【笔记】Linux LVM使用和迁移

LVM使用

磁盘管理技术，在线磁盘扩容和缩容，数据迁移，条带卷（增加性能）
PV（physical volume），物理卷，系统的裸盘或者分区做成一个PV，是1：1的。
VG（volume group），卷组，将1个或多个PV加入到VG中，可以类比为存储池。
LV（logic voume），逻辑卷，从vg中取一定大小的空间，可以类比为划lun，lv最终呈现给主机的就是硬盘。
使用的时候需要把LV格式化文件系统。

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[root@localhost ~]# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda           8:0    0   20G  0 disk
sdb           8:16   0   20G  0 disk
sr0          11:0    1 1024M  0 rom
nvme0n1     259:0    0   40G  0 disk
├─nvme0n1p1 259:1    0    1G  0 part /boot
└─nvme0n1p2 259:2    0   20G  0 part
  └─rl-root 253:0    0   20G  0 lvm  /
[root@localhost ~]# pvcreate /dev/sda
  Physical volume "/dev/sda" successfully created.
[root@localhost ~]# pvcreate /dev/sdb
  Physical volume "/dev/sdb" successfully created.
[root@localhost ~]# vgcreate vg0 /dev/sda
  Volume group "vg0" successfully created
[root@localhost ~]# pvs
  PV             VG  Fmt  Attr PSize   PFree
  /dev/nvme0n1p2 rl  lvm2 a--   20.00g      0
  /dev/sda       vg0 lvm2 a--  <20.00g <20.00g
  /dev/sdb           lvm2 ---   20.00g  20.00g
[root@localhost ~]# vgs
  VG  #PV #LV #SN Attr   VSize   VFree
  rl    1   1   0 wz--n-  20.00g      0
  vg0   1   0   0 wz--n- <20.00g <20.00g
[root@localhost ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/nvme0n1p2
  VG Name               rl
  PV Size               20.00 GiB / not usable 4.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              5120
  Free PE               0
  Allocated PE          5120
  PV UUID               ZrllZr-dzmY-K5k8-bKrL-8V3D-jcNp-3o0Ir6

  --- Physical volume ---
  PV Name               /dev/sda
  VG Name               vg0
  PV Size               20.00 GiB / not usable 4.00 MiB
  Allocatable           yes
  PE Size               4.00 MiB
  Total PE              5119
  Free PE               5119
  Allocated PE          0
  PV UUID               DEOfNN-1Rqt-7KU7-4gXu-nuwr-Sja6-93lnCW

  "/dev/sdb" is a new physical volume of "20.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdb
  VG Name
  PV Size               20.00 GiB
  Allocatable           NO
  PE Size               0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               lZB416-hIyr-eKiQ-4eLW-2iue-bb3N-ulXIjp

[root@localhost ~]# vgdisplay
  --- Volume group ---
  VG Name               rl
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               1
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               20.00 GiB
  PE Size               4.00 MiB
  Total PE              5120
  Alloc PE / Size       5120 / 20.00 GiB
  Free  PE / Size       0 / 0
  VG UUID               tsZJRs-7z9T-s9jI-ODbm-VfcM-ltyQ-YG4F8i

  --- Volume group ---
  VG Name               vg0
  System ID
  Format                lvm2
  Metadata Areas        1
  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                1
  Act PV                1
  VG Size               <20.00 GiB
  PE Size               4.00 MiB
  Total PE              5119
  Alloc PE / Size       0 / 0
  Free  PE / Size       5119 / <20.00 GiB
  VG UUID               B5bdof-PwK5-VZeB-vsSs-H3y5-AZhb-qob20r

[root@localhost ~]# lvcreate -L 15G -n lv01 vg0
  Logical volume "lv01" created.
[root@localhost ~]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 -wi-a----- 15.00g
[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/rl/root
  LV Name                root
  VG Name                rl
  LV UUID                cchRZb-w3U5-s6Kh-mfLR-kr5a-TEvn-mGEe89
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-04-28 13:02:41 +0800
  LV Status              available
  # open                 1
  LV Size                20.00 GiB
  Current LE             5120
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

  --- Logical volume ---
  LV Path                /dev/vg0/lv01
  LV Name                lv01
  VG Name                vg0
  LV UUID                1YSxcC-9Tdr-LfeD-KZfA-brbx-1UWY-kbwXBH
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-06-14 20:07:47 +0800
  LV Status              available
  # open                 0
  LV Size                15.00 GiB
  Current LE             3840
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1

