在给RHEL进行扩容的时候提示有个lv找不到了。应该是分配给交换空间的lv找不到了，导致没法进行库容。下面是处理过程。
提示缺少一个pv导致无法继续
## 初始报错
[root@localhost ~]# pvdisplay
/dev/rhel/swap: read failed after 0 of 4096 at 4294901760: 输入/输出错误
/dev/rhel/swap: read failed after 0 of 4096 at 4294959104: 输入/输出错误
WARNING: Device for PV iUJdjw-C9S6-bRE7-jIdl-6kQ6-esLL-5vDGYE not found or rejected by a filter.
--- Physical volume ---
PV Name /dev/sda2
VG Name rhel
PV Size 19.51 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 4994
Free PE 0
Allocated PE 4994
PV UUID 81PW3j-W2eg-19qX-27NN-e1zr-750q-7u5ZIy
--- Physical volume ---
PV Name unknown device
VG Name rhel
PV Size 2.00 GiB / not usable 4.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 511
Free PE 9
Allocated PE 502
PV UUID iUJdjw-C9S6-bRE7-jIdl-6kQ6-esLL-5vDGYE
--- Physical volume ---
PV Name /dev/sda3
VG Name rhel
PV Size 10.00 GiB / not usable 4.00 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 2559
Free PE 2559
Allocated PE 0
PV UUID UVulsk-WJ3R-y7ga-EYT7-dfd8-26hY-sUucWK
# 扩容分区报错
[root@localhost ~]# lvextend -L +10236m /dev/mapper/rhel-root
WARNING: Device for PV iUJdjw-C9S6-bRE7-jIdl-6kQ6-esLL-5vDGYE not found or rejected by a filter.
Cannot change VG rhel while PVs are missing.
Consider vgreduce --removemissing.
# 提示某个pv丢失了
[root@localhost ~]# pvs
/dev/rhel/swap: read failed after 0 of 4096 at 4294901760: 输入/输出错误
/dev/rhel/swap: read failed after 0 of 4096 at 4294959104: 输入/输出错误
WARNING: Device for PV iUJdjw-C9S6-bRE7-jIdl-6kQ6-esLL-5vDGYE not found or rejected by a filter.
PV VG Fmt Attr PSize PFree
/dev/sda2 rhel lvm2 a-- 19.51g 0
/dev/sda3 rhel lvm2 a-- 10.00g 10.00g
unknown device rhel lvm2 a-m 2.00g 36.00m
添加一个磁盘
[root@localhost ~]# fdisk /dev/sdb
欢迎使用 fdisk (util-linux 2.23.2)。
更改将停留在内存中，直到您决定将更改写入磁盘。
使用写入命令前请三思。
Device does not contain a recognized partition table
使用磁盘标识符 0x14e3066c 创建新的 DOS 磁盘标签。
命令(输入 m 获取帮助)：m
命令操作
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
命令(输入 m 获取帮助)：n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
分区号 (1-4，默认 1)：
起始 扇区 (2048-8388607，默认为 2048)：
将使用默认值 2048
Last 扇区, +扇区 or +size{K,M,G} (2048-8388607，默认为 8388607)：
将使用默认值 8388607
分区 1 已设置为 Linux 类型，大小设为 4 GiB
命令(输入 m 获取帮助)：m
命令操作
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
命令(输入 m 获取帮助)：t
已选择分区 1
Hex 代码(输入 L 列出所有代码)：L
0 空 24 NEC DOS 81 Minix / 旧 Linu bf Solaris
1 FAT12 27 隐藏的 NTFS Win 82 Linux 交换 / So c1 DRDOS/sec (FAT-
2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 3c PartitionMagic 84 OS/2 隐藏的 C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 40 Venix 80286 85 Linux 扩展 c7 Syrinx
