分区扩容命令_resizepart

扩容分区的步骤。扩容只有两种情况，lvm（改 pv 所在分区的硬盘大小） 和非 lvm 纯分区的。无论是哪种，都得先扩容挂载路径所在的分区。推荐使用 parted 命令扩，且推荐使用最新版的 parted。新增硬盘扩到 lvm 里就不讲了，简单得不行。要先确保客户现场安装好新版本的 parted ，老版本的 parted 没有 resizepart 的命令，有条件的话把 gdisk 也可以安装上。

早期的 Linux 为了兼容 windows 的磁盘，只支持 MBR ，后面支持了 GPT。传统的老牌的分区工具是 fdisk，但是 fdisk 出道太早，只支持 MBR（Master Boot Record），并不支持 GPT（GUID Partition Table），无法操作超过2T的磁盘，因此 gdisk ，parted 等分区工具横空出世。两种类型分区表的信息存放不一样。所以我们扩容的时候得区分。

扩容硬盘的话，我们应该在扩硬盘大小之前先去看下该硬盘的分区表类型可以直接使用下面命令获取 Partition Table 的行确认

parted /dev/xxx p |& grep Table
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执行步骤
rescue 模式
如果扩容的分区有很多业务进程读写，例如我们的 data 分区。那就需要关机，进入 rescue 里去扩容了：

cdrom给机器挂载了一个centos7.x的minimal 的 iso(最好7.x的最新版，比如7.9)，
设置机器从 cdrom 启动，
选择 Troubleshooting –> Rescue a CentOS Linux system
进入菜单后选择 3) Skip to shell
触发硬盘重新扫描
假如硬盘容量是 2g 挂载在 /data 目录。下面所示，/dev/vda1 挂载在 /data 目录。纯分区扩容的话只能硬盘容量扩大，也即是虚拟化上修改，vmware 和 kvm 都能修改。

$ lsblk
NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda      8:0    0  10G  0 disk 
└─sda1   8:1    0  10G  0 part /
sr0     11:0    1   4M  0 rom  
vda    253:0    0   2G  0 disk 
└─vda1 253:1    0   2G  0 part /data
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如果修改后 lsblk 命令没识别，尝试下面的触发重新扫描:

# 查找硬盘属于的host，下面是 host2
$ ls -l /sys/block/vda
lrwxrwxrwx 1 root root 0 Aug 27 04:13 /sys/block/vda -> ../devices/pci0000:00/0000:00:05.0/virtio1/host2/target2:0:0/2:0:0:1/block/vda
# 触发扫描 host2
echo "- - -" > /sys/class/scsi_host/host2/scan
# 上面不行就下面这个
echo 1 > /sys/class/block/vda/device/rescan
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查看容量

$ lsblk
NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda      8:0    0  10G  0 disk 
└─sda1   8:1    0  10G  0 part /
vda      8:16   0   7G  0 disk 
└─vda1   8:17   0   2G  0 part /data
sr0     11:0    1   4M  0 rom
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非 lvm扩容，纯分区
msdos (MBR)
MBR 的分区表信息都是存放在头部的 512(446+64+2) 的 64 字节里。所以硬盘大小增加了，在 parted 操作硬盘的时候不会有啥警告信息：

$ lsblk
NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda      8:0    0  10G  0 disk 
└─sda1   8:1    0  10G  0 part /
sr0     11:0    1   4M  0 rom  
vda    253:0    0   2G  0 disk 
└─vda1 253:1    0   2G  0 part /data
$ lsblk
NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda      8:0    0  10G  0 disk 
└─sda1   8:1    0  10G  0 part /
sr0     11:0    1   4M  0 rom  
vda    253:0    0   7G  0 disk 
└─vda1 253:1    0   2G  0 part /data
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1、 umount 掉扩容分区所在的路径:

umount /data
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使用 parted 的 resizepart 扩容最后一个分区，下面信息可以看到，这个环境上最后一个分区的数字是 1，所以 resizepart 1

$ parted /dev/vda
GNU Parted 3.1
Using /dev/vda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p                                                                
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 7516MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 
Number  Start   End     Size    Type     File system  Flags
 1      1049kB  2147MB  2146MB  primary  xfs
(parted) resizepart 1     # <--- 最后一个分区的数字
End?  [2147MB]? 100%      # <--- 直接输入 100% 使用剩下所有分区                                             
(parted) p                                                                
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 7516MB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 
Number  Start   End     Size    Type     File system  Flags
 1      1049kB  7516MB  7515MB  primary  xfs
(parted) q                                                                
Information: You may need to update /etc/fstab.
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手动挂载下，查看容量增加了