[root@localhost ~]# mkfs.xfs /dev/vg0/lv01
meta-data=/dev/vg0/lv01          isize=512    agcount=4, agsize=983040 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0 inobtcount=0
data     =                       bsize=4096   blocks=3932160, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@localhost ~]# mkdir /lv01
[root@localhost ~]# mount /dev/vg0/lv01 /lv01/
[root@localhost ~]# df -Th
Filesystem           Type      Size  Used Avail Use% Mounted on
devtmpfs             devtmpfs  3.8G     0  3.8G   0% /dev
tmpfs                tmpfs     3.8G     0  3.8G   0% /dev/shm
tmpfs                tmpfs     3.8G  9.0M  3.8G   1% /run
tmpfs                tmpfs     3.8G     0  3.8G   0% /sys/fs/cgroup
/dev/mapper/rl-root  xfs        20G  2.5G   18G  13% /
/dev/nvme0n1p1       xfs      1014M  232M  783M  23% /boot
tmpfs                tmpfs     766M     0  766M   0% /run/user/0
/dev/mapper/vg0-lv01 xfs        15G  140M   15G   1% /lv01
[root@localhost ~]# cp -r /etc/ /lv01/
[root@localhost ~]# cd /lv01/
[root@localhost lv01]# ls
etc
[root@localhost lv01]# ls etc/
adjtime                  ethertypes     libaudit.conf              pam.d                   skel
aliases                  exports        libblockdev                passwd                  smartmontools

补充：

  1. pvdisplay中，PE Size的大小为4M，Total PE是PE的数量，/dev/sda在创建pv和vg之后，PE数量为5119，4*5119=20,476，正好是20G大小（缺的4M用于放元数据）。
  2. 由于/dev/sdb没有加入卷组，还没有划分PE，所以在pvdisplay中PE为0

LVM扩容

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[root@localhost lv01]# pvs
  PV             VG  Fmt  Attr PSize   PFree
  /dev/nvme0n1p2 rl  lvm2 a--   20.00g     0
  /dev/sda       vg0 lvm2 a--  <20.00g <5.00g
  /dev/sdb           lvm2 ---   20.00g 20.00g
[root@localhost lv01]# vgs
  VG  #PV #LV #SN Attr   VSize   VFree
  rl    1   1   0 wz--n-  20.00g     0
  vg0   1   1   0 wz--n- <20.00g <5.00g
[root@localhost lv01]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 -wi-ao---- 15.00g
[root@localhost lv01]# vgextend vg0 /dev/sdb
  Volume group "vg0" successfully extended
[root@localhost lv01]# vgs
  VG  #PV #LV #SN Attr   VSize  VFree
  rl    1   1   0 wz--n- 20.00g     0
  vg0   2   1   0 wz--n- 39.99g 24.99g
[root@localhost lv01]# pvs
  PV             VG  Fmt  Attr PSize   PFree
  /dev/nvme0n1p2 rl  lvm2 a--   20.00g      0
  /dev/sda       vg0 lvm2 a--  <20.00g  <5.00g
  /dev/sdb       vg0 lvm2 a--  <20.00g <20.00g
[root@localhost lv01]# lvextend -L 25G /dev/vg0/lv01
  Size of logical volume vg0/lv01 changed from 15.00 GiB (3840 extents) to 25.00 GiB (6400 extents).
  Logical volume vg0/lv01 successfully resized.
[root@localhost lv01]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 -wi-ao---- 25.00g
[root@localhost lv01]# df -Th
Filesystem           Type      Size  Used Avail Use% Mounted on
devtmpfs             devtmpfs  3.8G     0  3.8G   0% /dev
tmpfs                tmpfs     3.8G     0  3.8G   0% /dev/shm
tmpfs                tmpfs     3.8G  9.0M  3.8G   1% /run
tmpfs                tmpfs     3.8G     0  3.8G   0% /sys/fs/cgroup
/dev/mapper/rl-root  xfs        20G  2.5G   18G  13% /
/dev/nvme0n1p1       xfs      1014M  232M  783M  23% /boot
tmpfs                tmpfs     766M     0  766M   0% /run/user/0
/dev/mapper/vg0-lv01 xfs        15G  167M   15G   2% /lv01
[root@localhost lv01]# xfs_growfs /dev/vg0/lv01
meta-data=/dev/mapper/vg0-lv01   isize=512    agcount=4, agsize=983040 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0 inobtcount=0
data     =                       bsize=4096   blocks=3932160, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 3932160 to 6553600
[root@localhost lv01]# df -Th
Filesystem           Type      Size  Used Avail Use% Mounted on
devtmpfs             devtmpfs  3.8G     0  3.8G   0% /dev
tmpfs                tmpfs     3.8G     0  3.8G   0% /dev/shm
tmpfs                tmpfs     3.8G  9.0M  3.8G   1% /run
tmpfs                tmpfs     3.8G     0  3.8G   0% /sys/fs/cgroup
/dev/mapper/rl-root  xfs        20G  2.5G   18G  13% /
/dev/nvme0n1p1       xfs      1014M  232M  783M  23% /boot
tmpfs                tmpfs     766M     0  766M   0% /run/user/0
/dev/mapper/vg0-lv01 xfs        25G  238M   25G   1% /lv01