5 扩展 41 PPC PReP Boot 86 NTFS 卷集 da 非文件系统数据
6 FAT16 42 SFS 87 NTFS 卷集 db CP/M / CTOS / .
7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux 纯文本 de Dell 工具
8 AIX 4e QNX4.x 第2部分 8e Linux LVM df BootIt
9 AIX 可启动 4f QNX4.x 第3部分 93 Amoeba e1 DOS 访问
a OS/2 启动管理器 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad 休 eb BeOS fs
e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD ee GPT
f W95 扩展 (LBA) 54 OnTrackDM6 a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 55 EZ-Drive a7 NeXTSTEP f0 Linux/PA-RISC
11 隐藏的 FAT12 56 Golden Bow a8 Darwin UFS f1 SpeedStor
12 Compaq 诊断 5c Priam Edisk a9 NetBSD f4 SpeedStor
14 隐藏的 FAT16 <3 61 SpeedStor ab Darwin 启动 f2 DOS 次要
16 隐藏的 FAT16 63 GNU HURD or Sys af HFS / HFS+ fb VMware VMFS
17 隐藏的 HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST 智能睡眠 65 Novell Netware b8 BSDI swap fd Linux raid 自动
1b 隐藏的 W95 FAT3 70 DiskSecure 多启 bb Boot Wizard 隐 fe LANstep
1c 隐藏的 W95 FAT3 75 PC/IX be Solaris 启动 ff BBT
1e 隐藏的 W95 FAT1 80 旧 Minix
Hex 代码(输入 L 列出所有代码)：8e
已将分区“Linux”的类型更改为“Linux LVM”
命令(输入 m 获取帮助)：m
命令操作
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
命令(输入 m 获取帮助)：w
The partition table has been altered!
Calling ioctl() to re-read partition table.
正在同步磁盘。
[root@localhost ~]# fdisk -l
磁盘 /dev/sda：32.2 GB, 32212254720 字节，62914560 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：0x00049ebe
设备 Boot Start End Blocks Id System
/dev/sda1 * 2048 1026047 512000 83 Linux
/dev/sda2 1026048 41943039 20458496 8e Linux LVM
/dev/sda3 41943040 62914559 10485760 8e Linux LVM
磁盘 /dev/sdb：4294 MB, 4294967296 字节，8388608 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：0x14e3066c
设备 Boot Start End Blocks Id System
/dev/sdb1 2048 8388607 4193280 8e Linux LVM
磁盘 /dev/mapper/rhel-root：18.8 GB, 18756927488 字节，36634624 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
fdisk: 打不开 /dev/mapper/rhel-swap-missing_2_0: 输入/输出错误
[root@localhost ~]# mkfs.ext4 /dev/sdb1
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
262144 inodes, 1048320 blocks
52416 blocks (5.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=1073741824
32 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736
Allocating group tables: 完成
正在写入inode表: 完成
Creating journal (16384 blocks): 完成
Writing superblocks and filesystem accounting information: 完成
[root@localhost ~]# pvs
/dev/rhel/swap: read failed after 0 of 4096 at 4294901760: 输入/输出错误
/dev/rhel/swap: read failed after 0 of 4096 at 4294959104: 输入/输出错误
WARNING: Device for PV iUJdjw-C9S6-bRE7-jIdl-6kQ6-esLL-5vDGYE not found or rejected by a filter.
