22,lvm 数据迁移

lvm 数据迁移：
	使用fdisk结合partprobe命令不重启系统添加 一块新的磁盘分区。
[root@centos7 app]# lsblk 
NAME             MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                8:0    0   10G  0 disk 
├─sda1             8:1    0  200M  0 part /boot
└─sda2             8:2    0  9.8G  0 part 
  ├─centos-root  253:0    0  9.3G  0 lvm  /
  └─centos-swap  253:1    0  512M  0 lvm  [SWAP]
sdb                8:16   0    3G  0 disk 
├─sdb1             8:17   0  512B  0 part 
├─sdb5             8:21   0  500M  0 part 
│ └─vg1_demo-lv1 253:2    0   84M  0 lvm  /app
├─sdb6             8:22   0   50M  0 part 
└─sdb7             8:23   0   50M  0 part 
sr0               11:0    1 1024M  0 rom  
[root@centos7 app]# 
[root@centos7 app]# partprobe /dev/sdb
[root@centos7 app]# 
[root@centos7 app]# lsblk 
NAME             MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                8:0    0   10G  0 disk 
├─sda1             8:1    0  200M  0 part /boot
└─sda2             8:2    0  9.8G  0 part 
  ├─centos-root  253:0    0  9.3G  0 lvm  /
  └─centos-swap  253:1    0  512M  0 lvm  [SWAP]
sdb                8:16   0    3G  0 disk 
├─sdb1             8:17   0  512B  0 part 
├─sdb5             8:21   0  500M  0 part 
│ └─vg1_demo-lv1 253:2    0   84M  0 lvm  /app
├─sdb6             8:22   0   50M  0 part 
├─sdb7             8:23   0   50M  0 part 
└─sdb8             8:24   0  2.4G  0 part 
sr0               11:0    1 1024M  0 rom  
[root@centos7 app]# 




第一步：将创建新的pv，将它加入到vg
[root@centos7 app]# pvcreate /dev/sdb8
[root@centos7 ~]# pvs
[root@centos7 ~]# 
[root@centos7 ~]# 
[root@centos7 ~]# vgextend vg1_demo /dev/sdb8
  Volume group "vg1_demo" successfully extended
[root@centos7 ~]# 

第二步：将数据由  /dev/sdb5 迁移到  /dev/sdb8
[root@centos7 app]# pvs
  PV         VG       Fmt  Attr PSize   PFree  
  /dev/sda2  centos   lvm2 a--    9.80g      0 
  /dev/sdb5  vg1_demo lvm2 a--  496.00m 412.00m
  /dev/sdb6  vg1_demo lvm2 a--   48.00m  48.00m
  /dev/sdb7  vg1_demo lvm2 a--   48.00m  48.00m
  /dev/sdb8  vg1_demo lvm2 a--   <2.41g  <2.41g
[root@centos7 app]# 
[root@centos7 app]# 
[root@centos7 app]# pvmove /dev/sdb5 /dev/sdb8
  /dev/sdb5: Moved: 66.67%
[root@centos7 app]# 

第三步：将  /dev/sdb5 从vg内移除
[root@centos7 app]# vgreduce vg1_demo /dev/sdb5
  Removed "/dev/sdb5" from volume group "vg1_demo"
[root@centos7 app]# 

第四步：将pv的标记删除
[root@centos7 app]# pvs
  PV         VG       Fmt  Attr PSize   PFree  
  /dev/sda2  centos   lvm2 a--    9.80g      0 
  /dev/sdb5           lvm2 ---  500.00m 500.00m
  /dev/sdb6  vg1_demo lvm2 a--   48.00m  48.00m
  /dev/sdb7  vg1_demo lvm2 a--   48.00m  48.00m
  /dev/sdb8  vg1_demo lvm2 a--   <2.41g   2.32g
[root@centos7 app]# 
[root@centos7 app]# 
[root@centos7 app]# pvremove /dev/sdb5
  Labels on physical volume "/dev/sdb5" successfully wiped.
[root@centos7 app]# 
[root@centos7 app]# pvs
  PV         VG       Fmt  Attr PSize  PFree 
  /dev/sda2  centos   lvm2 a--   9.80g     0 
  /dev/sdb6  vg1_demo lvm2 a--  48.00m 48.00m
  /dev/sdb7  vg1_demo lvm2 a--  48.00m 48.00m
  /dev/sdb8  vg1_demo lvm2 a--  <2.41g  2.32g
[root@centos7 app]# 



删除LVM:
lvremove
vgremove
pvremove


LV 缩小：
[root@centos7 app]# df -h
/dev/mapper/vg1_demo-lv1   78M   25M   49M  34% /app
[root@centos7 app]# 
[root@centos7 app]# 
[root@centos7 app]# umount /app/
[root@centos7 app]# resize2fs /dev/mapper/vg1_demo-lv1 50M
[root@centos7 app]# e2fsck -f /dev/mapper/vg1_demo-lv1
[root@centos7 app]# resize2fs /dev/mapper/vg1_demo-lv1 50M
[root@centos7 app]# lvreduce -L 50M /dev/mapper/vg1_demo-lv1
[root@centos7 app]# mount /dev/mapper/vg1_demo-lv1 /app