LVM迁移

前情提要

数据迁移，想要数据迁移的更快，那我们来剖析一下数据从哪里来到哪里去。
Q：拷贝硬盘的上数据块和拷贝硬盘中的文件哪个比较快？

  • 拷贝硬盘数据块：直接读取硬盘数据块然后写入另一块硬盘。
  • 拷贝硬盘中的文件：操作系统，使用文件系统读取文件/目录，读取硬盘的数据块，然后复制到另一个文件系统之中，然后再写入硬盘。

io的路径越短，拷贝越快，再加上不需要计算，就更快。
但是要考虑场景，如果1个1TB硬盘，只用了20G空间，那么拷贝文件肯定比数据块更快。如果1TB硬盘，用了990G，那么拷贝数据块肯定更快
读取硬盘上的数据块的方案有很多，例如存储硬盘1TB空间，到主机A上，需要将数据迁移到新的存储上，再新的存储上划了1TB空间，映射给主机A，可以通过主机A使用dd将硬盘上所有数据块复制

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[root@oracle ~]# lsblk
NAME                         MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                            8:0    0   50G  0 disk
├─sda1                         8:1    0  500M  0 part /boot
└─sda2                         8:2    0 49.5G  0 part
  ├─vg_fengyh-lv_root (dm-0) 253:0    0 45.6G  0 lvm  /
  └─vg_fengyh-lv_swap (dm-1) 253:1    0  3.9G  0 lvm  [SWAP]
sdb                            8:16   0   40G  0 disk /u01
sr0                           11:0    1 1024M  0 rom
sdc                            8:32   0    2G  0 disk
└─dir01-lv_dir01 (dm-2)      253:2    0    2G  0 lvm  /dir01
sdd                            8:48   0    2G  0 disk
[root@oracle ~]# dd if=/dev/sdc of=/dev/sdd
记录了4194304+0 的读入
记录了4194304+0 的写出
2147483648字节(2.1 GB)已复制，40.835 秒，52.6 MB/秒
[root@oracle ~]# blkid
/dev/mapper/vg_fengyh-lv_root: UUID="b6f017ca-d1af-4345-8765-fee44efc347e" TYPE="ext4"
/dev/sda1: UUID="4dc4dbdd-a488-4347-b07e-71fad64aa50c" TYPE="ext4"
/dev/sda2: UUID="Oo0EHf-wuQI-OHbK-j2ir-EzMS-Xc3j-dQX4Jj" TYPE="LVM2_member"
/dev/mapper/vg_fengyh-lv_swap: UUID="1e23f7f0-5bf0-49ca-862a-0099130b5706" TYPE="swap"
/dev/sdb: UUID="0a97bf23-5405-4e5f-a2ca-f82743c119af" TYPE="ext4"
/dev/sdc: UUID="cguMcl-dj4u-qXfF-mfZp-DhiJ-lK14-bqF3lU" TYPE="LVM2_member"
/dev/sdd: UUID="cguMcl-dj4u-qXfF-mfZp-DhiJ-lK14-bqF3lU" TYPE="LVM2_member"
/dev/mapper/dir01-lv_dir01: UUID="deece864-f923-482e-8375-b882a31700d2" TYPE="ext4"
#/dev/sdd在复制之前是裸盘，复制时也复制了文件系统，UUID也与/dev/sdc保持一致

