LVM
LVM 磁碟管理
Learning
單個磁碟擴充未分割磁區
LVM Snapshot
常用指令
Logical Volume - LV
# 顯示所有 LV 使用狀況
lvdisplay -C
# 新增 LV
lvcreate -L 10G -n LV_name VG_name
# 刪除 LV
lvremove /dev/VG_name>/LV_name
# 更名 LV
lvrename /dev/VG-name/old-LV-name /dev/VG-name/new-LV-name
# 顯示 LV 狀況
lvs
lvs -a -o name,copy_percent,devices
lvs -a -o name,copy_percent,devices <vg-name>
lvs -a --segments -o +devices
# 擴充 LV 使用空間
lvextend -L +2G /dev/vg/lv
lvextend -l +100%FREE /dev/vg_db2v9/lv_root 將剩餘空間都加上
ext2online /dev/vg/lv (RHEL v4)
resize2fs /dev/vg/lv (RHEL v5,6)
xfs_growfs /dev/vg/lv (RHEL v7 with XFS filesystem)
# 縮小 LV 空間 (RHEL v4)
#說明:445GB -> 2GB
umount /worktmp
e2fsck -f /dev/rootVG/worktmpLV
resize2fs /dev/rootVG/worktmpLV 1843M
lvreduce -L 2GB /dev/rootVG/worktmpLV
resize2fs /dev/rootVG/worktmpLV
mount /worktmp
#註:1843MB 大約是要 2GB 的 90%,這裡的指令也能使用單位 GB
# Shrinking LV (RHEL 5/6)
#100 GB -> 5GB
umount /opt/oracle/arclog
resize2fs /dev/VolGroup00/arclogLV 5G
lvreduce -L 5G /dev/VolGroup00/arclogLV
e2fsck -f /dev/VolGroup00/arclogLV
mount /opt/oracle/arclog
Volume Group - VG
# 顯示 VG 使用狀況
vgdisplay -C
# 啟動/關閉 VG
vgchange -a y VG_name
vgchange -a n VG_name
#註:關閉後,執行 vgdisplay 仍會顯示,但 /dev/*** 已不存在。
# 新建 VG
vgcreate VG_name /dev/pv1 /dev/pv2
# 更名 VG
vgrename vg_esxa01db01 vg_root
# 刪除 VG
vgremove VG_name
# 增加 PV 到 VG
vgextend VG_name /dev/pv3
# 從 VG 中移除 PV
#NOTE: PV 必須沒有任何資料(檢查指令 pvs -o+pv_used)
vgreduce VG_name /dev/mypv
Physical Volume - PV
# 顯示 PV 使用狀況
pvdisplay -C
# 檢查所有 PV 的空間使用狀況
pvs -o+pv_used
# 新增 PV
pvcreate /dev/hdd1
# 刪除 PV
pvremove /dev/hdd1
# 如果整個 disk 都要作為 PV,該磁碟不能建立任何磁區,要清除舊磁區可以執行
dd if=/dev/zero of=/dev/sdd bs=512 count=1
# 既有的 LUN Disk 增加磁碟空間後,還需要執行
pvresize /dev/sd[X]
LVM 磁區的磁碟加大
在 RHEL 8 下,移除 LVM 磁區時,可能出現提示:
Do you want to remove the signature? [Y]es/[N]o:
注意: 這裡必須是 N,否則原有的磁區會被徹底清除。
技巧: 要確認 LVM 磁區是有完成延伸,或者不小心被移除,在 reboot 前執行
pvs
如果有顯示原有的 PV disk,表示磁區延伸成功。
Extend PV Disk: /dev/sda2 50GB to 100GB
[root@my-db2v11fp7 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 100G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 49G 0 part
├─rootvg-root 253:0 0 15G 0 lvm /
├─rootvg-swap 253:1 0 4G 0 lvm [SWAP]
└─rootvg-worktmp 253:2 0 512M 0 lvm /worktmp
sr0 11:0 1 1024M 0 rom
[root@my-db2v11fp7 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 rootvg lvm2 a-- <49.00g <29.50g
[root@my-db2v11fp7 ~]# fdisk -ul /dev/sda
Command (m for help): p
Disk /dev/sda: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000def6b
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 104857599 51379200 8e Linux LVM
Command (m for help): d
Partition number (1,2, default 2): 2
Partition 2 is deleted
Command (m for help): p
Disk /dev/sda: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000def6b
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
Command (m for help): n
Partition type:
p primary (1 primary, 0 extended, 3 free)
e extended
Select (default p): p
Partition number (2-4, default 2): 2
First sector (2099200-209715199, default 2099200):
Using default value 2099200
Last sector, +sectors or +size{K,M,G} (2099200-209715199, default 209715199):
Using default value 209715199
Partition 2 of type Linux and of size 99 GiB is set
Command (m for help): t
Partition number (1,2, default 2): 2
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): p
Disk /dev/sda: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000def6b
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 209715199 103808000 8e Linux LVM
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
[root@my-db2v11fp7 ~]# reboot
[root@my-db2v11fp7 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 100G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 99G 0 part
├─rootvg-root 253:0 0 15G 0 lvm /
├─rootvg-swap 253:1 0 4G 0 lvm [SWAP]
└─rootvg-worktmp 253:2 0 512M 0 lvm /worktmp
sr0 11:0 1 1024M 0 rom
[root@my-db2v11fp7 ~]# pvresize /dev/sda2
Physical volume "/dev/sda2" changed
1 physical volume(s) resized or updated / 0 physical volume(s) not resized
[root@my-db2v11fp7 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 rootvg lvm2 a-- <99.00g <79.50g
指令速查表
FAQ
無法新增 PV
Device /dev/sdj not found (or ignored by filtering).
