LVM簡易メモ
今まであまり手を出してこなかったので、LVMを少し触ってみる事にしました。
自分自身の備忘録としてまとめておきます。
LVM
なんだかんだでWikipediaの記述をメモ
wikipedia:論理ボリュームマネージャ
触りだす
まずはディスクの状況。
# df -k
Filesystem 1K-ブロック 使用 使用可 使用% マウント位置
/dev/mapper/VolGroup00-LogVol00
5713496 1069312 4349272 20% /
/dev/sda1 101086 12181 83686 13% /boot
tmpfs 127708 0 127708 0% /dev/shm
# fdisk /dev/sda
コマンド (m でヘルプ): p
Disk /dev/sda: 6442 MB, 6442450944 bytes
255 heads, 63 sectors/track, 783 cylinders
Units = シリンダ数 of 16065 * 512 = 8225280 bytes
デバイス Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 783 6185025 8e Linux LVM
コマンド (m でヘルプ): q
# fdisk /dev/sdb
コマンド (m でヘルプ): p
Disk /dev/sdb: 6442 MB, 6442450944 bytes
255 heads, 63 sectors/track, 783 cylinders
Units = シリンダ数 of 16065 * 512 = 8225280 bytes
デバイス Boot Start End Blocks Id System
コマンド (m でヘルプ): q
今の状態を「pvdisplay」「vgdisplay」「lvdisplay」コマンドで確認
# pvdisplay --- Physical volume --- PV Name /dev/sda2 VG Name VolGroup00 PV Size 5.90 GB / not usable 24.06 MB Allocatable yes (but full) PE Size (KByte) 32768 Total PE 188 Free PE 0 Allocated PE 188 PV UUID 5imoca-Vjqo-o0T7-nps3-FSFg-bq5W-fRDAMO # vgdisplay --- Volume group --- VG Name VolGroup00 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 3 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 5.88 GB PE Size 32.00 MB Total PE 188 Alloc PE / Size 188 / 5.88 GB Free PE / Size 0 / 0 VG UUID YosyTo-mMb5-EuRk-QmrS-zaxA-vPKw-0pyUdQ # lvdisplay --- Logical volume --- LV Name /dev/VolGroup00/LogVol00 VG Name VolGroup00 LV UUID 2kFcxN-1XnZ-CAe3-hCSM-ocbA-3H2i-s8zISL LV Write Access read/write LV Status available # open 1 LV Size 5.62 GB Current LE 180 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:0 --- Logical volume --- LV Name /dev/VolGroup00/LogVol01 VG Name VolGroup00 LV UUID qZpPrE-SBGQ-NU4W-rVQ0-H2KI-Iy1A-crh112 LV Write Access read/write LV Status available # open 1 LV Size 256.00 MB Current LE 8 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:1
PVを作成しておく
準備という事で、「/dev/sdb」を利用。
# fdisk -l /dev/sdb
Disk /dev/sdb: 6442 MB, 6442450944 bytes
255 heads, 63 sectors/track, 783 cylinders
Units = シリンダ数 of 16065 * 512 = 8225280 bytes
デバイス Boot Start End Blocks Id System
/dev/sdb1 1 400 3212968+ 83 Linux
/dev/sdb2 401 783 3076447+ 83 Linux
# pvcreate -v /dev/sdb1 /dev/sdb2
Wiping cache of LVM-capable devices
Set up physical volume for "/dev/sdb1" with 6425937 available sectors
Zeroing start of device /dev/sdb1
Physical volume "/dev/sdb1" successfully created
Set up physical volume for "/dev/sdb2" with 6152895 available sectors
Zeroing start of device /dev/sdb2
Physical volume "/dev/sdb2" successfully created
VGにパーティションを追加する
すでに存在するVG「VolGroup00」に「/dev/sdb1」を追加してみます。
「vgextend」コマンドで対象を指定すればOKです。
# vgdisplay --- Volume group --- VG Name VolGroup00 System ID Format lvm2 Metadata Areas 1 Metadata Sequence No 3 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 1 Act PV 1 VG Size 5.88 GB PE Size 32.00 MB Total PE 188 Alloc PE / Size 188 / 5.88 GB Free PE / Size 0 / 0 VG UUID YosyTo-mMb5-EuRk-QmrS-zaxA-vPKw-0pyUdQ # vgextend VolGroup00 /dev/sdb1 Volume group "VolGroup00" successfully extended # vgdisplay --- Volume group --- VG Name VolGroup00 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 4 VG Access read/write VG Status resizable MAX LV 0 Cur LV 2 Open LV 2 Max PV 0 Cur PV 2 Act PV 2 VG Size 8.94 GB PE Size 32.00 MB Total PE 286 Alloc PE / Size 188 / 5.88 GB Free PE / Size 98 / 3.06 GB VG UUID YosyTo-mMb5-EuRk-QmrS-zaxA-vPKw-0pyUdQ
LVを拡張する
ということで拡張します。「lvextend」コマンドで容量を指定して、
「resize2fs」コマンドで領域を拡張します。
# df -k
Filesystem 1K-ブロック 使用 使用可 使用% マウント位置
/dev/mapper/VolGroup00-LogVol00
5713496 1069404 4349180 20% /
/dev/sda1 101086 12181 83686 13% /boot
tmpfs 127708 0 127708 0% /dev/shm
# lvextend -l+50 /dev/VolGroup00/LogVol00
Extending logical volume LogVol00 to 7.19 GB
Logical volume LogVol00 successfully resized
# resize2fs /dev/VolGroup00/LogVol00
resize2fs 1.39 (29-May-2006)
Filesystem at /dev/VolGroup00/LogVol00 is mounted on /; on-line resizing required
Performing an on-line resize of /dev/VolGroup00/LogVol00 to 1884160 (4k) blocks.
