linuxPV,VG,LVm创建扩展缩减实现

系统运维 2023-07-16 Escape 手机阅读

lvm:logical volume Manager 版本号：lvm,lvm2 dm:device mapper 安全实现边界扩展功用：将一个或多个底块设备（包括RAID）组织成一个逻辑存储空间其边界：可动态扩展或缩减：

由三个层次组成，分别是PV,VG,LV 逻辑卷工作机制: PV刚被创建是没有PE的，只有PV加入vG以后才会确定PV上的PE有多大，每一个PV都会等分固定大小块的PE，由于这个快的大小是由VG决定的，所以，一个PV只有加入PV以后，PE才有固定大小，我们划分LV的时候，就是把Pe固定块大小组合起来形成一个存储空间，一旦PE被划分出来组织成LV，那他就叫做LE，所谓的逻辑盘，我们扩展逻辑盘的边界大小，就是通过PE来完成的。逻辑卷的大小是可以缩减的，通过LE的增加和缩减来完成，我们也可以称作PE。

lv,multipath

pe,le, pysical extent logical extent

管理lV pv:pvcreate,pvdisplay,pvs,pvscan,pvremove,pvmove

vg:vgcreate,vgdisplay,vgs,vgscan.vgremove,vgextend,vgreduce

lv:lvcreate,lvdisplay,lvs,lvresize,lvextend,lvreduce,lvremove

示例：创建一个4G VG： /dev/sdb4 397 6527 49247257+ 5 Extended /dev/sdb5 397 658 2104483+8e Linux LVM /dev/sdb6 659 920 2104483+ 8e Linux LVM [root@localhost ~]# partx -a /dev/sdb BLKPG: Device or resource busy error adding partition 1 BLKPG: Device or resource busy error adding partition 2 BLKPG: Device or resource busy error adding partition 3 BLKPG: Device or resource busy error adding partition 4 [root@localhost ~]#

[root@localhost ~]# pvcreate /dev/sdb[5,6] Physical volume "/dev/sdb5" successfully created Physical volume "/dev/sdb6" successfully created [root@localhost ~]# pvs PV VG Fmt Attr PSize PFree /dev/sdb5 lvm2 --- 2.01g 2.01g /dev/sdb6 lvm2 --- 2.01g 2.01g [root@localhost ~]# pvscan PV /dev/sdb5 lvm2 [2.01 GiB] PV /dev/sdb6 lvm2 [2.01 GiB] Total: 2 [4.01 GiB] / in use: 0 [0 ] / in no VG: 2 [4.01 GiB] [root@localhost ~]# pvdisplay （没有加入vg显示NEW Physical volume） "/dev/sdb5" is a new physical volume of "2.01 GiB" --- NEW Physical volume --- PV Name /dev/sdb5 VG Name PV Size 2.01 GiB Allocatable NO PE Size 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID u5YAZn-Rnuc-6lXW-TR2n-3Vzd-Aghq-7HDv73

"/dev/sdb6" is a new physical volume of "2.01 GiB" --- NEW Physical volume --- PV Name /dev/sdb6 VG Name PV Size 2.01 GiB Allocatable NO PE Size 0 Total PE 0（不属于vg是没有pe大小） Free PE 0 Allocated PE 0 PV UUID 2pZ50q-moJt-qWYn-4n8t-qi21-7QRV-e

vg：创建VG：新增一个VG，并指明其包含哪个或那些PV实现 1. vgcreate [dev/sd] -s 指明pe大小 -v 显示详细过程 -t 测试创建创建VG： [root@localhost ~]#vgcreate markvg /dev/sdb[5,6] Volume group "markvg" successfully created [root@localhost ~]# vgs VG #PV #LV #SN Attr VSize VFree markvg 2 0 0 wz--n- 4.01g 4.01g 查看变化 [root@localhost ~]#pvdisplay /dev/sdb5 --- Physical volume --- PV Name /dev/sdb5 VG Name markvg PV Size 2.01 GiB / not usable 3.16 MiB Allocatable yes PE Size 4.00 MiB Total PE 513 Free PE 513 Allocated PE 0 PV UUID u5YAZn-Rnuc-6lXW-TR2n-3Vzd-Aghq-7HDv73

[root@localhost ~]# [root@localhost ~]#vgdisplay --- Volume group --- VG Name markvg 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 4.01 GiB PE Size 4.00 MiB（pe默认大小为4M，也可以指定pe大小） Total PE 1026 Alloc PE / Size 0 / 0 Free PE / Size 1026 / 4.01 GiB VG UUID tfyfuD-h9Rn-EHbH-wU2J-5YuH-ItiJ-pqFtfo

[root@localhost ~]# 注意：这里的PE大小将会在缩减和扩展时以PE的大小递增创建16m的pe的vg vgcreate -s 16m markvg /dev/sdb[5,6]

缩减vg 1，挪走vg中的pv实现注意：计划移除的pv不能包含已经存储数据的pe，如果有需要先使用pvmove移动到同vg内其他pv上 pvmove /dev/sdv

