一、 lvm讲解
LVM是 Logical Volume Manager(逻辑卷管理)的简写，它由Heinz Mauelshagen在Linux 2.4内核上实现。LVM将一个或多个硬盘的分区在逻辑上集合，相当于一个大硬盘来使用，当硬盘的空间不够使用的时候，可以继续将其它的硬盘的分区加入其中，这样可以实现磁盘空间的动态管理，相对于普通的磁盘分区有很大的灵活性。
与传统的磁盘与分区相比，LVM为计算机提供了更高层次的磁盘存储。它使系统管理员可以更方便的为应用与用户分配存储空间。在LVM管理下的存储卷可以按需要随时改变大小与移除(可能需对文件系统工具进行升级)。LVM也允许按用户组对存储卷进行管理，允许管理员用更直观的名称(如"sales‘、 ‘development‘)代替物理磁盘名(如‘sda‘、‘sdb‘)来标识存储卷。 fdisk /dev/sdb
以下实例：
将/dev/sdb划分三个物理分区sdb1、sdb2、sdb3，创建物理卷,创建逻辑卷,并对逻辑卷及卷组进行扩容，缩容。
1. fdisk /dev/sdb n 建立三个分区，分别为1G,t 改变分区类型为8e
[[email protected] ~]# fdisk /dev/sdb
欢迎使用 fdisk (util-linux 2.23.2)。
更改将停留在内存中，直到您决定将更改写入磁盘。
使用写入命令前请三思。
命令(输入 m 获取帮助)：m
命令操作
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
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
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
命令(输入 m 获取帮助)：n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
分区号 (1-4，默认 1)：1
起始 扇区 (2048-41943039，默认为 2048)：
将使用默认值 2048
Last 扇区, +扇区 or +size{K,M,G} (2048-41943039，默认为 41943039)：+1G
分区 1 已设置为 Linux 类型，大小设为 1 GiB
命令(输入 m 获取帮助)：t
已选择分区 1
Hex 代码(输入 L 列出所有代码)：8e
已将分区“Linux”的类型更改为“Linux LVM”
[[email protected] ~]# fdisk -l 磁盘 /dev/sdb：21.5 GB, 21474836480 字节，41943040 个扇区 Units = 扇区 of 1 * 512 = 512 bytes 扇区大小(逻辑/物理)：512 字节 / 512 字节 I/O 大小(最小/最佳)：512 字节 / 512 字节 磁盘标签类型：dos 磁盘标识符：0x000a46f8 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 [[email protected] ~]#
2. 创建物理卷
yum install -y lvm2 默认最小化安装没有安装lvm包
pvcreate /dev/sdb1
pvcreate /dev/sdb2
pvcreate /dev/sdb3
pvdisplay 列出当前的物理卷
pvremove /dev/sdb3 删除物理卷
查看yum 源里pvcreate 命令的安装包名字是什么
[[email protected] ~]# yum provides "/*/pvcreate" 已加载插件：fastestmirror Loading mirror speeds from cached hostfile base/7/i386/filelists_db | 5.6 MB 00:00:40 extras/7/i386/filelists_db | 586 B 00:00:00 updates/7/i386/filelists_db | 3.2 MB 00:00:22 1:bash-completion-2.1-6.el7.noarch : Programmable completion for Bash 源 ：base 匹配来源： 文件名 ：/usr/share/bash-completion/completions/pvcreate7:lvm2-2.02.166-1.el7.i686 : Userland logical volume management tools 源 ：base 匹配来源： 文件名 ：/usr/sbin/pvcreate7:lvm2-2.02.166-1.el7_3.1.i686 : Userland logical volume management tools 源 ：updates 匹配来源： 文件名 ：/usr/sbin/pvcreate7:lvm2-2.02.166-1.el7_3.2.i686 : Userland logical volume management tools 源 ：updates 匹配来源： 文件名 ：/usr/sbin/pvcreate7:lvm2-2.02.166-1.el7_3.3.i686 : Userland logical volume management tools 源 ：updates 匹配来源： 文件名 ：/usr/sbin/pvcreate7:lvm2-2.02.166-1.el7_3.4.i686 : Userland logical volume management tools 源 ：updates 匹配来源： 文件名 ：/usr/sbin/pvcreate7:lvm2-2.02.166-1.el7_3.5.i686 : Userland logical volume management tools 源 ：updates 匹配来源： 文件名 ：/usr/sbin/pvcreate [[email protected] ~]#
创建物理卷时发现分区文件不存在，执行命令：partprobe，自动生成分区文件. 然后pvcreate 创建后三个物理卷后，pvdisplay进行查看.
