LVM 檔案系統管理

Q: 無法新增 PV

Device /dev/sdj not found (or ignored by filtering).

Ans: 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。

Q: 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 要移除重建時遇到錯誤：

Couldn't find device with uuid APgmaN-yCZG-WfQS-L5zm-vd6g-oEJc-WjzNrT.
Can't remove locked LV isths_DMS

  Couldn'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.

解決方案：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.

# vi /etc/lvm/backup/vg_db 

/etc/lvm/backup/vg_db:

...
logical_volumes {
...
...
}
... 

將段落 logical_volumes 整個移除。

# 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

Q: 使用 USB 掛載包含有 LVM 的硬碟，出現錯誤訊息

fax:~# 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

解決：

# vgchange -an VolGroup00
# vgchange -ay VolGroup00
# mount -t ext3 /dev/VolGroup00/LogVol00 /mnt/lvm00

Q: 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

• https://access.redhat.com/site/docum...disk_remove_ex
• http://www.tecmint.com/lvm-storage-migration/

# 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

# pvmove /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

Q: 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*

• 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 Mirrir

#> 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 

參考連結：

• https://www.thegeekdiary.com/centos-...ing-lvconvert/
• https://linux.m2osw.com/creating-dri...tition-cloning

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"

Q: LV Mirror

• Recovering from LVM Mirror Failure
• Cloning Logical Volume using LVM
• How to Create and Remove the LVM Mirrors Using lvconvert

Q: 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

Ans：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，執行

# vgreduce -removemissing <vg-name>

TIPs：

要查出這些不存在的 device 的所屬 VG，可以執行 pvdisplay 。