故障原因：服务器异常重启之后，识别不到PV，故障现象如下
[root@app-03 ~]# pvs
WARNING: Device for PV 13uLNW-NTlU-vut8-rbjU-u3FX-CGR0-GghK6n not found or rejected by a filter.
Couldn't find device with uuid 13uLNW-NTlU-vut8-rbjU-u3FX-CGR0-GghK6n.
PV VG Fmt Attr PSize PFree
/dev/sda backupvg lvm2 a-- 2.18t 187.61g
/dev/sdf oradatavg lvm2 a-- 894.25g 252.50g
/dev/sdn3 rootvg lvm2 a-- 64.00g 0
/dev/sdn4 oraclevg lvm2 a-- <300.00g <100.00g
/dev/sdn5 rootvg lvm2 a-- <54.00g 0
/dev/sdn6 rootvg lvm2 a-- <98.00g 0
[unknown] oradatavg lvm2 a-m 894.25g 0
[root@app-03 ~]# vgs
WARNING: Device for PV 13uLNW-NTlU-vut8-rbjU-u3FX-CGR0-GghK6n not found or rejected by a filter.
Couldn't find device with uuid 13uLNW-NTlU-vut8-rbjU-u3FX-CGR0-GghK6n.
VG #PV #LV #SN Attr VSize VFree
backupvg 1 1 0 wz--n- 2.18t 187.61g
oraclevg 1 1 0 wz--n- <300.00g <100.00g
oradatavg 2 1 0 wz-pn- <1.75t 252.50g
rootvg 3 5 0 wz--n- 215.99g 0
Linux的LVM会默认存储用户对PV/VG/LV的每一步操作，并自动把当前的VG的信息备份到一个文件里面，位置是/etc/lvm/backup/VG名。
这个文件里面记录的东西大概跟vgdisplay/pvdisplay/lvdisplay输出的信息一致，里面也包括了对于恢复VG信息至关重要的PVUUID。
这个文件记录的信息大概就相当于整个VG的元数据，这个文件非常重要，通过这个文件来恢复整个VG的信息
可以看到 PV0 Sde就是丢失盘的UUID
[root@app-03 ~]# cat /etc/lvm/backup/oradatavg
# Generated by LVM2 version 2.02.180(2)-RHEL7 (2018-07-20): Wed Aug 28 14:42:20 2019
contents = "Text Format Volume Group"
version = 1
description = "Created *after* executing 'lvcreate -L 1572864M -n lv_oracle_data oradatavg'"
creation_host = "app-03" # Linux app-03 3.10.0-957.el7.x86_64 #1 SMP Thu Nov 8 23:39:32 UTC 2018 x86_64
creation_time = 1566974540 # Wed Aug 28 14:42:20 2019
oradatavg {
id = "efT5Up-yfH0-qVus-MV1G-csWl-fhMW-B3jvba"
seqno = 2
format = "lvm2" # informational
status = ["RESIZEABLE", "READ", "WRITE"]
flags = []
extent_size = 8192 # 4 Megabytes
max_lv = 0
max_pv = 0
metadata_copies = 0
physical_volumes {
pv0 {
id = "13uLNW-NTlU-vut8-rbjU-u3FX-CGR0-GghK6n"
device = "/dev/sde" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 1875385008 # 894.253 Gigabytes
pe_start = 2048
pe_count = 228928 # 894.25 Gigabytes
}
pv1 {
id = "REBnPF-3f0t-a3w5-XHZ2-H0ML-T5og-edthrO"
device = "/dev/sdf" # Hint only
status = ["ALLOCATABLE"]
flags = []
dev_size = 1875385008 # 894.253 Gigabytes
pe_start = 2048
pe_count = 228928 # 894.25 Gigabytes
}
}
logical_volumes {
lv_oracle_data {
id = "tzR0gr-BKGI-yBts-48xW-B9ya-Flrv-gco616"
status = ["READ", "WRITE", "VISIBLE"]
flags = []
creation_time = 1566974540 # 2019-08-28 14:42:20 +0800
creation_host = "app-03"
segment_count = 2
segment1 {
start_extent = 0
extent_count = 228928 # 894.25 Gigabytes
type = "striped"
stripe_count = 1 # linear
stripes = [
"pv0", 0
]
}
segment2 {
start_extent = 228928
extent_count = 164288 # 641.75 Gigabytes
type = "striped"
stripe_count = 1 # linear
stripes = [
"pv1", 0
]
}
}
}
}
恢复步骤：
[root@app-03 ~]# pvcreate /dev/sde -u 13uLNW-NTlU-vut8-rbjU-u3FX-CGR0-GghK6n --restorefile /etc/lvm/backup/oradatavg // 使用原来的PV UUID来创建PV，并使用自动备份的文件来恢复信息
Couldn't find device with uuid 13uLNW-NTlU-vut8-rbjU-u3FX-CGR0-GghK6n.
WARNING: Device for PV 13uLNW-NTlU-vut8-rbjU-u3FX-CGR0-GghK6n not found or rejected by a filter.
Physical volume "/dev/sde" successfully created.
[root@app-03 ~]# vgcfgrestore oradatavg // 恢复datavg的vg信息
Restored volume group oradatavg
Scan of VG oradatavg from /dev/sde found metadata seqno 3 vs previous 2.
Scan of VG oradatavg from /dev/sdf found metadata seqno 3 vs previous 2.
恢复完成后，挂载目录显示lv不存在
[root@app-03 ~]# mount /dev/oradatavg/lv_oracle_data /oradata
mount: special device /dev/oradatavg/lv_oracle_data does not exist
查看lv时，lv还是存在的
[root@app-03 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv_ora_backup backupvg -wi-ao---- 2.00t
lv_oracle_home oraclevg -wi-ao---- 200.00g
lv_oracle_data oradatavg -wi------- 1.50t
lvhome rootvg -wi-ao---- 1.00g
lvopt rootvg -wi-ao---- 10.00g
lvroot rootvg -wi-ao---- <73.00g
lvswap rootvg -wi-ao---- 32.00g
lvvar rootvg -wi-ao---- <100.00g
lvmdisplay查看到lv状态是未激活
lvdisplay
--- Logical volume ---
LV Path /dev/oradatavg/lv_oracle_data
LV Name lv_oracle_data
VG Name oradatavg
LV UUID tzR0gr-BKGI-yBts-48xW-B9ya-Flrv-gco616
LV Write Access read/write
LV Creation host, time app-03, 2019-08-28 14:42:20 +0800
LV Status NOT available
LV Size 1.50 TiB
Current LE 393216
Segments 2
Allocation inherit
Read ahead sectors auto
激活lv
[root@app-03 ~]# vgchange -ay oradatavg
1 logical volume(s) in volume group "oradatavg" now active
--- Logical volume ---
LV Path /dev/oradatavg/lv_oracle_data
LV Name lv_oracle_data
VG Name oradatavg
LV UUID tzR0gr-BKGI-yBts-48xW-B9ya-Flrv-gco616
LV Write Access read/write
LV Creation host, time app-03, 2019-08-28 14:42:20 +0800
LV Status available
# open 0
LV Size 1.50 TiB
Current LE 393216
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:
激活后再挂载，挂载正常
注：如果换了一个新的没有数据盘的，此vg下的lv还需要从新格式化