换一种思路就是通过存储直接复制
dd方案只适合离线迁移，要停业务
Linux lvm（逻辑卷），数据迁移。

原理

按照“LVM使用”所述，PE与LE是一一对应关系，如下图：

那么迁移步骤就可以分为2部分：

  1. 逻辑卷镜像（lvconvert）：创建一个新的相同大小的pv，将LE由与PE一一对应关系变成1:2，在做完镜像之后，新指向的PE会与源PE进行数据对拷，实现数据的同步
  2. 拆分镜像：把初始的PE与LE关系拆除，LE与新PE对应关系变为1:1

实验

创建被迁移的源卷/dev/sda，并放入数据：

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[root@localhost ~]# pvcreate /dev/sda
  Physical volume "/dev/sda" successfully created.
[root@localhost ~]# vgcreate vg0 /dev/sda
  Volume group "vg0" successfully created
[root@localhost ~]# lvcreate -L 5G -n lv01 vg0
WARNING: xfs signature detected on /dev/vg0/lv01 at offset 0. Wipe it? [y/n]: y
  Wiping xfs signature on /dev/vg0/lv01.
  Logical volume "lv01" created.
[root@localhost ~]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 -wi-a-----  5.00g
[root@localhost ~]# mkfs.xfs /dev/vg0/lv01
meta-data=/dev/vg0/lv01          isize=512    agcount=4, agsize=327680 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0 inobtcount=0
data     =                       bsize=4096   blocks=1310720, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@localhost ~]# mount /dev/vg0/lv01 /lv01/
[root@localhost ~]# cp -r /etc/ /lv01/
[root@localhost ~]# cd /lv01/
[root@localhost lv01]# ls
etc

逻辑卷镜像：lvconvert -m 1 [lv] [要被镜像的pv]

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[root@localhost lv01]# pvs
  PV             VG  Fmt  Attr PSize   PFree
  /dev/nvme0n1p2 rl  lvm2 a--   20.00g      0
  /dev/sda       vg0 lvm2 a--  <20.00g <15.00g
[root@localhost lv01]# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda           8:0    0   20G  0 disk
└─vg0-lv01  253:1    0    5G  0 lvm  /lv01
sdb           8:16   0   20G  0 disk
sr0          11:0    1 1024M  0 rom
nvme0n1     259:0    0   40G  0 disk
├─nvme0n1p1 259:1    0    1G  0 part /boot
└─nvme0n1p2 259:2    0   20G  0 part
  └─rl-root 253:0    0   20G  0 lvm  /
[root@localhost lv01]# pvcreate /dev/sdb
  Physical volume "/dev/sdb" successfully created.
[root@localhost lv01]# vgextend vg0 /dev/sdb
  Volume group "vg0" successfully extended

#-m 1代表镜像一份
[root@localhost lv01]# lvconvert -m 1 /dev/vg0/lv01 /dev/sdb
Are you sure you want to convert linear LV vg0/lv01 to raid1 with 2 images enhancing resilience? [y/n]: y
  Logical volume vg0/lv01 successfully converted.

#lvs查看拷贝进度
[root@localhost lv01]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 rwi-aor---  5.00g                                    6.25
[root@localhost lv01]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 rwi-aor---  5.00g                                    18.75
[root@localhost lv01]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/rl/root
  LV Name                root
  VG Name                rl
  LV UUID                cchRZb-w3U5-s6Kh-mfLR-kr5a-TEvn-mGEe89
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-04-28 13:02:41 +0800
  LV Status              available
  # open                 1
  LV Size                20.00 GiB
  Current LE             5120
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

  --- Logical volume ---
  LV Path                /dev/vg0/lv01
  LV Name                lv01
  VG Name                vg0
  LV UUID                UzEOmf-ko6J-N8NM-fbe0-l6Fe-VaJW-3sXTMx
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-06-14 20:41:05 +0800
  LV Status              available
  # open                 1
  LV Size                5.00 GiB
  Current LE             1280
  Mirrored volumes       2
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1

[root@localhost lv01]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/nvme0n1p2
  VG Name               rl
  PV Size               20.00 GiB / not usable 4.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              5120
  Free PE               0
  Allocated PE          5120
  PV UUID               ZrllZr-dzmY-K5k8-bKrL-8V3D-jcNp-3o0Ir6

