逻辑卷管理器-缩减
0、背景：两块物理硬盘组成逻辑卷，由于硬盘故障或硬盘迁移等原因，需从卷组中移除硬盘，要先针对逻辑卷（testlv）进行缩减。
[root@localhost testdir]# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 475M 0 475M 0% /dev tmpfs 487M 0 487M 0% /dev/shm tmpfs 487M 7.7M 479M 2% /run tmpfs 487M 0 487M 0% /sys/fs/cgroup /dev/mapper/centos-root 25G 1.9G 24G 8% / /dev/sda1 497M 130M 367M 27% /boot /dev/mapper/bsoftvg-data 21G 33M 21G 1% /data tmpfs 98M 0 98M 0% /run/user/0 /dev/mapper/testvg-testlv 40G 17G 24G 43% /testdir
[root@localhost testdir]# blkid /dev/sda1: UUID="dbe36a10-9cce-47c8-a5f1-a6a5245665e5" TYPE="xfs" /dev/sda2: UUID="G4T07B-KCn3-oGuc-diPV-nQks-MyfT-0E8Rfp" TYPE="LVM2_member" /dev/sda3: UUID="kL2FKX-f0QQ-iKnX-GKsW-U9Pg-7z3e-ExoWqK" TYPE="LVM2_member" /dev/mapper/centos-root: UUID="e493b776-83fe-43d6-aaed-2c4ccc6af3fc" TYPE="xfs" /dev/mapper/centos-swap: UUID="2153499d-e627-4380-9beb-14a8c0abf6c6" TYPE="swap" /dev/mapper/bsoftvg-data: UUID="34a18630-78ea-4deb-88b7-9bf600a8cc54" TYPE="xfs" /dev/sdb: UUID="IjBHLs-oojg-y4v3-E50L-vgUO-lSBb-eed6zr" TYPE="LVM2_member" /dev/mapper/testvg-testlv: UUID="57f1b978-585b-40a7-a08f-0a7b43863add" TYPE="xfs" /dev/sdc: UUID="sOhp6w-fchC-ZMRt-s188-esE0-tPc4-i37gtb" TYPE="LVM2_member"
1、取消挂载
umount /testdir/
遇到取消挂载不成功的情况，退出bash，重新登录。
[root@localhost testdir]# umount /testdir/
umount: /testdir: target is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
[root@localhost testdir]#
[root@localhost testdir]#
[root@localhost testdir]#
[root@localhost testdir]# lsof | grep /test
bash 1321 root cwd DIR 253,3 198 64 /testdir
lsof 1569 root cwd DIR 253,3 198 64 /testdir
grep 1570 root cwd DIR 253,3 198 64 /testdir
lsof 1571 root cwd DIR 253,3 198 64 /testdir
[root@localhost testdir]# exit
logout
[root@localhost ~]# umount /testdir/ [root@localhost ~]# [root@localhost ~]# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 475M 0 475M 0% /dev tmpfs 487M 0 487M 0% /dev/shm tmpfs 487M 7.7M 479M 2% /run tmpfs 487M 0 487M 0% /sys/fs/cgroup /dev/mapper/centos-root 25G 1.9G 24G 8% / /dev/sda1 497M 130M 367M 27% /boot /dev/mapper/bsoftvg-data 21G 33M 21G 1% /data tmpfs 98M 0 98M 0% /run/user/0
2、缩减逻辑卷到18G
lvreduce -L 18G /dev/testvg/testlv
[root@localhost ~]# lvreduce -L 18G /dev/testvg/testlv WARNING: Reducing active logical volume to 18.00 GiB. THIS MAY DESTROY YOUR DATA (filesystem etc.) Do you really want to reduce testvg/testlv? [y/n]: y Size of logical volume testvg/testlv changed from 39.99 GiB (10238 extents) to 18.00 GiB (4608 extents). Logical volume testvg/testlv successfully resized.
