怎么创建一个伸缩磁盘呢?
本文标识 : L00024
本文编辑 : 灭霸 编程工具 : redhat7 阅读时长 : 10分钟
还是那个话要准备好磁盘
LVM的创建
[root@localhost /]# fdisk -l
磁盘 /dev/sda：21.5 GB, 21474836480 字节，41943040 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘标签类型：dos
磁盘标识符：0x00049a27
设备 Boot Start End Blocks Id System
/dev/sda1 * 2048 616447 307200 83 Linux
/dev/sda2 616448 17000447 8192000 82 Linux swap / Solaris
/dev/sda3 17000448 18638847 819200 83 Linux
/dev/sda4 18638848 41943039 11652096 5 Extended
/dev/sda5 18640896 41943039 11651072 83 Linux
磁盘 /dev/sdb：10.7 GB, 10737418240 字节，20971520 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘标签类型：dos
磁盘标识符：0x74ae20a2
设备 Boot Start End Blocks Id System
/dev/sdb1 2048 2099199 1048576 83 Linux
/dev/sdb2 2099200 6293503 2097152 83 Linux
/dev/sdb3 6293504 8390655 1048576 83 Linux
磁盘 /dev/sdc：10.7 GB, 10737418240 字节，20971520 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘 /dev/sdd：10.7 GB, 10737418240 字节，20971520 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节[root@localhost /]# pvcreate /dev/sdb[1-3]
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdb2" successfully created
Physical volume "/dev/sdb3" successfully created[root@localhost /]# pvscan
PV /dev/sdb1 lvm2 [1.00 GiB]
PV /dev/sdb2 lvm2 [2.00 GiB]
PV /dev/sdb3 lvm2 [1.00 GiB]
Total: 3 [4.00 GiB] / in use: 0 [0 ] / in no VG: 3 [4.00 GiB][root@localhost /]# pvdisplay
"/dev/sdb1" is a new physical volume of "1.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size 1.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID tHGdRY-B5MD-eZCu-2maQ-DXNl-YZFN-NQie3Y
"/dev/sdb2" is a new physical volume of "2.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb2
VG Name
PV Size 2.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 5dEYRc-dtgY-HEKu-ItY2-HEAU-lncy-Vjjyyp
"/dev/sdb3" is a new physical volume of "1.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb3
VG Name
PV Size 1.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID oTBpce-BBeX-jZHP-wGvx-Kpt5-eJIr-WSUcLB[root@localhost /]# vgcreate -s 4M snow /dev/sdb[1-3]
Volume group "snow" successfully created[root@localhost /]# vgscan
Reading all physical volumes. This may take a while...
Found volume group "snow" using metadata type lvm2[root@localhost /]# vgdisplay
--- Volume group ---
VG Name snow
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 3
Act PV 3
VG Size 3.99 GiB
PE Size 4.00 MiB
Total PE 1021
Alloc PE / Size 0 / 0
Free PE / Size 1021 / 3.99 GiB
VG UUID 65i9I5-nMjS-dGXJ-BXAZ-8vcn-ZP9v-XZomrM[root@localhost /]# lvcreate -L 3G -n lv snow
Logical volume "lv" created.[root@localhost /]# lvscan
ACTIVE '/dev/snow/lv' [3.00 GiB] inherit[root@localhost /]# lvdisplay
--- Logical volume ---
LV Path /dev/snow/lv
LV Name lv
VG Name snow
LV UUID dtQhW5-I8QK-tHal-lpnM-gCQM-4Ffd-eR4j3Y
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2019-11-10 20:05:02 +0800
LV Status available
# open 0
LV Size 3.00 GiB
Current LE 768
Segments 3
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0[root@localhost /]# mkfs.xfs /dev/snow/lv
meta-data=/dev/snow/lv isize=256 agcount=4, agsize=196608 blks
= sectsz=512 attr=2, projid32bit=1
= crc=0 finobt=0
data = bsize=4096 blocks=786432, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=0
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0[root@localhost /]# ls
admin boot etc lib media opt root sbin sys usr
bin dev home lib64 mnt proc run srv tmp var[root@localhost /]# cd /mnt/
[root@localhost mnt]# ls
[root@localhost mnt]# mkdir aa
[root@localhost mnt]# ls
aa[root@localhost mnt]# mount /dev/snow/lv aa/
[root@localhost aa]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda5 12G 2.9G 8.3G 27% /
devtmpfs 979M 0 979M 0% /dev
tmpfs 993M 144K 993M 1% /dev/shm
tmpfs 993M 9.0M 984M 1% /run
tmpfs 993M 0 993M 0% /sys/fs/cgroup
/dev/sda3 797M 36M 761M 5% /home
/dev/sda1 297M 130M 168M 44% /boot
tmpfs 199M 12K 199M 1% /run/user/0
/dev/sr0 3.8G 3.8G 0 100% /run/media/root/RHEL-7.2 Server.x86_64
/dev/mapper/snow-lv 3.0G 33M 3.0G 2% /mnt/aa看到这里就可以用了，挂载了lvm的aa以后目录写入的就是lvm里面的，当卸载下来挂到其他的目录下写到里面的内容就会跟随被带走。
扩展和减少也是类似，但是要注意扩展和减少的时候Resizefs /dev/snow/lv /扩展文件系统在扩展/缩减空间之后，空间表面上增加，但实际上仍然需要处理block总数，以达到块与空间容量是对应的。因此无论是扩展/缩减空间都需要对块重新resize。
期待一起成长
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原始发表：2019-11-25，如有侵权请联系 cloudcommunity@tencent.com 删除
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