  --- Physical volume ---
  PV Name               /dev/sda
  VG Name               vg0
  PV Size               20.00 GiB / not usable 4.00 MiB
  Allocatable           yes
  PE Size               4.00 MiB
  Total PE              5119
  Free PE               3838
  Allocated PE          1281
  PV UUID               ZzqIq7-ydPa-E1qk-c0L5-At4e-cCv5-dpDrRU

  --- Physical volume ---
  PV Name               /dev/sdb
  VG Name               vg0
  PV Size               20.00 GiB / not usable 4.00 MiB
  Allocatable           yes
  PE Size               4.00 MiB
  Total PE              5119
  Free PE               3838
  Allocated PE          1281
  PV UUID               hpoGGr-cU1b-pb1g-MQwM-kVTT-ahdc-J0OOc2

[root@localhost lv01]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 rwi-aor---  5.00g                                    100.00

拆除镜像：lvconvert -m 0 [lv] [要被拆除镜像的Pv]

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[root@localhost lv01]# lvconvert -m 0 /dev/vg0/lv01 /dev/sda
Are you sure you want to convert raid1 LV vg0/lv01 to type linear losing all resilience? [y/n]: y
  Logical volume vg0/lv01 successfully converted.
[root@localhost lv01]# pvs
  PV             VG  Fmt  Attr PSize   PFree
  /dev/nvme0n1p2 rl  lvm2 a--   20.00g      0
  /dev/sda       vg0 lvm2 a--  <20.00g <20.00g
  /dev/sdb       vg0 lvm2 a--  <20.00g <15.00g
[root@localhost lv01]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/nvme0n1p2
  VG Name               rl
  PV Size               20.00 GiB / not usable 4.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              5120
  Free PE               0
  Allocated PE          5120
  PV UUID               ZrllZr-dzmY-K5k8-bKrL-8V3D-jcNp-3o0Ir6

  --- Physical volume ---
  PV Name               /dev/sda
  VG Name               vg0
  PV Size               20.00 GiB / not usable 4.00 MiB
  Allocatable           yes
  PE Size               4.00 MiB
  Total PE              5119
  Free PE               5119
  Allocated PE          0
  PV UUID               ZzqIq7-ydPa-E1qk-c0L5-At4e-cCv5-dpDrRU

  --- Physical volume ---
  PV Name               /dev/sdb
  VG Name               vg0
  PV Size               20.00 GiB / not usable 4.00 MiB
  Allocatable           yes
  PE Size               4.00 MiB
  Total PE              5119
  Free PE               3839
  Allocated PE          1280
  PV UUID               hpoGGr-cU1b-pb1g-MQwM-kVTT-ahdc-J0OOc2

[root@localhost lv01]# vgreduce vg0 /dev/sda
  Removed "/dev/sda" from volume group "vg0"
[root@localhost lv01]# pvs
  PV             VG  Fmt  Attr PSize   PFree
  /dev/nvme0n1p2 rl  lvm2 a--   20.00g      0
  /dev/sda           lvm2 ---   20.00g  20.00g
  /dev/sdb       vg0 lvm2 a--  <20.00g <15.00g
[root@localhost lv01]# pvremove /dev/sda
  Labels on physical volume "/dev/sda" successfully wiped.

把LV导出，导入到另一个节点

实现数据复制到另一块物理盘上，把物理盘拔出插到其他业务主机，实现备份。
格式：lvconvert --splitmirrors Number -n --name LVnew LV
vgsplit VG VG PV或vgsplit -n|--name LV VG VG

