===================================创建LVMVG扩展 / 缩小LV扩容

基本分区（ MBR | GPT ）-------> Filesustem ---------> mount逻辑卷LVM -------->Filesustem ---------> mount( 容错交给raid )PE：Physical extent 物理扩展 4M 8M 16M 32M 64M 创建VG时指定 -s 8MLE：Logical extent 逻辑扩展

一、创建LVM0.准备物理磁盘可以是 /dev/sdb /dev/sdc11.pvcreate、pvs、pvscan、pvdisplay、pvremovevgcreate....lvcreate......pvcreate /dev/sdcvgcreate datavg /dev/sdc//创建逻辑卷创建一个指定大小（100M）的lv，并指定名字为lv1 lv2lvcreate -L 100M -n lv1 datavglvcreate -l 25 -n lv2 datavg //PE默认为4M，增加25个PE2.创建文件系统并挂载[root@ecs-test-1 ~]# mkfs.ext4 /dev/datavg/lv1[root@ecs-test-1 ~]# mkfs.xfs /dev/datavg/lv2[root@ecs-test-1 ~]# vim /etc/fstab/dev/datavg/lv1 /mnt/lv1 ext4 defaults 0 0/dev/datavg/lv2 /mnt/lv2 xfs defaults 0 0[root@ecs-test-1 ~]# mount -a[root@ecs-test-1 ~]# df -h在线扩容 online二、VG管理1.扩大VG[root@localhost ~]# vgextend datavg /dev/sddPhysical volume "/dev/sdd" successfully created.Volume group "datavg" successfully extended正常流程应该是先将dev/sdd pvcreate 然后 vgextend 扩大2.缩小VG先做数据的迁移vgreduce datavg /dev/sde //将无数据的硬盘移除Removed "/dev/sde" from volume group "datavg"pvmove /dev/sdc //先将数据迁移再移除硬盘/dev/sdc: Moved: 30.00%/dev/sdc: Moved: 50.00%/dev/sdc: Moved: 100.00%vgreduce datavg /dev/sdc[root@localhost ~]# pvsPV VG Fmt Attr PSize PFree/dev/sda2 centos lvm2 a--