[[email protected] ~]# pvcreate /dev/sdb1 Device /dev/sdb1 not found (or ignored by filtering). [[email protected] ~]# partprobe Error: Partition(s) 4 on /dev/sdb have been written, but we have been unable to inform the kernel of the change, probably because it/they are in use. As a result, the old partition(s) will remain in use. You should reboot now before making further changes.Warning: 无法以读写方式打开 /dev/sr0 (只读文件系统)。/dev/sr0 已按照只读方式打开。 [[email protected] ~]# ls /dev/sdb1 /dev/sdb1 [[email protected] ~]# ls /dev/sdb2 /dev/sdb2 [[email protected] ~]# ls /dev/sdb3 /dev/sdb3 [[email protected] ~]# pvcreate /dev/sdb1 WARNING: xfs signature detected on /dev/sdb1 at offset 0. Wipe it? [y/n]: y Wiping xfs 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 Physical volume "/dev/sdb3" successfully created. [[email protected] ~]# pvdisplay "/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 GSII2d-0LCa-KDPB-7sN2-inU2-Va8f-TJUC0c "/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 A5OfWM-eInj-nvkb-i35Z-KiXn-XQO5-I7zi10 "/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 NLu5gC-zHT5-egJ4-Nvi9-6dsY-cQET-ah7qnC [[email protected] ~]#
3. 创建逻辑卷
pvs 查看物理卷.
vgcreate vg1 /dev/sdb1 /dev/sdb2
vgdisplay或vgs查看逻辑卷
lvcreate -L 100M -n lv1 vg1
[[email protected] ~]# vgcreate vg1 /dev/sdb1 /dev/sdb2 Volume group "vg1" successfully created [[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 t5YfMC-DZ5b-5aYp-EEUW-V2We-MVNR-7AK9Tw [[email protected] ~]# vgs VG #PV #LV #SN Attr VSize VFree vg1 2 0 0 wz--n- 1.99g 1.99g [[email protected] ~]# lvcreate -L 100M -n lv1 vg1 Logical volume "lv1" created. [[email protected] ~]#
4. 格式化后挂载：
[[email protected] ~]# mkfs.ext4 /dev/vg1/lv1 mke2fs 1.42.9 (28-Dec-2013) 文件系统标签=OS type: Linux块大小=1024 (log=0) 分块大小=1024 (log=0)Stride=0 blocks, Stripe width=0 blocks25688 inodes, 102400 blocks5120 blocks (5.00%) reserved for the super user 第一个数据块=1Maximum filesystem blocks=3368550413 block groups8192 blocks per group, 8192 fragments per group1976 inodes per groupSuperblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729Allocating group tables: 完成 正在写入inode表: 完成 Creating journal (4096 blocks): 完成Writing superblocks and filesystem accounting information : 完成 [[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 1.1G 27G 4% / devtmpfs 240M 0 240M 0% /devtmpfs 248M 0 248M 0% /dev/shmtmpfs 248M 4.7M 244M 2% /run tmpfs 248M 0 248M 0% /sys/fs/cgroup/dev/sda1 197M 105M 93M 54% /boot /dev/mapper/vg1-lv1 93M 1.6M 85M 2% /mnt tmpfs 50M 0 50M 0% /run/user/0 [[email protected] ~]# ls /dev/mapper/vg1-lv1 /dev/mapper/vg1-lv1 [[email protected] ~]# ls -l /dev/mapper/vg1-lv1 lrwxrwxrwx 1 root root 7 8月 17 02:41 /dev/mapper/vg1-lv1 -> ../dm-0 [[email protected] ~]# ls -l /dev/vg1/lv1 lrwxrwxrwx 1 root root 7 8月 17 02:41 /dev/vg1/lv1 -> ../dm-0 [[email protected] ~]#
5. 扩容逻辑卷:
扩容：
umount /mnt
lvresize -L 300M /dev/vg1/lv1
resize2fs /dev/vg1/lv1
减容：
e2fsck -f /dev/vg1/lv1 lvresize -L 100M /dev/vg1/lv1 vgs mount /dev/vg1/lv1/ /mnt df -h