提示：缩减逻辑卷会破坏数据、文件系统等，需要提前进行数据备份。
缩减lv后，pv、gv均多了空闲空间
[root@localhost ~]# pvs PV VG Fmt Attr PSize PFree /dev/sda2 centos lvm2 a-- 29.00g 4.00m /dev/sda3 bsoftvg lvm2 a-- 20.50g 0 /dev/sdb testvg lvm2 a-- <20.00g <2.00g /dev/sdc testvg lvm2 a-- <20.00g <20.00g [root@localhost ~]# vgs VG #PV #LV #SN Attr VSize VFree bsoftvg 1 1 0 wz--n- 20.50g 0 centos 1 2 0 wz--n- 29.00g 4.00m testvg 2 1 0 wz--n- 39.99g 21.99g [root@localhost ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert data bsoftvg -wi-ao---- 20.50g root centos -wi-ao---- 25.00g swap centos -wi-ao---- 4.00g testlv testvg -wi-a----- 18.00g
3、取消激活要移除的硬盘
pvchange -xn /dev/sdc
[root@localhost ~]# pvchange -xn /dev/sdc Physical volume "/dev/sdc" changed 1 physical volume changed / 0 physical volumes not changed [root@localhost ~]#pvdisplay
4、从vg中移除硬盘
vgreduce testvg /dev/sdc
[root@localhost ~]# vgreduce testvg /dev/sdc Removed "/dev/sdc" from volume group "testvg" [root@localhost ~]# [root@localhost ~]# [root@localhost ~]# [root@localhost ~]# vgs VG #PV #LV #SN Attr VSize VFree bsoftvg 1 1 0 wz--n- 20.50g 0 centos 1 2 0 wz--n- 29.00g 4.00m testvg 1 1 0 wz--n- <20.00g <2.00g [root@localhost ~]# [root@localhost ~]# pvs PV VG Fmt Attr PSize PFree /dev/sda2 centos lvm2 a-- 29.00g 4.00m /dev/sda3 bsoftvg lvm2 a-- 20.50g 0 /dev/sdb testvg lvm2 a-- <20.00g <2.00g /dev/sdc lvm2 --- 20.00g 20.00g
5、移除物理卷，此时可以拔出硬盘
pvremove /dev/sdc
[root@localhost ~]# pvremove /dev/sdc Labels on physical volume "/dev/sdc" successfully wiped. [root@localhost ~]# [root@localhost ~]# [root@localhost ~]# pvs PV VG Fmt Attr PSize PFree /dev/sda2 centos lvm2 a-- 29.00g 4.00m /dev/sda3 bsoftvg lvm2 a-- 20.50g 0 /dev/sdb testvg lvm2 a-- <20.00g <2.00g
6、对缩减的卷组进行格式化
mkfs.xfs /dev/testvg/testlv
[root@localhost ~]# mkfs.xfs -f /dev/testvg/testlv
meta-data=/dev/testvg/testlv isize=512 agcount=4, agsize=1179648 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=4718592, 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
7、格式化lv会生成新的UUID，需要更新fstab文件，并重新加载：mount -a
[root@localhost ~]# blkid /dev/sda1: UUID="dbe36a10-9cce-47c8-a5f1-a6a5245665e5" TYPE="xfs" /dev/sda2: UUID="G4T07B-KCn3-oGuc-diPV-nQks-MyfT-0E8Rfp" TYPE="LVM2_member" /dev/sda3: UUID="kL2FKX-f0QQ-iKnX-GKsW-U9Pg-7z3e-ExoWqK" TYPE="LVM2_member" /dev/mapper/centos-root: UUID="e493b776-83fe-43d6-aaed-2c4ccc6af3fc" TYPE="xfs" /dev/mapper/centos-swap: UUID="2153499d-e627-4380-9beb-14a8c0abf6c6" TYPE="swap" /dev/mapper/bsoftvg-data: UUID="34a18630-78ea-4deb-88b7-9bf600a8cc54" TYPE="xfs" /dev/sdb: UUID="IjBHLs-oojg-y4v3-E50L-vgUO-lSBb-eed6zr" TYPE="LVM2_member" /dev/mapper/testvg-testlv: UUID="f4546708-5e38-45a7-8894-d8f6057182dc" TYPE="xfs" /dev/sdc: UUID="sOhp6w-fchC-ZMRt-s188-esE0-tPc4-i37gtb" TYPE="LVM2_member"
vim /etc/fstab
# /etc/fstab # Created by anaconda on Mon Feb 21 10:59:48 2022 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # /dev/mapper/centos-root / xfs defaults 0 0 UUID=dbe36a10-9cce-47c8-a5f1-a6a5245665e5 /boot xfs defaults 0 0 /dev/mapper/centos-swap swap swap defaults 0 0 UUID=34a18630-78ea-4deb-88b7-9bf600a8cc54 /data xfs defaults 0 0 UUID=f4546708-5e38-45a7-8894-d8f6057182dc /testdir xfs defaults 0 0
[root@localhost ~]# mount -a [root@localhost ~]# [root@localhost ~]# df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 475M 0 475M 0% /dev tmpfs 487M 0 487M 0% /dev/shm tmpfs 487M 7.7M 479M 2% /run tmpfs 487M 0 487M 0% /sys/fs/cgroup /dev/mapper/centos-root 25G 1.9G 24G 8% / /dev/sda1 497M 130M 367M 27% /boot /dev/mapper/bsoftvg-data 21G 33M 21G 1% /data /dev/mapper/testvg-testlv 18G 33M 18G 1% /testdir tmpfs 98M 0 98M 0% /run/user/0
