Ubuntu下如何创建XFS文件系统的LVM详解

前言

lvm(Logical Volume Manager) 逻辑卷管理， 可以满足linux系统动态调整各分区大小，满足服务器在不同的运行时期的需求。

以前在Linux下面玩LVM，一般都是选择ext3、ext4格式的文件系统，最近在Ubuntu 16.04.5下安装配置一个MySQL数据库服务器，遂测试了一下XFS文件系统的LVM，其实仔细对比下来，差别不大，只是文件格式化的区别以及件系统的调整命令的不同。下面很多地方不做过多解释，只是简单的记录测试过程。

在测试服务器新增一个磁盘，如下所示，新增的磁盘为/dec/sdc

root@mylnx12:~# fdisk -l
Disk /dev/sdb: 605 GiB, 649613803520 bytes, 1268776960 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x2c2c38b3
 
Device  Boot Start  End Sectors Size Id Type
/dev/sdb1  2048 1268774911 1268772864 605G 7 HPFS/NTFS/exFAT
 
 
Disk /dev/sda: 30 GiB, 32212254720 bytes, 62914560 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x6e2369f9
 
Device  Boot Start  End Sectors Size Id Type
/dev/sda1 *  2048 62914526 62912479 30G 83 Linux
 
 
Disk /dev/sdc: 1023 GiB, 1098437885952 bytes, 2145386496 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x030b81c8
 
Device  Boot Start  End Sectors Size Id Type
/dev/sdc1  2048 2145386495 2145384448 1023G 83 Linux
 
#创建PV
root@mylnx12:~# pvcreate /dev/sdc1
 Physical volume "/dev/sdc1" successfully created
root@mylnx12:~# pvscan
 PV /dev/sdc1      lvm2 [1023.00 GiB]
 Total: 1 [1023.00 GiB] / in use: 0 [0 ] / in no VG: 1 [1023.00 GiB]
 
#创建VG
root@mylnx12:~# vgcreate -s 32M VolGroup01 /dev/sdc1
 Volume group "VolGroup01" successfully created
 
#新增LV
root@mylnx12:~# lvcreate -L +400G -n LogVol00 VolGroup01
WARNING: xfs signature detected on /dev/VolGroup01/LogVol00 at offset 0. Wipe it? [y/n]: y
 Wiping xfs signature on /dev/VolGroup01/LogVol00.
 Logical volume "LogVol00" created.
root@mylnx12:~# lvscan
 ACTIVE   '/dev/VolGroup01/LogVol00' [400.00 GiB] inherit
 
#格式化
root@mylnx12:~# mkfs.xfs /dev/VolGroup01/LogVol00
meta-data=/dev/VolGroup01/LogVol00 isize=512 agcount=4, agsize=26214400 blks
   =      sectsz=512 attr=2, projid32bit=1
   =      crc=1  finobt=1, sparse=0
data  =      bsize=4096 blocks=104857600, imaxpct=25
   =      sunit=0  swidth=0 blks
naming =version 2    bsize=4096 ascii-ci=0 ftype=1
log  =internal log   bsize=4096 blocks=51200, version=2
   =      sectsz=512 sunit=0 blks, lazy-count=1
realtime =none     extsz=4096 blocks=0, rtextents=0
 
#挂载点设置
root@mylnx12:~# mkdir /mysql_data
root@mylnx12:~# mount -t xfs /dev/VolGroup01/LogVol00 /mysql_data
root@mylnx12:~# vgdisplay
 --- Volume group ---
 VG Name    VolGroup01
 System ID    
 Format    lvm2
 Metadata Areas  1
 Metadata Sequence No 2
 VG Access    read/write
 VG Status    resizable
 MAX LV    0
 Cur LV    1
 Open LV    0
 Max PV    0
 Cur PV    1
 Act PV    1
 VG Size    1022.97 GiB
 PE Size    32.00 MiB
 Total PE    32735
 Alloc PE / Size  12800 / 400.00 GiB
 Free PE / Size  19935 / 622.97 GiB
 VG UUID    8kutIc-bjId-rNWK-UCHo-TU2l-xkwa-idBXCj
 
#创建另外一个LV
root@mylnx12:~# lvcreate -l 19935 -n LogVol01 VolGroup01
 Logical volume "LogVol01" created.
root@mylnx12:~# mkfs.xfs /dev/VolGroup01/LogVol01
meta-data=/dev/VolGroup01/LogVol01 isize=512 agcount=4, agsize=40826880 blks
   =      sectsz=512 attr=2, projid32bit=1
   =      crc=1  finobt=1, sparse=0
data  =      bsize=4096 blocks=163307520, imaxpct=25
   =      sunit=0  swidth=0 blks
naming =version 2    bsize=4096 ascii-ci=0 ftype=1
log  =internal log   bsize=4096 blocks=79740, version=2
   =      sectsz=512 sunit=0 blks, lazy-count=1
realtime =none     extsz=4096 blocks=0, rtextents=0
root@mylnx12:~# mkdir /mysql_backup
root@mylnx12:~# mount -t xfs /dev/VolGroup01/LogVol01 /mysql_backup/
root@mylnx12:~# df -h
Filesystem      Size Used Avail Use% Mounted on
udev        6.9G  0 6.9G 0% /dev
tmpfs       1.4G 8.6M 1.4G 1% /run
/dev/sda1       30G 2.1G 27G 8% /
tmpfs       6.9G  0 6.9G 0% /dev/shm
tmpfs       5.0M  0 5.0M 0% /run/lock
tmpfs       6.9G  0 6.9G 0% /sys/fs/cgroup
/dev/sdb1      596G 70M 566G 1% /mnt
tmpfs       1.4G  0 1.4G 0% /run/user/1000
/dev/mapper/VolGroup01-LogVol00 400G 441M 400G 1% /mysql_data
/dev/mapper/VolGroup01-LogVol01 623G 668M 623G 1% /mysql_backup

修改配置文件/etc/fstab,在其增加下面配置信息，如下所示，以便永久保存，确保下次开机启动不丢失相关挂载点信息。

UUID="a72bd3f8-eb2d-40cb-92c3-d5e32c30d5ff" /mysql_data xfs defaults 0 2
UUID="33325d87-f3f4-4215-abf7-ee795724697e" /mysql_backup xfs defaults 0 2

另外，ext2/ext3/ext4文件系统的调整命令是resize2fs（增大和减小都支持），而XFS文件系统的调整命令是xfs_growfs（只支持增大），当然硬要减小的话，只能在减小后将逻辑分区重新通过mkfs.xfs命令重新格式化才能挂载上，这样的话这个逻辑分区上原来的数据就丢失了。其实没有什么意义。

参考资料：

https://www.jb51.net/article/148553.htm

总结