删除pv pvremove /dev/sdb# 移除markvg [root@localhost ~]#vgreduce markvg /dev/sdb5 Removed "/dev/sdb5" from volume group "markvg" [root@localhost ~]# [root@localhost ~]#vgdisplay --- Volume group --- VG Name markvg System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 2 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 2.00 GiB PE Size 4.00 MiB Total PE 513 Alloc PE / Size 0 / 0 Free PE / Size 513 / 2.00 GiB VG UUID tfyfuD-h9Rn-EHbH-wU2J-5YuH-ItiJ-pqFtfo

[root@localhost ~]# 扩展vg：同vg中添加更多的pv实现 [root@localhost ~]#vgextend markvg /dev/sdb5 Volume group "markvg" successfully extended [root@localhost ~]#vgdisplay --- Volume group --- VG Name markvg System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 3 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 4.01 GiB PE Size 4.00 MiB Total PE 1026 Alloc PE / Size 0 / 0 Free PE / Size 1026 / 4.01 GiB VG UUID tfyfuD-h9Rn-EHbH-wU2J-5YuH-ItiJ-pqFtfo

[root@localhost ~]# 创建lv：logical volume lvcreate: lvcreate -l 多大[bskmgt] -n name vgname 注意：lv大小必须为pe的整数倍 [root@localhost ~]#lvcreate -L 2G -n name marklv markvg Volume group "marklv" not found [root@localhost ~]# [root@localhost ~]#lvdisplay --- Logical volume --- LV Path /dev/markvg/marklv LV Name marklv VG Name markvg LV UUID X2uIuJ-HU3J-rxp7-3Z0P-gnUq-1j8f-QP3w7k LV Write Access read/write LV Creation host, time localhost.localdomain, 2015-04-07 07:05:23 -0700 LV Status available 1. open 0 LV Size4.00 GiB Current LE 1024 Segments 2 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0 格式化，挂载使用 [root@localhost ~]# mke2fs -t ext4 /dev/markvg/marklv mke2fs 1.41.12 (17-May-2010) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 262144 inodes, 1048576 blocks 52428 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=1073741824 32 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736

Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 30 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. 挂载至/tmp/mark.raid0.1 [root@localhost ~]# mount /dev/markvg/marklv /tmp/mark.raid0.1/ [root@localhost ~]# ls /tmp/mark.raid0.1/ lost+found [root@localhost ~]# cp /etc/fstab /tmp/mark.raid0.1/ 查看 [root@localhost ~]#df Filesystem 1K-blocks Used Available Use% Mounted on /dev/sda2 121418860 2533528 112710868 3% / tmpfs 506144 72 506072 1% /dev/shm /dev/sda1 289293 28484 245449 11% /boot /dev/mapper/markvg-marklv 3997376 8192 3779472 1% /tmp/mark.raid0.1 [root@localhost ~]#

扩展lv: 存储设备有：物理边界文件系统有：逻辑边界

扩展：先扩展物理边界，而后拉伸逻辑编辑 lvextend ,lvresize resize2fs,

开始扩展：在挂载时，对markvg-marklv做扩展，来验证。目前是3997376 如何扩展lv条件：

1，先确定目标大小：确保此lv此在的vg中有足够的空闲可用 2，扩展物理边界 lvextend -l +/# /dev/vgname/lvname 3,拉伸逻辑边界 resize2fs /dev/vgname/lvname 使用vgdisplay查看空间

设备路径：[root@localhost ~]# lvdisplay /dev/markvg/marklv

设备路径： 1，/dev/vgname/lvname 2,/dev/mapper/vgname-lvname 实际路径：/dev/dm-# 移除lv(操作不可逆，和移除分区是一样): lvremove mylv路径 [root@localhost ~]# lvremove /dev/markvg/marklv Do you really want to remove active logical volume marklv? [y/n]: y Logical volume "marklv" successfully removed [root@localhost ~]#

如何扩展lv：

1，先确定目标大小：确保此lv此在的vg中有足够的空闲可用 2，扩展物理边界 lvextend -l +/# /dev/vgname/lvname 3,拉伸逻辑边界 resize2fs /dev/vgname/lvname

示例： vgdisplay myvg查看空间是否空闲 lvcreate -l +3g -n myvg 添加物理边界3g mke2fs -t ext4 /dev/myvg/mylv mount /dev/myvg/mylv

对mylv扩展格式化：resize2fs /dev/myvg/mylv 扩展到5G：[root@localhost ~]# lvextend -L 5G /dev/myvg/mylv 查看信息：[root@localhost ~]#lvs df -lh查看扩展后结果，而后拉伸在线拉伸逻辑分区：resize2fs /dev/myvg/mylv 以上命令为在线扩展在使用df -lh查看拉伸后结果

缩减lv；注意： 1，缩减要离线; 2，先缩减系统大小，在缩减lv的大小‘ 过程： 1，先确定缩减后的目标大小，要确保缩减后的大小能够容纳现在的所有数据 2，卸载逻辑卷，并强制做文件系统一致性检查 e2fsck -f /dev/myvg/mylv 3,开始缩减逻辑边界 resize2fs /dev/myvg/mylv #缩减大小 4，缩减物理边界 lvreduce -l [-] /dev/myvg/mylv

示例：

1，判断文件大小 du -sh 文件目标 2，umount 目标 3，e2fack -f /dev/myvg/mylv 4,resize2fs /dev/myvg/mylv 3g 5,lvreduce -l 3G /dev/myvg/mylv