dev/sdc的区间作为该分区的大小
(parted) p
model: vmware, vmware virtual s (scsi)
disk /dev/sdc: 2147mb
sector size (logical/physical): 512b/512b
partition table: gpt
disk flags:

number  start   end     size    file system  name  flags
 1      1049kb  2146mb  2145mb               name

(parted) set 1 lvm on                                                   ---->依据分区号1,将分区1设置为逻辑卷
(parted) rm 1                                                           ---->删除分区号为1的分区
(parted) q                                                              ---->退出即保存

磁盘格式化后并挂载

 容量缩减,方式一
[root@localhost ~]# df -ht
filesystem            type      size  used avail use% mounted on
/dev/mapper/rhel-root xfs        93g   15g   78g  16% /
devtmpfs              devtmpfs  904m     0  904m   0% /dev
tmpfs                 tmpfs     914m   80k  914m   1% /dev/shm
tmpfs                 tmpfs     914m  8.9m  905m   1% /run
tmpfs                 tmpfs     914m     0  914m   0% /sys/fs/cgroup
/dev/sda1             xfs       497m  124m  373m  25% /boot
/dev/mapper/rhel-home xfs       7.0g   65m  7.0g   1% /home
[root@localhost ~]# mkfs.ext4 /dev/mapper/rhel-home                      ---->缩减分区大小需要先将格式变为ext4格式，xfs格式不支持通过resize2fs缩减
mke2fs 1.42.9 (28-dec-2013)
filesystem label=
os type: linux
block size=4096 (log=2)
fragment size=4096 (log=2)
stride=0 blocks, stripe width=0 blocks
458752 inodes, 1835008 blocks
91750 blocks (5.00%) reserved for the super user
first data block=0
maximum filesystem blocks=1879048192
56 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

allocating group tables: done
writing inode tables: done
creating journal (32768 blocks): done
writing superblocks and filesystem accounting information: done
[root@localhost ~]# resize2fs /dev/mapper/rhel-home 2g                          ---->重新指定/rhel-home卷的大小，需要加单位，不加单位则默认为block块
resize2fs 1.42.9 (28-dec-2013)
resizing the filesystem on /dev/mapper/rhel-home to 524288 (4k) blocks.
the filesystem on /dev/mapper/rhel-home is now 524288 blocks long.
[root@localhost ~]# lvreduce -l 2g  /dev/rhel/home                             ---->2g与上相同
  warning: reducing active logical volume to 2.00 gib
  this may destroy your data (filesystem etc.)
do you really want to reduce home? [y/n]: y
  size of logical volume rhel/home changed from 7.00 gib (1792 extents) to 2.00 gib (512 extents).
  logical volume home successfully resized
[root@localhost ~]# mount /dev/mapper/rhel-home /home/
[root@localhost ~]# df -h
filesystem             size  used avail use% mounted on
/dev/mapper/rhel-root   93g   15g   78g  16% /
devtmpfs               904m     0  904m   0% /dev
tmpfs                  914m   80k  914m   1% /dev/shm
tmpfs                  914m  8.9m  905m   1% /run
tmpfs                  914m     0  914m   0% /sys/fs/cgroup
/dev/sda1              497m  124m  373m  25% /boot
/dev/mapper/rhel-home  1.9g   21m  1.8g   2% /home

缩减容量:方式二(注：该系统卷root与卷home都为xfs文件系统，与上不同，但该操作与文件系统无关联)
[root@localhost ~]# df -h
filesystem             size  used avail use% mounted on
/dev/mapper/rhel-root   91g   15g   77g  16% /
devtmpfs               904m     0  904m   0% /dev
tmpfs                  914m  276k  914m   1% /dev/shm
tmpfs                  914m  9.1m  905m   1% /run
tmpfs                  914m     0  914m   0% /sys/fs/cgroup
/dev/sda1              497m  124m  373m  25% /boot
/dev/mapper/rhel-home  7.0g   65m  7.0g   1% /home
/dev/sr0               3.7g  3.7g     0 100% /media
[root@localhost ~]# lvreduce -l 88g /dev/rhel/root               ---->对根目录操作一定要谨慎再谨慎
  warning: reducing active and open logical volume to 88.00 gib
  this may destroy your data (filesystem etc.)
do you really want to reduce root? [y/n]: y
  size of logical volume rhel/root changed from 90.46 gib (23158 extents) to 88.00 gib (22528 extents).
  logical volume root successfully resized
[root@localhost ~]# lvextend /dev/rhel/home /dev/sda2 /dev/sdb1 /dev/sd
/dev/sda2  /dev/sdb1
[root@localhost ~]# lvextend /dev/rhel/home /dev/sda2 /dev/sdb1   ---->将释放的空间扩展到home卷下
  no free extents on physical volume "/dev/sda2".
  size of logical volume rhel/home changed from 7.00 gib (1792 extents) to 9.46 gib (2422 extents).
  logical volume home successfully resized
[root@localhost ~]# xfs_growfs /dev/mapper/rhel-home                ---->xfs文件系统扩容，ext4使用resize2fs扩容
meta-data=/dev/mapper/rhel-home  isize=256    agcount=4, agsize=458752 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=0        finobt=0
data     =                       bsize=4096   blocks=1835008, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal               bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 1835008 to 2480128
[root@localhost ~]# df -h
filesystem             size  used avail use% mounted on
/dev/mapper/rhel-root   91g   15g   77g  16% /
devtmpfs               904m     0  904m   0% /dev
tmpfs                  914m  276k  914m   1% /dev/shm
tmpfs                  914m  9.1m  905m   1% /run
tmpfs                  914m     0  914m   0% /sys/fs/cgroup
/dev/sda1              497m  124m  373m  25% /boot
/dev/mapper/rhel-home  9.5g   66m  9.4g   1% /home        ---->这里扩容了2.5g
/dev/sr0               3.7g  3.7g     0 100% /media

添加新卷
[root@localhost ~]# lvcreate -l +100%free rhel /dev/sda2 -n lv2     --->创建新的lv卷
  logical volume "lv2" created.
[root@localhost ~]# mkfs.xfs /dev/mapper/rhel-lv2                   ---->将新的lv2卷格式化为xfs格式
meta-data=/dev/mapper/rhel-lv2   isize=256    agcount=4, agsize=327680 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=0        finobt=0
data     =                       bsize=4096   blocks=1310720, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@localhost ~]# mkdir /lv2                                     ---->创建目录
[root@localhost ~]# mount /dev/mapper/rhel-lv2  /lv2/              ---->挂载    
[root@localhost ~]# df -h
filesystem             size  used avail use% mounted on
/dev/mapper/rhel-root   93g   15g   78g  16% /
devtmpfs               904m     0  904m   0% /dev
tmpfs                  914m   80k  914m   1% /dev/shm
tmpfs                  914m  8.9m  905m   1% /run
tmpfs                  914m     0  914m   0% /sys/fs/cgroup
/dev/sda1              497m  124m  373m  25% /boot
/dev/mapper/rhel-home  2.0g   33m  2.0g   2% /home
/dev/mapper/rhel-lv2   5.0g   33m  5.0g   1% /lv2
扩展容量
[root@localhost ~]#xfs_growfs /dev/mapper/rhel-root                   ---->扩展xfs分区大小，这是扩展到root根下
[root@localhost ~]#resize2fs /dev/mapper/rhel-home 7g                 ---->扩展ext4分区大小。