管理分區
查看系統中的分區4種方式
[root@localhost ~]# ls /dev/sd* [來自內存]
[root@localhost ~]# cat /proc/partitions
[root@localhost ~]# lsblk
/dev/sda ?/dev/sda1 ?/dev/sda2 ?/dev/sda3 ?/dev/sda4 ?/dev/sda5
[root@localhost ~]# fdisk -l 看磁盤中的分區表
磁盤中的分區表可能和內存中的分區表是不同步的
parted命令
- parted的操作都是實時生效的，小心使用
- 用法：parted [選項]… [設備 [命令 [參數]…]…]
- parted /dev/sdb ?mklabel gpt|msdos
- parted /dev/sdb ?print
- parted /dev/sdb ?mkpart primary 1 200 （默認M）
- parted /dev/sdb ?rm 1
- parted -l
- mklabel gpt|msdos?用于指定創建的是GPT分區還是MBR分區
- 創建分區
[root@localhost app]# parted /dev/sdb mkpart primary ?1 1000
Information: You may need to update /etc/fstab.
[root@localhost app]# lsblk
NAME ??MAJ:MIN RM ?SIZE RO TYPE MOUNTPOINT
sda ?????8:0 ???0 ?200G ?0 disk
├─sda1 ??8:1 ???0 ???1G ?0 part /boot
├─sda2 ??8:2 ???0 ??50G ?0 part /
├─sda3 ??8:3 ???0 ??20G ?0 part /app
├─sda4 ??8:4 ???0 ???1K ?0 part
└─sda5 ??8:5 ???0 ???2G ?0 part [SWAP]
sdb ?????8:16 ??0 ??20G ?0 disk
└─sdb1 ??8:17 ??0 ?953M ?0 part
GPT分區和MBR分區是互不兼容的，也不存在轉換的問題，一旦設置了GPT分區或者MBR分區，要想裝換只能重新分區
分區工具fdisk和gdisk
- gdisk /dev/sdb 類fdisk 的GPT分區工具
- fdisk -l [-u] [device…] 查看分區
- fdisk /dev/sdb ?管理分區
- 子命令：
- p 分區列表
- t 更改分區類型
- n 創建新分區
- d 刪除分區
- v 校驗分區
- u 轉換單位
- w 保存并退出
- q 不保存并退出
[root@localhost app]# gdisk /dev/sdb
GPT fdisk (gdisk) version 0.8.6
Partition table scan:
MBR: protective
BSD: not present
APM: not present
GPT: present
Found valid GPT with protective MBR; using GPT.
#gdisk的幫助信息
Command (? for help): ?
b back up GPT data to a file ? ? ? ?備份GPT分區
c change a partition’s name ? ? ? 修改分區名
d delete a partition ? ? ? 刪除分區
i show detailed information on a partition
l list known partition types
n add a new partition? ? ? ? 添加一個新分區
o create a new empty GUID partition table (GPT)? ? ? ? 創建一個GUID分區表
p print the partition table? ? ? ? 打印分區表
q quit without saving changes不保存退出
r recovery and transformation options (experts only) ? ? ? 恢復修改的選項
s sort partitions ? ? ? 分區排序
t change a partition’s type code ? ? ? 修改分區類型代碼
v verify disk? ? ? ? 驗證磁盤
w write table to disk and exit寫入磁盤并且退出
x extra functionality (experts only)? ? ? ? 擴展選項
? print this menu? ? ? ? 打印出菜單
Command (? for help):
#把分區表轉換為MBR類型
[root@localhost ~]# parted /dev/sdb mklabel msdos
Warning: The existing disk label on /dev/sdb will be destroyed and all data on this disk will be lost. Do
you want to continue?
Yes/No? yes
Information: You may need to update /etc/fstab.
