调整磁盘大小及其上面的LVM
0. 前言
WTM知道LVM可以添加硬盘扩容！
WTM也知道分区大小可以扩大！
WTM知道在LVM上添加无数个虚拟硬盘不会影响性能！
但是哪个运维会这样子干啊！
最后几十个PV的LVM谁敢维护啊！
1. 操作
首先，/dev/mapper/iscsi-storage-srv 是已经被格式化为xfs系统的LV
- 挂载 /dev/mapper/iscsi-storage-srv 到 /srv 上
root@service:~# mount /dev/mapper/iscsi-storage-srv /srv
root@service:~# lsblk /dev/sdb
sdb 8:16 0 99G 0 disk
└─sdb1 8:17 0 99G 0 part
└─iscsi-storage-srv 254:3 0 99G 0 lvm /srv
- 确认挂载成功，输出xfs信息
root@service:~# xfs_info /dev/mapper/iscsi--storage-srv
meta-data=/dev/mapper/iscsi--storage-srv isize=512 agcount=4, agsize=6553344 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1 spinodes=0 rmapbt=0
= reflink=0
data = bsize=4096 blocks=26213376, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=12799, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
- 在虚拟机上拓展磁盘到100G，接着重新扫描磁盘
（我是通过SSH操作的，这里把dmesg的信息拷贝了过来）
root@service:~# echo 1 > /sys/block/sdb/device/rescan
[ 635.424954] sd 0:0:1:0: [sdb] 209715200 512-byte logical blocks: (107 GB/100 GiB)
[ 635.424959] sd 0:0:1:0: [sdb] 4096-byte physical blocks
[ 635.426115] sdb: detected capacity change from 106300440576 to 107374182400
- 通过
lsblk确认磁盘大小
root@service:~# lsblk /dev/sdb
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 100G 0 disk
└─sdb1 8:17 0 99G 0 part
└─iscsi-storage-srv 254:3 0 99G 0 lvm /srv
- 通过
parted调整分区大小
注意：通过parted的resizepart命令调整分区大小需要先通过print free来查看空闲区域的末尾位置。这里我没有调整单位大小，就在107GB后面随便加了个'.6'来确保分区末尾在磁盘的末尾。
可以使用unit B调整单位大小为B
另外，使用gpt分区表的话，会提示gpt分区表没有占满整个硬盘，询问是否修复？这里一定要修复，不然无法使用那部分空间。
root@service:~# parted /dev/sdb
GNU Parted 3.2
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print free
Warning: Not all of the space available to /dev/sdb appears to be used, you can fix the GPT to use all of the space (an extra 2097152 blocks) or continue with the current setting?
Fix/Ignore? Fix
Model: MSFT Virtual HD (scsi)
Disk /dev/sdb: 107GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
17.4kB 1049kB 1031kB Free Space
1 1049kB 106GB 106GB lvm
106GB 107GB 1074MB Free Space
(parted) resizepart 1 107.6GB
(parted) print free
Model: MSFT Virtual HD (scsi)
Disk /dev/sdb: 107GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
17.4kB 1049kB 1031kB Free Space
1 1049kB 107GB 107GB lvm
(parted) q
Information: You may need to update /etc/fstab.
- 通过
lsblk确认分区大小
root@service:~# lsblk /dev/sdb
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 100G 0 disk
└─sdb1 8:17 0 100G 0 part
└─iscsi-storage-srv 254:3 0 99G 0 lvm /srv
- 调整PV大小
root@service:~# pvdisplay /dev/sdb1
--- Physical volume ---
PV Name /dev/sdb1
VG Name iscsi-storage
PV Size 99.00 GiB / not usable 2.98 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 25343
Free PE 0
Allocated PE 25343
PV UUID bE4qfW-Wz4M-PSUf-PD3d-eHMK-pCtt-PCEWLe
root@service:~# pvresize /dev/sdb1
Physical volume "/dev/sdb1" changed
1 physical volume(s) resized / 0 physical volume(s) not resized
root@service:~# pvdisplay /dev/sdb1
--- Physical volume ---
PV Name /dev/sdb1
VG Name iscsi-storage
PV Size 100.00 GiB / not usable 1.98 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 25599
Free PE 256
Allocated PE 25343
PV UUID bE4qfW-Wz4M-PSUf-PD3d-eHMK-pCtt-PCEWLe
- 调整LV大小（使用 -r 同时调整 xfs 分区的大小）
root@service:~# lvresize -l +100%FREE /dev/iscsi-storage/srv -r
Size of logical volume iscsi-storage/srv changed from 99.00 GiB (25343 extents) to 100.00 GiB (25599 extents).
Logical volume iscsi-storage/srv successfully resized.
meta-data=/dev/mapper/iscsi-storage-srv isize=512 agcount=4, agsize=6487808 blks
= sectsz=4096 attr=2, projid32bit=1
= crc=1 finobt=1 spinodes=0 rmapbt=0
= reflink=0
data = bsize=4096 blocks=25951232, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=12671, version=2
= sectsz=4096 sunit=1 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 25951232 to 26213376
- 通过
lsblk确认分区大小
root@service:~# lsblk /dev/sdb
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 100G 0 disk
└─sdb1 8:17 0 100G 0 part
└─iscsi-storage-srv 254:3 0 100G 0 lvm /srv
- 通过
df -h确认文件系统大小
root@service:~# df -h /srv/
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/iscsi-storage-srv 100G 159M 100G 1% /srv
2. 总结(杂谈)
在写这篇记录的时候，一位运维的朋友跟我说现实中不会有这种情况的，有也是一下子加几十上百G的空间，VG再大的也不会塞几十个PV进去。但谁知道你老板会怎么叫你加空间啊？万一每次他觉得只加个10G就够了，或者只能给你10G，以后要再加，那怎么办？
我写这篇记录，只是为了记住这次实践而已。也只是好奇虚拟化技术出来这么久了，也没有前人弄个类似的方案写成文档。难道拓展容量真的是加虚拟硬盘吗？