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[root@localhost ~]# pvs
  PV             VG  Fmt  Attr PSize   PFree
  /dev/nvme0n1p2 rl  lvm2 a--   20.00g      0
  /dev/sdb       vg0 lvm2 a--  <20.00g <15.00g
[root@localhost ~]# vgs
  VG  #PV #LV #SN Attr   VSize   VFree
  rl    1   1   0 wz--n-  20.00g      0
  vg0   1   1   0 wz--n- <20.00g <15.00g
[root@localhost ~]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 -wi-a-----  5.00g
[root@localhost ~]# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda           8:0    0   20G  0 disk
sdb           8:16   0   20G  0 disk
└─vg0-lv01  253:1    0    5G  0 lvm
sr0          11:0    1 1024M  0 rom
nvme0n1     259:0    0   40G  0 disk
├─nvme0n1p1 259:1    0    1G  0 part /boot
└─nvme0n1p2 259:2    0   20G  0 part
  └─rl-root 253:0    0   20G  0 lvm  /
[root@localhost ~]# pvcreate /dev/sda
  Physical volume "/dev/sda" successfully created.
[root@localhost ~]# vgextend vg0 /dev/sda
  Volume group "vg0" successfully extended
[root@localhost ~]# lvconvert -m 1 /dev/vg0/lv01 /dev/sda
Are you sure you want to convert linear LV vg0/lv01 to raid1 with 2 images enhancing resilience? [y/n]: y
  Logical volume vg0/lv01 successfully converted.
[root@localhost ~]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 rwi-a-r---  5.00g                                    18.75
[root@localhost ~]# lv
lvchange        lvdisplay       lvmconfig       lvmdump         lvmsadc         lvremove        lvs
lvconvert       lvextend        lvmdevices      lvm_import_vdo  lvmsar          lvrename        lvscan
lvcreate        lvm             lvmdiskscan     lvmpolld        lvreduce        lvresize
[root@localhost ~]# man lvconvert
[root@localhost ~]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 rwi-a-r---  5.00g                                    100.00

[root@localhost ~]# lvconvert  --splitmirrors 1 -n lv02 /dev/vg0/lv01
Are you sure you want to split raid1 LV vg0/lv01 losing all resilience? [y/n]: y
[root@localhost ~]# pvs
  PV             VG  Fmt  Attr PSize   PFree
  /dev/nvme0n1p2 rl  lvm2 a--   20.00g      0
  /dev/sda       vg0 lvm2 a--  <20.00g <15.00g
  /dev/sdb       vg0 lvm2 a--  <20.00g <15.00g
[root@localhost ~]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 -wi-a-----  5.00g
  lv02 vg0 -wi-a-----  5.00g
[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/rl/root
  LV Name                root
  VG Name                rl
  LV UUID                cchRZb-w3U5-s6Kh-mfLR-kr5a-TEvn-mGEe89
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-04-28 13:02:41 +0800
  LV Status              available
  # open                 1
  LV Size                20.00 GiB
  Current LE             5120
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

  --- Logical volume ---
  LV Path                /dev/vg0/lv01
  LV Name                lv01
  VG Name                vg0
  LV UUID                UzEOmf-ko6J-N8NM-fbe0-l6Fe-VaJW-3sXTMx
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-06-14 20:41:05 +0800
  LV Status              available
  # open                 0
  LV Size                5.00 GiB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1

  --- Logical volume ---
  LV Path                /dev/vg0/lv02
  LV Name                lv02
  VG Name                vg0
  LV UUID                SiM4cn-PMjL-gpKJ-7e8I-ayox-yGrI-xGV04s
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-06-14 21:03:55 +0800
  LV Status              available
  # open                 0
  LV Size                5.00 GiB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:5

[root@localhost ~]# vg
vgcfgbackup      vgck             vgdisplay        vgimport         vgmerge          vgremove         vgscan
vgcfgrestore     vgconvert        vgexport         vgimportclone    vgmknodes        vgrename         vgsplit
vgchange         vgcreate         vgextend         vgimportdevices  vgreduce         vgs
[root@localhost ~]# man vgsplit
[root@localhost ~]# man vgsplit
[root@localhost ~]# vgsplit vg0 vg1 /dev/sda
  Logical volume vg0/lv02 must be inactive.

  #上述提示要先将lv02变为非激活状态，使用-an选项
[root@localhost ~]# lvchange -an /dev/vg0/lv02
[root@localhost ~]# lvdisplay
  --- Logical volume ---
  LV Path                /dev/rl/root
  LV Name                root
  VG Name                rl
  LV UUID                cchRZb-w3U5-s6Kh-mfLR-kr5a-TEvn-mGEe89
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-04-28 13:02:41 +0800
  LV Status              available
  # open                 1
  LV Size                20.00 GiB
  Current LE             5120
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