The filesystem on /dev/VolGroup00/LogVol00 is now 1884160 blocks long.
# df -k
Filesystem 1K-ブロック 使用 使用可 使用% マウント位置
/dev/mapper/VolGroup00-LogVol00
7298536 1070844 5850880 16% /
/dev/sda1 101086 12181 83686 13% /boot
tmpfs 127708 0 127708 0% /dev/shm
無事拡張できました。
PV移動とVGの取り外し
一旦先ほど作っておいた「/dev/sdb2」をVGに追加します。
今度は「/dev/sdb1」を取り外します。
# pvmove -v /dev/sdb1 Finding volume group "VolGroup00"
Archiving volume group "VolGroup00" metadata (seqno 12).
Creating logical volume pvmove0
Moving 50 extents of logical volume VolGroup00/LogVol00
Found volume group "VolGroup00"
activation/volume_list configuration setting not defined, checking only host tags for VolGroup00/LogVol00
Updating volume group metadata
Found volume group "VolGroup00"
Found volume group "VolGroup00"
Suspending VolGroup00-LogVol00 (253:0) with device flush
Found volume group "VolGroup00"
activation/volume_list configuration setting not defined, checking only host tags for VolGroup00/pvmove0
Creating VolGroup00-pvmove0
Loading VolGroup00-pvmove0 table (253:2)
Resuming VolGroup00-pvmove0 (253:2)
Found volume group "VolGroup00"
Loading VolGroup00-pvmove0 table (253:2)
Suppressed VolGroup00-pvmove0 identical table reload.
Loading VolGroup00-LogVol00 table (253:0)
Resuming VolGroup00-LogVol00 (253:0)
Creating volume group backup "/etc/lvm/backup/VolGroup00" (seqno 13).
Checking progress before waiting every 15 seconds
/dev/sdb1: Moved: 0.0%
/dev/sdb1: Moved: 12.0%
/dev/sdb1: Moved: 24.0%
/dev/sdb1: Moved: 30.0%
/dev/sdb1: Moved: 38.0%
/dev/sdb1: Moved: 52.0%
/dev/sdb1: Moved: 74.0%
/dev/sdb1: Moved: 100.0%
Found volume group "VolGroup00"
Found volume group "VolGroup00"
Loading VolGroup00-LogVol00 table (253:0)
Suspending VolGroup00-LogVol00 (253:0) with device flush
Suspending VolGroup00-pvmove0 (253:2) with device flush
Found volume group "VolGroup00"
Found volume group "VolGroup00"
Found volume group "VolGroup00"
Resuming VolGroup00-pvmove0 (253:2)
Found volume group "VolGroup00"
Resuming VolGroup00-LogVol00 (253:0)
Found volume group "VolGroup00"
Removing VolGroup00-pvmove0 (253:2)
Found volume group "VolGroup00"
Removing temporary pvmove LV
Writing out final volume group after pvmove
Creating volume group backup "/etc/lvm/backup/VolGroup00" (seqno 15).
# vgdisplay -v
Finding all volume groups
Finding volume group "VolGroup00"
--- Volume group ---
VG Name VolGroup00
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 15
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 3
Act PV 3
VG Size 11.84 GB
PE Size 32.00 MB
Total PE 379
Alloc PE / Size 238 / 7.44 GB
Free PE / Size 141 / 4.41 GB
VG UUID YosyTo-mMb5-EuRk-QmrS-zaxA-vPKw-0pyUdQ
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID 2kFcxN-1XnZ-CAe3-hCSM-ocbA-3H2i-s8zISL
LV Write Access read/write
LV Status available
# open 1
LV Size 7.19 GB
Current LE 230
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol01
VG Name VolGroup00
LV UUID qZpPrE-SBGQ-NU4W-rVQ0-H2KI-Iy1A-crh112
LV Write Access read/write
LV Status available
# open 1
LV Size 256.00 MB
Current LE 8
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
--- Physical volumes ---
PV Name /dev/sda2
PV UUID 5imoca-Vjqo-o0T7-nps3-FSFg-bq5W-fRDAMO
PV Status allocatable
Total PE / Free PE 188 / 0
PV Name /dev/sdb1
PV UUID bj7HVH-0JIb-zp9t-7IKH-H22C-RXDl-9nV6HS
PV Status allocatable
Total PE / Free PE 98 / 98
PV Name /dev/sdb2
PV UUID ARSOIX-7g90-OJpK-wyy8-rKEP-y0yH-oZWpn7
PV Status allocatable
Total PE / Free PE 93 / 43
# vgreduce -v VolGroup00 /dev/sdb1 Finding volume group "VolGroup00"
Using physical volume(s) on command line
Archiving volume group "VolGroup00" metadata (seqno 15).
Removing "/dev/sdb1" from volume group "VolGroup00"
Creating volume group backup "/etc/lvm/backup/VolGroup00" (seqno 16).
Removed "/dev/sdb1" from volume group "VolGroup00"
練習という事で、いくつかやってみました。
まだ分かっていない事が多いから、実践を意識したケースを想定してまた色々やってみたいと思います。
今日はこんな所で。
