# 逻辑卷的基本概念
# 逻辑卷是从卷组中分配的虚拟分区
# 可以像普通分区一样使用
# 可以动态调整大小
# 无需重新分区

# lvcreate命令详解

# 1. 创建指定大小的逻辑卷
# lvcreate -L 50G -n datalv datavg
Logical volume “datalv” created.

# 2. 创建指定PE数量的逻辑卷
# lvcreate -l 12800 -n datalv datavg
Logical volume “datalv” created.

# 3. 创建使用卷组所有空闲空间的逻辑卷
# lvcreate -l 100%FREE -n datalv datavg
Logical volume “datalv” created.

# 4. 创建带有标签的逻辑卷
# lvcreate –addtag “data” -L 50G -n datalv datavg
Logical volume “datalv” created.

# 5. 创建带有特定类型的逻辑卷
# lvcreate -T datavg/thinpool -L 100G
Logical volume “thinpool” created.

# 6. 查看lvcreate命令的帮助
# lvcreate –help

# lvdisplay命令详解

# 1. 显示所有逻辑卷的详细信息
# lvdisplay
— Logical volume —
LV Path /dev/rhel/root
LV Name root
VG Name rhel
LV UUID 12345678-90ab-cdef-1234-567890abcdef
LV Write Access read/write
LV Creation host, time localhost, 2026-03-31 10:00:00 +0800
LV Status available
# open 1
LV Size 45.00 GiB
Current LE 11520
Segments 1
Allocation inherit
Read ahead sectors auto
– currently set to 256
Block device 253:0

— Logical volume —
LV Path /dev/rhel/swap
LV Name swap
VG Name rhel
LV UUID 87654321-0987-fedc-ba98-76543210fedc
LV Write Access read/write
LV Creation host, time localhost, 2026-03-31 10:00:00 +0800
LV Status available
# open 2
LV Size 4.00 GiB
Current LE 1023
Segments 1
Allocation inherit
Read ahead sectors auto
– currently set to 256
Block device 253:1

# 2. 显示特定逻辑卷的详细信息
# lvdisplay /dev/datavg/datalv
— Logical volume —
LV Path /dev/datavg/datalv
LV Name datalv
VG Name datavg
LV UUID 23456789-0abc-def1-2345-67890abcdef1
LV Write Access read/write
LV Creation host, time localhost, 2026-03-31 10:00:00 +0800
LV Status available
# open 0
LV Size 50.00 GiB
Current LE 12800
Segments 1
Allocation inherit
Read ahead sectors auto
– currently set to 256
Block device 252:18

# 3. 显示逻辑卷的摘要信息
# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
datalv datavg -wi-a—– 50.00g
root rhel -wi-ao—- 45.00g
swap rhel -wi-ao—- 4.00g

# 4. 显示逻辑卷的详细摘要信息
# lvs -v
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert LV UUID
datalv datavg -wi-a—– 50.00g 23456789-0abc-def1-2345-67890abcdef1
root rhel -wi-ao—- 45.00g 12345678-90ab-cdef-1234-567890abcdef
swap rhel -wi-ao—- 4.00g 87654321-0987-fedc-ba98-76543210fedc

# 5. 查看lvdisplay命令的帮助
# lvdisplay –help

# 场景：创建和查看逻辑卷

# 1. 查看卷组
# vgs
VG #PV #LV #SN Attr VSize VFree
datavg 1 0 0 wz–n- 50.00g 50.00g
rhel 1 2 0 wz–n- 49.00g 0

# 2. 创建逻辑卷
# lvcreate -L 50G -n datalv datavg
Logical volume “datalv” created.

# 3. 查看逻辑卷
# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
datalv datavg -wi-a—– 50.00g
root rhel -wi-ao—- 45.00g
swap rhel -wi-ao—- 4.00g

# 4. 查看逻辑卷详细信息
# lvdisplay /dev/datavg/datalv
— Logical volume —
LV Path /dev/datavg/datalv
LV Name datalv
VG Name datavg
LV UUID 23456789-0abc-def1-2345-67890abcdef1
LV Write Access read/write
LV Creation host, time localhost, 2026-03-31 10:00:00 +0800
LV Status available
# open 0
LV Size 50.00 GiB
Current LE 12800
Segments 1
Allocation inherit
Read ahead sectors auto
– currently set to 256
Block device 252:18

# 5. 查看卷组
# vgs
VG #PV #LV #SN Attr VSize VFree
datavg 1 1 0 wz–n- 50.00g 0
rhel 1 2 0 wz–n- 49.00g 0

# 6. 格式化逻辑卷
# mkfs.xfs /dev/datavg/datalv
meta-data=/dev/datavg/datalv isize=512 agcount=4, agsize=3276800 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1 bigtime=0 inobtcount=0
data = bsize=4096 blocks=13107200, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=6400, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0

# 7. 挂载逻辑卷
# mkdir -p /data
# mount /dev/datavg/datalv /data

# 8. 验证挂载
# df -h /data
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/datavg-datalv 50G 33M 50G 1% /data

# 9. 配置永久挂载
# echo ‘/dev/datavg/datalv /data xfs defaults 0 0’ >> /etc/fstab

# 10. 再次查看逻辑卷
# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
datalv datavg -wi-ao—- 50.00g
root rhel -wi-ao—- 45.00g
swap rhel -wi-ao—- 4.00g