怎样给centos系统扩展磁盘分区的实现方法

问题/故障/场景/需求

eve-ng的虚拟机ova的硬盘只有38g，需要增加空间，在vmware直接扩展硬盘后，重启系统，使用fdisk -l可以看到硬盘扩大了，但文件系统并没有扩大，还需要将这些新增的空间扩展分配到某个文件系统才行。下面记录了整个扩展过程

解决方法/步骤

在vm里扩大磁盘到250g重启系统后，查看当前的文件系统的情况

root@eve-ng:~# df -h
filesystem          size used avail use% mounted on
udev             7.9g   0 7.9g  0% /dev
tmpfs             1.6g  19m 1.6g  2% /run
/dev/mapper/eve--ng--vg-root  38g  13g  23g 36% /
tmpfs             7.9g   0 7.9g  0% /dev/shm
tmpfs             5.0m   0 5.0m  0% /run/lock
tmpfs             7.9g   0 7.9g  0% /sys/fs/cgroup
/dev/sda1           472m  83m 365m 19% /boot

root@eve-ng:~# fdisk -l
...省略部分内容
disk /dev/sda: 250 gib, 268435456000 bytes, 524288000 sectors  //可以看到已经有250g了
units: sectors of 1 * 512 = 512 bytes
sector size (logical/physical): 512 bytes / 512 bytes
i/o size (minimum/optimal): 512 bytes / 512 bytes
disklabel type: dos
disk identifier: 0x3e3ca055

device   boot  start   end sectors size id type
/dev/sda1 *    2048  999423  997376 487m 83 linux
/dev/sda2    1001470 83884031 82882562 39.5g 5 extended
/dev/sda5    1001472 83884031 82882560 39.5g 8e linux lvm

disk /dev/mapper/eve--ng--vg-root: 38.6 gib, 41406169088 bytes, 80871424 sectors
units: sectors of 1 * 512 = 512 bytes
sector size (logical/physical): 512 bytes / 512 bytes
i/o size (minimum/optimal): 512 bytes / 512 bytes

disk /dev/mapper/eve--ng--vg-swap_1: 980 mib, 1027604480 bytes, 2007040 sectors
units: sectors of 1 * 512 = 512 bytes
sector size (logical/physical): 512 bytes / 512 bytes
i/o size (minimum/optimal): 512 bytes / 512 bytes

//下面执行分区
root@eve-ng:~# fdisk /dev/sda

welcome to fdisk (util-linux 2.27.1).
changes will remain in memory only, until you decide to write them.
be careful before using the write command.

command (m for help): n
partition type
  p  primary (1 primary, 1 extended, 2 free)
  l  logical (numbered from 5)
select (default p): p
partition number (3,4, default 3): 3
first sector (999424-524287999, default 999424): 83884032 //注意，这里是之前分配的最后一块（sda5 end）加一（83884031+1）
last sector, +sectors or +size{k,m,g,t,p} (83884032-524287999, default 524287999): //注意看这是不是最后一块

created a new partition 3 of type 'linux' and of size 210 gib.

command (m for help): t
partition number (1-3,5, default 5): 3 3
partition type (type l to list all types): 8e

changed type of partition 'linux' to 'linux lvm'.

command (m for help): w
the partition table has been altered.
calling ioctl() to re-read partition table.
re-reading the partition table failed.: 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).

root@eve-ng:~# reboot

root@eve-ng:~# pvcreate /dev/sda3
 physical volume "/dev/sda3" successfully created
root@eve-ng:~# vgdisplay
 --- volume group ---
 vg name        eve-ng-vg
 system id
 format        lvm2
 metadata areas    1
 metadata sequence no 3
 vg access       read/write
 vg status       resizable
 max lv        0
 cur lv        2
 open lv        2
 max pv        0
 cur pv        1
 act pv        1
 vg size        39.52 gib
 pe size        4.00 mib
 total pe       10117
 alloc pe / size    10117 / 39.52 gib
 free pe / size    0 / 0
 vg uuid        evwubc-nfsg-dhqa-znxb-u3gv-v782-q8zxki

root@eve-ng:~# vgextend eve-ng-vg /dev/sda3
 volume group "eve-ng-vg" successfully extended
root@eve-ng:~# vgdisplay
 --- volume group ---
 vg name        eve-ng-vg
 system id
 format        lvm2
 metadata areas    2
 metadata sequence no 4
 vg access       read/write
 vg status       resizable
 max lv        0
 cur lv        2
 open lv        2
 max pv        0
 cur pv        2
 act pv        2
 vg size        249.52 gib
 pe size        4.00 mib
 total pe       63877
 alloc pe / size    10117 / 39.52 gib
 free pe / size    53760 / 210.00 gib
 vg uuid        evwubc-nfsg-dhqa-znxb-u3gv-v782-q8zxki

root@eve-ng:~# lvdisplay
 --- logical volume ---
 lv path        /dev/eve-ng-vg/root
 lv name        root
 vg name        eve-ng-vg
 lv uuid        ktupr0-vpqs-rjjv-a1fc-u6gd-u8yn-2wyq53
 lv write access    read/write
 lv creation host, time eve-ng, 2018-03-21 02:25:21 +0200
 lv status       available
 # open         1
 lv size        38.56 gib
 current le       9872
 segments        1
 allocation       inherit
 read ahead sectors   auto
 - currently set to   256
 block device      253:0

//扩展逻辑卷
root@eve-ng:~# lvextend -l +100%free /dev/eve-ng-vg/root
 size of logical volume eve-ng-vg/root changed from 38.56 gib (9872 extents) to 248.56 gib (63632 extents).
 logical volume root successfully resized.

root@eve-ng:~# df -h
filesystem          size used avail use% mounted on
udev             7.9g   0 7.9g  0% /dev
tmpfs             1.6g  19m 1.6g  2% /run
/dev/mapper/eve--ng--vg-root  38g  13g  23g 36% /
tmpfs             7.9g   0 7.9g  0% /dev/shm
tmpfs             5.0m   0 5.0m  0% /run/lock
tmpfs             7.9g   0 7.9g  0% /sys/fs/cgroup
/dev/sda1           472m  83m 365m 19% /boot

//在线扩容,要先查看当前的文件系统的类型，可以通过cat /etc/fstab来查看
root@eve-ng:~# resize2fs /dev/eve-ng-vg/root
resize2fs 1.42.13 (17-may-2015)
filesystem at /dev/eve-ng-vg/root is mounted on /; on-line resizing required
old_desc_blocks = 3, new_desc_blocks = 16
the filesystem on /dev/eve-ng-vg/root is now 65159168 (4k) blocks long.

root@eve-ng:~# df -h
filesystem          size used avail use% mounted on
udev             7.9g   0 7.9g  0% /dev
tmpfs             1.6g  19m 1.6g  2% /run
/dev/mapper/eve--ng--vg-root 245g  13g 222g  6% /
tmpfs             7.9g   0 7.9g  0% /dev/shm
tmpfs             5.0m   0 5.0m  0% /run/lock
tmpfs             7.9g   0 7.9g  0% /sys/fs/cgroup
/dev/sda1           472m  83m 365m 19% /boot

参考

在线扩容
使用 resize2fs或xfs_growfs 对挂载目录在线扩容

• resize2fs 针对文件系统ext2 ext3 ext4
• xfs_growfs 针对文件系统xfs
  

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。