[root@localhost ~]#
fdisk分區工具的使用
[root@localhost ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Command (m for help): m
Command action
a ??toggle a bootable flag
b ??edit bsd disklabel
c ??toggle the dos compatibility flag 不以dos兼容的模式
d ??delete a partition
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
o ??create a new empty DOS partition table
p ??print the partition table
q ??quit without saving changes
s ??create a new empty Sun disklabel
t ??change a partition’s system id
u ??change display/entry units 以扇區為單位進行顯示（單位為K）
v ??verify the partition table
w ??write table to disk and exit
x ??extra functionality (experts only)
Command (m for help):
在CentOS6中：
[root@localhost ~]# fdisk /dev/sda
WARNING: DOS-compatible mode is deprecated. It’s strongly recommended to
switch off the mode (command ‘c’) and change display units to
sectors (command ‘u’).基于dos兼容模式是棄用。這是強烈推薦關掉模式(命令“c”)和改變顯示單位部門(命令“u”)。也就是用傳統的柱面的方式來劃分去分區，并且要求以整柱面位單位進行劃分，
Command (m for help): p
Disk /dev/sda: 214.7 GB, 214748364800 bytes
255 heads, 63 sectors/track, 26108 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0008cdd6
Device Boot ?????Start ????????End ?????Blocks ??Id ?System
/dev/sda1 ??* ??????????1 ????????131 ????1048576 ??83 ?Linux
Partition 1 does not end on cylinder boundary. 默認以柱面為單位進行劃分，不在整柱面上會提示
/dev/sda2 ????????????131 ???????6658 ???52428800 ??83 ?Linux
/dev/sda3 ???????????6658 ???????9269 ???20971520 ??83 ?Linux
/dev/sda4 ???????????9269 ??????26109 ??135265280 ???5 ?Extended
/dev/sda5 ???????????9269 ???????9530 ????2097152 ??82 ?Linux swap / Solaris
Command (m for help):
CentOS6默認以dos模式柱面為單位
CentOS7默認就是以非dos模式以扇區為單位，默認相當于已經加了c u 了，但也是可以改為以柱面為單位進行顯示，例如打開的時候以柱面為單位進行顯示
[root@localhost ~]# fdisk -h
Usage:
fdisk [options] <disk> ???change partition table
fdisk [options] -l <disk> list partition table(s)
fdisk -s <partition> ?????give partition size(s) in blocks
Options:
-b <size> ????????????sector size (512, 1024, 2048 or 4096)
-c[=<mode>] ??????????compatible mode: ‘dos’ or ‘nondos’ (default)
-h ???????????????????print this help text
-u[=<unit>] ??????????display units: ‘cylinders’ or ‘sectors’ (default)
-v ???????????????????print program version
-C <number> ??????????specify the number of cylinders
-H <number> ??????????specify the number of heads
-S <number> ??????????specify the number of sectors per track
[root@localhost ~]# fdisk -u=cylinders /dev/sda
WARNING: cylinders as display units are deprecated. Use command ‘u’ to
change units to sectors.
Device Boot ?????Start ????????End ?????Blocks ??Id ?System
/dev/sda1 ??* ??????????1 ????????131 ????1048576 ??83 ?Linux
/dev/sda5 ???????????9269 ???????9530 ????2097152 ??82 ?Linux swap / Solaris
注意：注意不要在一個分區中的夾縫中分區，避免分出來的空間過小，或者分區的時候空間過大進行報錯提示
Device Boot ?????Start ????????End ?????Blocks ??Id ?System
/dev/sdc1 ???????????2048 ???????8192 ???????3072+ ?83 ?Linux
/dev/sdc2 ??????????10240 ???62914559 ???31452160 ??83 ?Linux
Last sector, +sectors or +size{K,M,G} (8193-10239, default 10239): +10G
Value out of range.
分區不能調大調小，只能重頭開始分區。例如刪除分區6，分區7會變成分區6。
分區的標識、設備名是不穩定的，帶來的問題就是將來在磁盤上進行分區配置文件的修改，寫/sda5 sda6這樣的名字，萬一刪掉了分區，設備名就變了，數據就找不到了配置文件就會出問題，不推薦寫設備名稱，分區完成后會生成UUID號，是唯一且不變的，建議寫UUID號
在6中創建分區表同步失敗
Command (m for help): n
First sector (148899903-419430399, default 148899903):
Using default value 148899903
Last sector, +sectors or +size{K,M,G} (148899903-148903935, default 148903935):
Using default value 148903935
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@localhost ~]#
需要手動同步分區表
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