$ mount /dev/vda1 /data
$ lsblk
NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda      8:0    0  10G  0 disk 
└─sda1   8:1    0  10G  0 part /
sr0     11:0    1   4M  0 rom  
vda    253:0    0   7G  0 disk 
└─vda1 253:1    0   7G  0 part /data
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可以 df -h |& grep /data 确认下，如果文件系统容量没上去就相应的命令扩容下，比如 xfs 使用下面扩容

xfs_growfs /dev/vda1
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GPT扩容
GPT 的分区表会在硬盘的头和尾巴都保存一份数据，所以扩大硬盘后，使用 parted 硬盘后 p 打印信息的时候在尾部找不到备份的数据，会告警，需要修复。先 umount 掉路径:

umount /data/
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上面可以看到硬盘大小从 2g 增加到 7g , 我们先 parted 扩容最后一个分区，先打印下信息

$ parted /dev/vda
GNU Parted 3.1
Using /dev/vda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p                                                                
Error: The backup GPT table is not at the end of the disk, as it should be.  This might mean that another operating system believes the disk is smaller.  Fix, by moving the backup to the end (and removing the old backup)?
Fix/Ignore/Cancel? Fix                                                    
Warning: Not all of the space available to /dev/vda appears to be used, you can fix the GPT to use all of the space (an extra 10485760 blocks) or continue with the current setting? 
Fix/Ignore? Fix                                                           
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 7516MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 
Number  Start   End     Size    File system  Name  Flags
 1      1049kB  2146MB  2145MB  xfs          1
(parted) resizepart 1        # <--- 上面最后一个分区的数字
End?  [2146MB]? 100%         # <--- 直接输入 100% 使用剩下所有分区                                                 
(parted) p                                                                
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 7516MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags: 
Number  Start   End     Size    File system  Name  Flags
 1      1049kB  7516MB  7515MB  xfs          1
(parted) q
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q 退出来后，能看到扩容成功，挂载后看到文件系统没扩容，所以得扩容

$ lsblk                                                   
NAME   MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda      8:0    0  10G  0 disk 
└─sda1   8:1    0  10G  0 part /
sr0     11:0    1   1G  0 rom  
sr1     11:1    1   4M  0 rom  
vda    253:0    0   7G  0 disk 
└─vda1 253:1    0   7G  0 part 
$ mount /dev/vda1 /data
$ df -h |& grep /data
/dev/vda1       2.0G   33M  2.0G   2% /data
$ xfs_growfs /dev/vda1
$ df -h |& grep /data  # 扩容完成
/dev/vda1       7.0G   33M  7.0G   1% /data
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lvm扩容
直接命令

$ lsblk
NAME             MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0               11:0    1  464K  0 rom  
sr1               11:1    1 1024M  0 rom  
vda              252:0    0   60G  0 disk 
├─vda1           252:1    0    2M  0 part 
├─vda2           252:2    0  200M  0 part /boot
└─vda3           252:3    0 39.8G  0 part 
  └─centos7-root 253:0    0 39.8G  0 lvm  /


$ parted /dev/vda
GNU Parted 3.1
Using /dev/vda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p                                                                
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 64.4GB 
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 
Number  Start   End     Size    Type     File system  Flags
 1      1049kB  3146kB  2097kB  primary
 2      3146kB  213MB   210MB   primary  xfs          boot
 3      213MB   42.9GB  42.7GB  primary               lvm
(parted) resizepart 3                                                     
End?  [42.9GB]? 100%
(parted) p                                                                
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 64.4GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags: 
Number  Start   End     Size    Type     File system  Flags
 1      1049kB  3146kB  2097kB  primary
 2      3146kB  213MB   210MB   primary  xfs          boot
 3      213MB   64.0GB  63.8GB  primary               lvm
(parted) quit
$ pvdisplay                                               
  --- Physical volume ---
  PV Name               /dev/vda3
  VG Name               centos7
  PV Size               39.80 GiB / not usable 0   
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              10189
  Free PE               0
  Allocated PE          10189
  PV UUID               VVXMV7-zVhi-NSVz-frrY-YKFg-BoJH-ir33p3
$ pvresize /dev/vda3
  Physical volume "/dev/vda3" changed
  1 physical volume(s) resized / 0 physical volume(s) not resized
扩容根分区所在的 lv

$ lvdisplay 
  --- Logical volume ---
  LV Path                /dev/centos7/root
  LV Name                root
  VG Name                centos7
  LV UUID                npjBgn-XPHe-dNS2-bJGd-kYp2-RayO-dWttAc
  LV Write Access        read/write
  LV Creation host, time localhost, 2018-06-30 14:35:21 +0800
  LV Status              available
  # open                 1
  LV Size                39.80 GiB
  Current LE             10189
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0
$ lvextend -l +100%FREE /dev/centos7/root 
  Size of logical volume centos7/root changed from 39.80 GiB (10189 extents) to 59.40 GiB (15207 extents).
  Logical volume centos7/root successfully resized.
$ xfs_growfs /dev/centos7/root
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