  --- Logical volume ---
  LV Path                /dev/vg0/lv01
  LV Name                lv01
  VG Name                vg0
  LV UUID                UzEOmf-ko6J-N8NM-fbe0-l6Fe-VaJW-3sXTMx
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-06-14 20:41:05 +0800
  LV Status              available
  # open                 0
  LV Size                5.00 GiB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1

  --- Logical volume ---
  LV Path                /dev/vg0/lv02
  LV Name                lv02
  VG Name                vg0
  LV UUID                SiM4cn-PMjL-gpKJ-7e8I-ayox-yGrI-xGV04s
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-06-14 21:03:55 +0800
  LV Status              NOT available
  LV Size                5.00 GiB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto

[root@localhost ~]# vgsplit vg0 vg1 /dev/sda
  New volume group "vg1" successfully split from "vg0"
[root@localhost ~]# vgs
  VG  #PV #LV #SN Attr   VSize   VFree
  rl    1   1   0 wz--n-  20.00g      0
  vg0   1   1   0 wz--n- <20.00g <15.00g
  vg1   1   1   0 wz--n- <20.00g <15.00g
[root@localhost ~]# lvs
  LV   VG  Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root rl  -wi-ao---- 20.00g
  lv01 vg0 -wi-a-----  5.00g
  lv02 vg1 -wi-------  5.00g
[root@localhost ~]# vgdisplay vg0
  --- Volume group ---
  VG Name               vg0
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  16
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               0
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               <20.00 GiB
  PE Size               4.00 MiB
  Total PE              5119
  Alloc PE / Size       1280 / 5.00 GiB
  Free  PE / Size       3839 / <15.00 GiB
  VG UUID               SuhDg9-pErc-NHtz-bWeM-m91R-nWRV-3CwEp4

[root@localhost ~]# vgdisplay -v vg0
  --- Volume group ---
  VG Name               vg0
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  16
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               0
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               <20.00 GiB
  PE Size               4.00 MiB
  Total PE              5119
  Alloc PE / Size       1280 / 5.00 GiB
  Free  PE / Size       3839 / <15.00 GiB
  VG UUID               SuhDg9-pErc-NHtz-bWeM-m91R-nWRV-3CwEp4

  --- Logical volume ---
  LV Path                /dev/vg0/lv01
  LV Name                lv01
  VG Name                vg0
  LV UUID                UzEOmf-ko6J-N8NM-fbe0-l6Fe-VaJW-3sXTMx
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-06-14 20:41:05 +0800
  LV Status              available
  # open                 0
  LV Size                5.00 GiB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1

  --- Physical volumes ---
  PV Name               /dev/sdb
  PV UUID               hpoGGr-cU1b-pb1g-MQwM-kVTT-ahdc-J0OOc2
  PV Status             allocatable
  Total PE / Free PE    5119 / 3839

[root@localhost ~]# vgdisplay -v vg1
  --- Volume group ---
  VG Name               vg1
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               0
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               <20.00 GiB
  PE Size               4.00 MiB
  Total PE              5119
  Alloc PE / Size       1280 / 5.00 GiB
  Free  PE / Size       3839 / <15.00 GiB
  VG UUID               poPXYZ-nSia-YmbF-Eg7p-it6u-X3bs-Ey6HVe

  --- Logical volume ---
  LV Path                /dev/vg1/lv02
  LV Name                lv02
  VG Name                vg1
  LV UUID                SiM4cn-PMjL-gpKJ-7e8I-ayox-yGrI-xGV04s
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2024-06-14 21:03:55 +0800
  LV Status              NOT available
  LV Size                5.00 GiB
  Current LE             1280
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto

  --- Physical volumes ---
  PV Name               /dev/sda
  PV UUID               y9gxEh-1IXq-C0Qx-EGLC-3iLu-qurH-YAlYhP
  PV Status             allocatable
  Total PE / Free PE    5119 / 3839

[root@localhost ~]# pvs
  PV             VG  Fmt  Attr PSize   PFree
  /dev/nvme0n1p2 rl  lvm2 a--   20.00g      0
  /dev/sda       vg1 lvm2 a--  <20.00g <15.00g
  /dev/sdb       vg0 lvm2 a--  <20.00g <15.00g

这时pv已经拆除，但问题是，如何将盘拔出？

  1. 如果直接拔出的话，pv层面会出问题，在pvs时会提示pv故障，逻辑卷丢失的情况：

  1. 也不可以pvremove，这样会把pv删除