|
Manage Logical Volumes
2015/07/18 |
|
This is the basic operation of managing Logical Volumes.
It needs to create Volume Group first. |
|
| [1] | Create Logical Volume. |
|
# create logical volume "lv_data" in volume group "vg_dlp" with 50G [root@dlp ~]# lvcreate -L 50G -n lv_data vg_dlp Logical volume "lv_data" created # specify like follows if you use all free area [root@dlp ~]# lvcreate -l 100%FREE -n lv_data vg_dlp Logical volume "lv_data" created |
| [2] | Display Logical Volumes. |
|
[root@dlp ~]# lvdisplay /dev/vg_dlp/lv_data --- Logical volume --- LV Path /dev/vg_dlp/lv_data LV Name lv_data VG Name vg_dlp LV UUID nlTuzs-T9nC-hRIC-4Vgh-Bm9G-t4EI-kTu2NU LV Write Access read/write LV Creation host, time dlp.srv.world, 2015-07-20 09:23:36 +0900 LV Status available # open 0 LV Size 80.00 GiB Current LE 20479 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:2 |
| [3] | Rename Logical Volume. |
|
# rename from lv_data to lv_storage [root@dlp ~]# lvrename vg_dlp lv_data lv_storage Renamed "lv_data" to "lv_storage" in volume group "vg_dlp" [root@dlp ~]# lvdisplay /dev/vg_dlp/lv_storage --- Logical volume --- LV Path /dev/vg_dlp/lv_storage LV Name lv_storage VG Name vg_dlp LV UUID nlTuzs-T9nC-hRIC-4Vgh-Bm9G-t4EI-kTu2NU LV Write Access read/write LV Creation host, time dlp.srv.world, 2015-07-20 09:23:36 +0900 LV Status available # open 0 LV Size 80.00 GiB Current LE 20479 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:2 |
| [4] | Display reports of Logical Volumes. |
|
[root@dlp ~]# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert root centos -wi-ao---- 45.62g swap centos -wi-ao---- 3.89g lv_storage vg_dlp -wi-a----- 80.00g |
| [5] | Scan Logical Volumes. |
|
[root@dlp ~]# lvscan ACTIVE '/dev/centos/swap' [3.89 GiB] inherit ACTIVE '/dev/centos/root' [45.62 GiB] inherit ACTIVE '/dev/vg_dlp/lv_storage' [80.00 GiB] inherit |
| [6] | Take snapshot of Logical Volume. |
|
# create snapshot "snap-lv_storage" from "lv_storage" [root@dlp ~]# lvcreate -s -L 50G -n snap-lv_storage /dev/vg_dlp/lv_storage Logical volume "snap-lv_storage" created. [root@dlp ~]# lvdisplay /dev/vg_dlp/lv_storage /dev/vg_dlp/snap-lv_storage
--- Logical volume ---
LV Path /dev/vg_dlp/lv_storage
LV Name lv_storage
VG Name vg_dlp
LV UUID M7mPAd-e2BU-XIVY-z7tN-5SBS-eEiX-biB90f
LV Write Access read/write
LV Creation host, time dlp.srv.world, 2015-07-20 09:33:33 +0900
LV snapshot status source of
snap-lv_storage [active]
LV Status available
# open 0
LV Size 30.00 GiB
Current LE 7680
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:2
--- Logical volume ---
LV Path /dev/vg_dlp/snap-lv_storage
LV Name snap-lv_storage
VG Name vg_dlp
LV UUID YjbZR4-Snih-3KEE-O26y-vbQb-sLBq-Uv1CIJ
LV Write Access read/write
LV Creation host, time dlp.srv.world, 2015-07-20 09:34:21 +0900
LV snapshot status active destination for lv_storage
LV Status available
# open 0
LV Size 30.00 GiB
Current LE 7680
COW-table size 30.00 GiB
COW-table LE 7680
Allocated to snapshot 0.00%
Snapshot chunk size 4.00 KiB
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:5
|
| [7] | Extend Logical Volume. It's possible to do with mounted. |
|
[root@dlp ~]# lvextend -L 70G /dev/vg_dlp/lv_storage Size of logical volume vg_dlp/lv_storage changed from 30.00 GiB (7680 extents) to 50.00 GiB (12800 extents). Logical volume lv_storage successfully resized [root@dlp ~]# lvdisplay /dev/vg_dlp/lv_storage --- Logical volume --- LV Path /dev/vg_dlp/lv_storage LV Name lv_storage VG Name vg_dlp LV UUID M7mPAd-e2BU-XIVY-z7tN-5SBS-eEiX-biB90f LV Write Access read/write LV Creation host, time dlp.srv.world, 2015-07-20 09:33:33 +0900 LV Status available # open 1 LV Size 70.00 GiB Current LE 17920 Segments 1 Allocation inherit Read ahead sectors auto - currently set to 8192 Block device 253:2 # for the case of extending xfs filesystem (specify mount point) [root@dlp ~]# xfs_growfs /mnt
meta-data=/dev/mapper/vg_dlp-lv_storage isize=256 agcount=4, agsize=3276800 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0 finobt=0
data = bsize=4096 blocks=13107200, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal bsize=4096 blocks=6400, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 13107200 to 18350080
# for the case of extending ext4 filesystem [root@dlp ~]# resize2fs /dev/vg_dlp/lv_storage resize2fs 1.42.9 (28-Dec-2013) Filesystem at /dev/vg_dlp/lv_storage is mounted on /mnt; on-line resizing required old_desc_blocks = 7, new_desc_blocks = 9 [ 2296.232115] EXT4-fs (dm-2): resizing filesystem from 13107200 to 18350080 blocks [ 2296.258785] EXT4-fs (dm-2): resized filesystem to 18350080 The filesystem on /dev/vg_dlp/lv_storage is now 18350080 blocks long. |
| [8] | Reduce Logical Volume. Unmount target device first. It's impossible to reduce xfs filesystem. |
|
# for ext4, check it first [root@dlp ~]# e2fsck -f /dev/vg_dlp/lv_storage 50G e2fsck 1.42.9 (28-Dec-2013) Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information /dev/vg_dlp/lv_storage: 11/4587520 files (0.0% non-contiguous), 334056/18350080 blocks # for ext4, reduce filesystem [root@dlp ~]# resize2fs /dev/vg_dlp/lv_storage 50G resize2fs 1.42.9 (28-Dec-2013) Resizing the filesystem on /dev/vg_dlp/lv_storage to 13107200 (4k) blocks. The filesystem on /dev/vg_dlp/lv_storage is now 13107200 blocks long. # reduce logical volmue at last [root@dlp ~]# lvreduce -L 50G /dev/vg_dlp/lv_storage WARNING: Reducing active logical volume to 50.00 GiB THIS MAY DESTROY YOUR DATA (filesystem etc.) Do you really want to reduce lv_storage? [y/n]: y Size of logical volume vg_dlp/lv_storage changed from 70.00 GiB (17920 extents) to 50.00 GiB (12800 extents). Logical volume lv_storage successfully resized |
| [9] | Delete Logical Volume. unmount ⇒ stop logical volume ⇒ delete logical volume |
|
[root@dlp ~]# lvchange -an /dev/vg_dlp/lv_storage [root@dlp ~]# lvremove /dev/vg_dlp/lv_storage Logical volume "lv_storage" successfully removed |