Solution: 可能該磁碟有包含其他磁區
# fdisk -l /dev/sdj
WARNING: GPT (GUID Partition Table) detected on '/dev/sdj'! The util fdisk doesn't support GPT. Use GNU Parted.
Disk /dev/sdj: 3848.3 GB, 3848290697216 bytes
255 heads, 63 sectors/track, 467861 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdj1 1 267350 2147483647+ ee GPT
Partition 1 does not start on physical sector boundary.
移除這磁碟裡的所有磁區後再試一次。
移除已損壞的 PV
無法移除已經損壞 PV 的 VG 與 LV
有一個 PV - /dev/sdc 發生損毀,所屬 VG 與 LV 要移除時遇到錯誤:
Couldn't find device with uuid APgmaN-yCZG-WfQS-L5zm-vd6g-oEJc-WjzNrT.
Can't remove locked LV isths_DMSCouldn't find device with uuid APgmaN-yCZG-WfQS-L5zm-vd6g-oEJc-WjzNrT.
WARNING: Partial LV isths_home needs to be repaired or removed.
WARNING: Partial LV isths_DMS needs to be repaired or removed.
WARNING: Partial LV pvmove0 needs to be repaired or removed.
There are still partial LVs in VG vg_db.
To remove them unconditionally use: vgreduce --removemissing --force.
Proceeding to remove empty missing PVs.
Solution: VG Name: vg_db
# vgcfgbackup vg_db
Couldn't find device with uuid APgmaN-yCZG-WfQS-L5zm-vd6g-oEJc-WjzNrT.
Volume group "vg_db" successfully backed up.
/etc/lvm/backup/vg_db:
...
logical_volumes {
...
...
}
...
將段落 logical_volumes 整個移除。
執行 vgcfgrestore
# vgcfgrestore vg_db
Restored volume group vg_db
重新掃描再重新執行移除 LV 與 VG
pvs
vgs
lvs
vgremove vg_db
USB 掛載包含有 LVM 的硬碟,出現錯誤訊息
# mount -t ext3 /dev/VolGroup00/LogVol00 /mnt/lvm00
mount: wrong fs type, bad option, bad superblock on /dev/mapper/VolGroup00-LogVol00,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
Solution:
vgchange -an VolGroup00
vgchange -ay VolGroup00
mount -t ext3 /dev/VolGroup00/LogVol00 /mnt/lvm00
無法新增 LV
系統剛安裝完,執行 pvdisplay -C 出現錯誤,並且無法新增 LV
Couldn't find device with uuid ZrneWS-8KHd-UiXV-rQ4q-YU0o-r9Ga-0ZVBPW
Solution: 這個硬碟可能曾經做過 LVM 格式化,這些是之前遺留的裝置名稱,要清除這些不存在的舊設定。
# vgreduce -removemissing <vg-name>
TIPs:
要查出這些不存在的 device 的所屬 VG,可以執行 pvdisplay 。
建立 GPT 磁區
With parted
# parted /dev/vdb
GNU Parted 3.4
Using /dev/vdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel GPT
(parted) mkpart primary 2048s 100%
(parted) q
Information: You may need to update /etc/fstab.
進階應用
VG Import/Export
VG 移轉至不同的主機
移除 PV Disk
從一個現有 LV 中移除正在使用的一個 PV Disk (/dev/sdb1)
NOTE: 這個 LV 的所屬 VG 必須要有足夠的可用空間
# pvs -o+pv_used
PV VG Fmt Attr PSize PFree Used
/dev/sda1 myvg lvm2 a- 17.15G 12.15G 5.00G
/dev/sdb1 myvg lvm2 a- 17.15G 12.15G 5.00G
/dev/sdc1 myvg lvm2 a- 17.15G 12.15G 5.00G
/dev/sdd1 myvg lvm2 a- 17.15G 2.15G 15.00G
# pvremove /dev/sdb1
/dev/sdb1: Moved: 2.0%
...