[[email protected] ~]# lvresize -L 300M /dev/vg1/lv1 Size of logical volume vg1/lv1 changed from 100.00 MiB (25 extents) to 300.00 MiB (75 extents). Logical volume vg1/lv1 successfully resized. [[email protected] ~]# e2fsck -f /dev/vg1/lv1e2fsck 1.42.9 (28-Dec-2013) /dev/vg1/lv1 is mounted. e2fsck: 无法继续, 中止. [[email protected] ~]# resize2fs /dev/vg1/lv1 resize2fs 1.42.9 (28-Dec-2013) Filesystem at /dev/vg1/lv1 is mounted on /mnt; on-line re sizing requiredold_desc_blocks = 1, new_desc_blocks = 3The filesystem on /dev/vg1/lv1 is now 307200 blocks long. [[email protected] ~]# df -h 文件系统 容量 已用 可用 已用% 挂载点 /dev/sda3 28G 1.1G 27G 4% / devtmpfs 240M 0 240M 0% /dev tmpfs 248M 0 248M 0% /dev/shm tmpfs 248M 4.7M 244M 2% /run tmpfs 248M 0 248M 0% /sys/fs/cgrou p/dev/sda1 197M 105M 93M 54% /boot tmpfs 50M 0 50M 0% /run/user/0/dev/mapper/vg1-lv1 287M 2.0M 270M 1% /mnt [[email protected] ~]#
[[email protected] ~]# umount /mnt [[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: 13/75088 files (7.7% non-contiguous), 15639 /307200 blocks[[email protected] ~]# resize2fs /dev/vg1/lv1 100M resize2fs 1.42.9 (28-Dec-2013) Resizing the filesystem on /dev/vg1/lv1 to 102400 (1k) bl ocks.The filesystem on /dev/vg1/lv1 is now 102400 blocks long. [[email protected] ~]# lvresize -L 100M /dev/vg1/lv1 WARNING: Reducing active logical volume to 100.00 MiB. THIS MAY DESTROY YOUR DATA (filesystem etc.)Do you really want to reduce vg1/lv1? [y/n]: y Size of logical volume vg1/lv1 changed from 300.00 MiB (75 extents) to 100.00 MiB (25 extents). Logical volume vg1/lv1 successfully resized. [[email protected] ~]# vgs VG #PV #LV #SN Attr VSize VFree vg1 2 1 0 wz--n- 1.99g 1.89g [[email protected] ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert lv1 vg1 -wi-a----- 100.00m [[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 1.1G 27G 4% / devtmpfs 240M 0 240M 0% /dev tmpfs 248M 0 248M 0% /dev/shm tmpfs 248M 4.7M 244M 2% /run tmpfs 248M 0 248M 0% /sys/fs/cgroup/dev/sda1 197M 105M 93M 54% /boot tmpfs 50M 0 50M 0% /run/user/0/dev/mapper/vg1-lv1 93M 1.6M 86M 2% /mnt [[email protected] ~]# ls /mnt/ fxq lost+found
6. xfs 扩容：
不用卸载lv1
lvresize -L 300M /dev/vg1/lv1
xfs_growfs /dev/vg1/lv1
7. 扩展卷组：
fdisk /dev/sdb 新增/dev/sdb5（逻辑分区8e）2G
pvcreate /dev/sdb5
vgextend vg1 /dev/sdb5
lvresize -L 100M /dev/vg1/lv1 重新设置卷大小
[[email protected] ~]# vgextend vg1 /dev/sdb3 Volume group "vg1" successfully extended [[email protected] ~]# vgs VG #PV #LV #SN Attr VSize VFree vg1 3 1 0 wz--n- 2.99g 2.70g [[email protected] ~]# lvresize -L 3000M /dev/vg1/lv1 Size of logical volume vg1/lv1 changed from 300.00 MiB (75 extents) to 2.93 GiB (750 extents). Logical volume vg1/lv1 successfully resized. [[email protected] ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Mov e Log Cpy%Sync Convert lv1 vg1 -wi-ao---- 2.93g [[email protected] ~]# umount /mnt [[email protected] ~]# e2fsck -f /dev/vg1/lv1 [[email protected] ~]# resize2fs /dev/vg1/lv1 [[email protected] ~]# mount /dev/vg1/lv1 /mnt
二、 磁盘故障小案例
编辑/etc/fstab 内容，出错后，开机有如下提示，输入root密码进入：
时间： 2024-11-06 03:17:50