PV VG Fmt Attr PSize PFree
/dev/sda2 rhel lvm2 a-- 19.51g 0
/dev/sda3 rhel lvm2 a-- 10.00g 10.00g
unknown device rhel lvm2 a-m 2.00g 36.00m将新创建的pv管理到丢失的pv上
[root@localhost ~]# pvcreate --help
pvcreate: Initialize physical volume(s) for use by LVM
pvcreate
[--norestorefile]
[--restorefile file]
[--commandprofile ProfileName]
[-d|--debug]
[-f[f]|--force [--force]]
[-h|-?|--help]
[--labelsector sector]
[-M|--metadatatype 1|2]
[--pvmetadatacopies #copies]
[--bootloaderareasize BootLoaderAreaSize[bBsSkKmMgGtTpPeE]]
[--metadatasize MetadataSize[bBsSkKmMgGtTpPeE]]
[--dataalignment Alignment[bBsSkKmMgGtTpPeE]]
[--dataalignmentoffset AlignmentOffset[bBsSkKmMgGtTpPeE]]
[--setphysicalvolumesize PhysicalVolumeSize[bBsSkKmMgGtTpPeE]
[-t|--test]
[-u|--uuid uuid]
[-v|--verbose]
[-y|--yes]
[-Z|--zero {y|n}]
[--version]
PhysicalVolume [PhysicalVolume...]
[root@localhost ~]# pvcreate /dev/sdb1 --u iUJdjw-C9S6-bRE7-jIdl-6kQ6-esLL-5vDGYE --norestorefile
WARNING: Device for PV iUJdjw-C9S6-bRE7-jIdl-6kQ6-esLL-5vDGYE not found or rejected by a filter.
WARNING: ext4 signature detected on /dev/sdb1 at offset 1080. Wipe it? [y/n]: y
Wiping ext4 signature on /dev/sdb1.
Physical volume "/dev/sdb1" successfully created
[root@localhost ~]# pvs
/dev/rhel/swap: read failed after 0 of 4096 at 4294901760: 输入/输出错误
/dev/rhel/swap: read failed after 0 of 4096 at 4294959104: 输入/输出错误
PV VG Fmt Attr PSize PFree
/dev/sda2 rhel lvm2 a-- 19.51g 0
/dev/sda3 rhel lvm2 a-- 10.00g 10.00g
/dev/sdb1 rhel lvm2 a-m 2.00g 36.00m
依旧报错
[root@localhost ~]# lvextend -L +10236m /dev/rhel/root
Missing device /dev/sdb1 reappeared, updating metadata for VG rhel to version 7.
Device still marked missing because of allocated data on it, remove volumes and consider vgreduce --removemissing.
Cannot change VG rhel while PVs are missing.
Consider vgreduce --removemissing.
强制移除丢失的lv
[root@localhost ~]# vgreduce --removemissing rhel
WARNING: Partial LV swap needs to be repaired or removed.
There are still partial LVs in VG rhel.
To remove them unconditionally use: vgreduce --removemissing --force.
Proceeding to remove empty missing PVs.
[root@localhost ~]# vgreduce --removemissing rhel --force
Removing partial LV swap.
Logical volume rhel/swap in use.
[root@localhost ~]# vgscan
Reading all physical volumes. This may take a while...
Found volume group "rhel" using metadata type lvm2
[root@localhost ~]# vgchange -a y
Refusing activation of partial LV rhel/swap. Use '--activationmode partial' to override.
2 logical volume(s) in volume group "rhel" now active
关闭交换空间
[root@localhost ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root rhel -wi-ao---- 17.47g
swap rhel -wi-ao--p- 4.00g
[root@localhost ~]# swapoff -v /dev/rhel/swap
swapoff /dev/rhel/swap
[root@localhost ~]# vgreduce --removemissing rhel
WARNING: Partial LV swap needs to be repaired or removed.
There are still partial LVs in VG rhel.
To remove them unconditionally use: vgreduce --removemissing --force.
Proceeding to remove empty missing PVs.
[root@localhost ~]# vgreduce --removemissing rhel --force
Removing partial LV swap.
Logical volume "swap" successfully removed
Wrote out consistent volume group rhel
这次允许扩容了
[root@localhost ~]# lvextend -L +10236m /dev/rhel/root
Size of logical volume rhel/root changed from 17.47 GiB (4472 extents) to 27.46 GiB (7031 extents).
Logical volume root successfully resized.参考文章：
http://blog.itpub.net/17203031/viewspace-774174/