/dev/sdb1: Moved: 79.2%
...
/dev/sdb1: Moved: 100.0%
# pvs -o+pv_used
PV VG Fmt Attr PSize PFree Used
/dev/sda1 myvg lvm2 a- 17.15G 7.15G 10.00G
/dev/sdb1 myvg lvm2 a- 17.15G 17.15G 0
/dev/sdc1 myvg lvm2 a- 17.15G 12.15G 5.00G
/dev/sdd1 myvg lvm2 a- 17.15G 2.15G 15.00G
# vgreduce myvg /dev/sdb1
Removed "/dev/sdb1" from volume group "myvg"
[root@tng3-1 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda1 myvg lvm2 a- 17.15G 7.15G
/dev/sdb1 lvm2 -- 17.15G 17.15G
/dev/sdc1 myvg lvm2 a- 17.15G 12.15G
/dev/sdd1 myvg lvm2 a- 17.15G 2.15G
搬移 PV Disk
搬移現有 PV Disk (/dev/sdb1) 內的所有資料至一個新的 PV Disk (/dev/sdd1)
方法一:使用 Mirror 方式 *建議*
參考連結:
- https://www.thegeekdiary.com/centos-rhel-7-how-to-create-and-remove-the-lvm-mirrors-using-lvconvert/
- https://linux.m2osw.com/creating-drive-mirror-lvm-including-exact-partition-cloning
說明:
- VG: vg_data
- LV: db_worktmp, lv_mydev, lv_worktmp
- PV: from /dev/sdb1 to /dev/sdc
1. 確認新硬碟的容量需求
#> lvs -a -o name,copy_percent,devices,lv_size vg_data
LV Cpy%Sync Devices LSize
db_worktmp /dev/sdb1(0) 20.00g
lv_mydev /dev/sdb1(5121) 60.00g
lv_mydev /dev/sdb1(10242) 60.00g
lv_worktmp /dev/sdb1(20482) 500.00m
2. 將新硬碟加入到同一個 VG 內
#> vgextend vg_data /dev/sdc
3. 逐一將所有 LV 作完 Mirror
#> lvconvert -m1 vg_data/db_worktmp
#> lvconvert -m1 vg_data/lv_mydev
#> lvconvert -m1 vg_data/lv_worktmp
檢查 Mirror 時的進度
#> lvs -a -o name,copy_percent,devices,lv_size vg_data
4. 逐一將所有 LV 移除 Mirror,需指定舊硬碟代號
#> lvconvert -m0 vg_data/db_worktmp /dev/sdb1
#> lvconvert -m0 vg_data/lv_mydev /dev/sdb1
#> lvconvert -m0 vg_data/lv_worktmp /dev/sdb1
5. 從 VG 裡移除 PV /dev/sdb1, 再移除整個 PV
#> vgreduce vg_data /dev/sdb1
#> pvremove /dev/sdb1
方法二:使用 PV 搬移指令 pvmove
NOTE: PV 必須在同一個 VG 才能互相搬移
# pvs -o+pv_used
PV VG Fmt Attr PSize PFree Used
/dev/sda1 myvg lvm2 a- 17.15G 7.15G 10.00G
/dev/sdb1 myvg lvm2 a- 17.15G 15.15G 2.00G
/dev/sdc1 myvg lvm2 a- 17.15G 15.15G 2.00G
# pvcreate /dev/sdd1
Physical volume "/dev/sdd1" successfully created
# vgextend myvg /dev/sdd1
Volume group "myvg" successfully extended
[root@tng3-1]# pvs -o+pv_used
PV VG Fmt Attr PSize PFree Used
/dev/sda1 myvg lvm2 a- 17.15G 7.15G 10.00G
/dev/sdb1 myvg lvm2 a- 17.15G 15.15G 2.00G
/dev/sdc1 myvg lvm2 a- 17.15G 15.15G 2.00G
/dev/sdd1 myvg lvm2 a- 17.15G 17.15G 0
# pvmove /dev/sdb1 /dev/sdd1
/dev/sdb1: Moved: 10.0%
...
/dev/sdb1: Moved: 79.7%
...
/dev/sdb1: Moved: 100.0%
[root@tng3-1]# pvs -o+pv_used
PV VG Fmt Attr PSize PFree Used
/dev/sda1 myvg lvm2 a- 17.15G 7.15G 10.00G
/dev/sdb1 myvg lvm2 a- 17.15G 17.15G 0
/dev/sdc1 myvg lvm2 a- 17.15G 15.15G 2.00G
/dev/sdd1 myvg lvm2 a- 17.15G 15.15G 2.00G
# vgreduce myvg /dev/sdb1
Removed "/dev/sdb1" from volume group "myvg"
Filesystems
Linux Filesystem Comparison