lvm及磁盘故障案列

Posted 2020-10-30

lvm讲解

1. 把磁盘/dev/sdb分为三个区，t可以指定类型，类型为LVM（id为8e）

   设备 Boot      Start         End      Blocks   Id  System
   /dev/sdb1            2048     2099199     1048576   8e  Linux LVM
   /dev/sdb2         2099200     4196351     1048576   8e  Linux LVM
   /dev/sdb3         4196352     6293503     1048576   8e  Linux LVM

2. 创建物理卷

   用yum provides ”/*/pvcreate“命令查找lvm包，yum install -y lvm2安装

   • 可以用partprobe命令生成/dev/sdb1文件
   • 使用pvreate /dev/sdb1 命令分别创建三个物理卷

     [[email protected] ~]# pvcreate /dev/sdb1 
     WARNING: ext4 signature detected on /dev/sdb1 at offset 1080. Wipe it? [y/n]: y
     Wiping ext4 signature on /dev/sdb1.
     Physical volume “/dev/sdb1” successfully created.
     [[email protected] ~]# pvcreate /dev/sdb2
     Physical volume ”/dev/sdb2“ successfully created.
     [[email protected] ~]# pvcreate /dev/sdb3
     WARNING: dos signature detected on /dev/sdb3 at offset 510. Wipe it? [y/n]: y
     Wiping dos signature on /dev/sdb3.
     Physical volume “/dev/sdb3” successfully created.

   • 使用pvdisplay查看系统中的物理卷

     [[email protected] ~]# pvdisplay
     ”/dev/sdb1“ is a new physical volume of ”1.00 GiB“
     --- NEW Physical volume ---
     PV Name               /dev/sdb1
     VG Name               
     PV Size               1.00 GiB
     Allocatable           NO
     PE Size               0   
     Total PE              0
     Free PE               0
     Allocated PE          0
     PV UUID               qrwO8j-8kOv-OfEh-bNed-9TcG-5Qyq-scRpyb
     “/dev/sdb2” is a new physical volume of “1.00 GiB”
     --- NEW Physical volume ---
     PV Name               /dev/sdb2
     VG Name               
     PV Size               1.00 GiB
     Allocatable           NO
     PE Size               0   
     Total PE              0
     Free PE               0
     Allocated PE          0
     PV UUID               hPPtFs-Dfmo-zrnZ-mYUA-41Sy-wgfy-Zz0M4P
     “/dev/sdb3” is a new physical volume of “1.00 GiB”
     --- NEW Physical volume ---
     PV Name               /dev/sdb3
     VG Name               
     PV Size               1.00 GiB
     Allocatable           NO
     PE Size               0   
     Total PE              0
     Free PE               0
     Allocated PE          0
     PV UUID               HrV293-eP3T-YJTM-vakP-eKXR-ykLg-xoFq66

   • pvs查看物理卷

     [[email protected] ~]# pvs
     PV         VG Fmt  Attr PSize PFree
     /dev/sdb1     lvm2 ---  1.00g 1.00g
     /dev/sdb2     lvm2 ---  1.00g 1.00g
     /dev/sdb3     lvm2 ---  1.00g 1.00g

3. 创建卷组，vgcreate

   [[email protected] ~]# vgcreate vg1 /dev/sdb1 /dev/sdb2
   Volume group ”vg1“ successfully created

   • vgdisplay和vgs查看卷组信息

     [[email protected] ~]# vgdisplay
     --- Volume group ---
     VG Name               vg1
     System ID             
     Format                lvm2
     Metadata Areas        2
     Metadata Sequence No  1
     VG Access             read/write
     VG Status             resizable
     MAX LV                0
     Cur LV                0
     Open LV               0
     Max PV                0
     Cur PV                2
     Act PV                2
     VG Size               1.99 GiB
     PE Size               4.00 MiB
     Total PE              510
     Alloc PE / Size       0 / 0   
     Free  PE / Size       510 / 1.99 GiB
     VG UUID               ufmtbK-zC4s-wsL2-mBEP-HlMy-Vg2Q-dPnkgV

     [[email protected] ~]# vgs
     VG  #PV #LV #SN Attr   VSize VFree
     vg1   2   0   0 wz--n- 1.99g 1.99g
     [[email protected] ~]# 

   • vgremove删除卷组命令
4. 创建逻辑卷，lvcreate -L 100M -n lv1 vg1从vg1里面划分名为lv1，大小为100M的逻辑卷

   [[email protected] ~]# lvcreate -L 100M -n lv1 vg1
   Logical volume ”lv1“ created.

5. 格式化，mkfs.ext4 /dev/vg1/lv1
6. 挂载逻辑卷

   [[email protected] ~]# mount /dev/vg1/lv1 /mnt/
   [[email protected] ~]# df -h
   文件系统             容量  已用  可用 已用% 挂载点
   /dev/sda3             28G  1.2G   27G    5% /
   devtmpfs             483M     0  483M    0% /dev
   tmpfs                493M     0  493M    0% /dev/shm
   tmpfs                493M  6.8M  486M    2% /run
   tmpfs                493M     0  493M    0% /sys/fs/cgroup
   /dev/sda1            197M  109M   88M   56% /boot
   tmpfs                 99M     0   99M    0% /run/user/0
   /dev/mapper/vg1-lv1   93M  1.6M   85M    2% /mnt

7. 扩容逻辑卷
   • 先umount（xfs不能卸载）
   • lvresize -L 200M /dev/vg1/lv1 重新设置卷大小

     [[email protected] ~]# lvresize -L 200M /dev/vg1/lv1 
     Size of logical volume vg1/lv1 changed from 100.00 MiB (25 extents) to 200.00 MiB (50 extents).
     Logical volume vg1/lv1 successfully resized.

   • e2fsck -f /dev/vg1/lv1 检查磁盘错误（ext4执行）

     [[email protected] ~]# e2fsck -f /dev/vg1/lv1 
     e2fsck 1.42.9 (28-Dec-2013)
     第一步: 检查inode,块,和大小
     第二步: 检查目录结构
     第3步: 检查目录连接性
     Pass 4: Checking reference counts
     第5步: 检查簇概要信息
     /dev/vg1/lv1: 11/25688 files (9.1% non-contiguous), 8896/102400 blocks

   • resize2fs /dev/vg1/lv1 更新逻辑卷信息（ext4执行）

     [email protected] ~]# resize2fs /dev/vg1/lv1 
     resize2fs 1.42.9 (28-Dec-2013)
     Resizing the filesystem on /dev/vg1/lv1 to 204800 (1k) blocks.
     The filesystem on /dev/vg1/lv1 is now 204800 blocks long.

   • xfs_growfs /dev/vg1/lv1 xfs文件系统需要执行
8. 缩减逻辑卷（xfs不支持）
   • 先umount
   • e2fsck -f /dev/vg1/lv1 检查磁盘错误（ext）
   • resize2fs /dev/vg1/lv1 100M 更新逻辑卷信息（ext）
   • lvresize -L 100M /dev/vg1/lv1 重新设置卷大小
9. 扩容卷组
   • fdisk /dev/sdb新增/dev/sdb3(8e)
   • pvcreate /dev/sdb3创建物理卷
   • vgextend vg1 /dev/sdb3加入卷组
   • lvresize -L 500M /dev/vg1/lv1重新设置卷大小

硬盘故障案例

• 做完lvm进不了系统，由于磁盘挂载错误，磁盘不能正常挂载到挂载点
• 输入root密码可以进入，删除错误的挂载点，vim /etc/fstab删除最后一行
• 重启