使用DD手工恢复PVID信息

测试环境：aix 7100-03-03-1415

1.测试-使用testvg，testvg已经创建文件系统并存放数据

# lspv
hdisk0          00c68ebbc8661d02                    rootvg          active
hdisk1          00c68ebb6f10eb15                    testvg          active
hdisk2          00c68ebb8de4c792                    testvg          active
hdisk3          none                                None

# lsvg -l testvg
testvg:
LV NAME             TYPE       LPs     PPs     PVs  LV STATE      MOUNT POINT
loglv00             jfs2log    1       1       1    open/syncd    N/A
fslv00              jfs2       4       4       1    open/syncd    /test
# cd /test
# ls -l
total 0
drwxr-xr-x    2 root     system          256 Jun 26 13:11 abc
drwxr-xr-x    2 root     system          256 Jun 26 13:10 lost+found
# cd abc
# ls -l
total 8
-rw-r--r--    1 root     system           23 Jun 26 13:11 test.txt
# cat test.txt
This is a test file!!!

2.以hdisk2为例，先列出hdisk2的pvid信息

hdisk2在ODM中的信息

# lspv
hdisk0          00c68ebbc8661d02                    rootvg          active
hdisk1          00c68ebb6f10eb15                    testvg          active
hdisk2          00c68ebb8de4c792                    testvg          active
hdisk3          none                                None

hdisk2在VGDA中的信息

# lqueryvg -Atp hdisk2
Max LVs:        256
PP Size:        27
Free PPs:       1634
LV count:       2
PV count:       2
Total VGDAs:    3
Conc Allowed:   0
MAX PPs per PV: 32768
MAX PVs:        1024
Quorum (disk):  1
Quorum (dd):    1
Auto Varyon ?:  2
Conc Autovaryon 0
Varied on Conc: 0
Logical:        00c68ebb00004c00000001558de6cbe4.1   loglv00 1 
                00c68ebb00004c00000001558de6cbe4.2   fslv00 1 
Physical:       00c68ebb6f10eb15                2   0 
                00c68ebb8de4c792                1   0 
Total PPs:      1639
LTG size:       128
HOT SPARE:      0
AUTO SYNC:      0
VG PERMISSION:  0
SNAPSHOT VG:    0
IS_PRIMARY VG:  0
PSNFSTPP:       139520
VARYON MODE:    0
VG Type:        2
Max PPs:        32768
Mirror Pool Str n
Sys Mgt Mode:   0
VG Reserved:    1
PV RESTRICTION: 0
Infinite Retry: 2
Varyon State:   0
Disk Block Size 512

hdisk在盘头的信息显示

# lquerypv -H /dev/hdisk2
00c68ebb8de4c7920000000000000000

3.执行破坏测试

执行后，ODM库中的pvid发生了变化（蓝色部分）

# umount /test
# varyoffvg testvg
# chdev -l hdisk2 -a pv=clear
hdisk2 changed
# chdev -l hdisk2 -a pv=yes 
hdisk2 changed
# lspv
hdisk0          00c68ebbc8661d02                    rootvg          active     
hdisk1          00c68ebb6f10eb15                    testvg                     
hdisk2          00c68ebb8df07242                    None                       
hdisk3          none                                None        

VGDA中的PVID信息并没有发生变化

# lqueryvg -Atp hdisk2
0516-320 lqueryvg: Physical volume hdisk2 is not assigned to
        a volume group.
Max LVs:        256
PP Size:        27
Free PPs:       1634
LV count:       2
PV count:       2
Total VGDAs:    3
Conc Allowed:   0
MAX PPs per PV: 32768
MAX PVs:        1024
Quorum (disk):  1
Quorum (dd):    ???????
Auto Varyon ?:  2
Conc Autovaryon 0
Varied on Conc: 0
Logical:        00c68ebb00004c00000001558de6cbe4.1   loglv00 1 
                00c68ebb00004c00000001558de6cbe4.2   fslv00 1 
Physical:       00c68ebb6f10eb15                2   0 
                00c68ebb8de4c792                1   0 
Total PPs:      1639
LTG size:       128
HOT SPARE:      0
AUTO SYNC:      0
VG PERMISSION:  0
SNAPSHOT VG:    0
IS_PRIMARY VG:  0
PSNFSTPP:       139520
VARYON MODE:    ???????
VG Type:        2
Max PPs:        32768
Mirror Pool Str n
Sys Mgt Mode:   ???????
VG Reserved:    ???????
PV RESTRICTION: ???????
Infinite Retry: 2
Varyon State:   0
Disk Block Size 512

盘头的信息也发生了变化。

# lquerypv -H /dev/hdisk2
00c68ebb8df072420000000000000000

此时，激活卷组会报错

# varyonvg testvg
0516-510 varyonvg: Physical volume not found for physical volume
        identifier 00c68ebb8de4c792.

4.重新将原有的PVID写入盘头

先把PVID：00c68ebb6f0db4c0转换成8进制数值，可以使用bc命令：

# bc
ibase=16
obase=8
00
0
C6
306
8E
216
BB
273
8D
215
E4
344
C7
307
92
222

转换完成后为：0000 0306 0216 0273 0215 0344 0307 0222

将数值写入盘头，命令如下：

#  echo "\\0000\\0306\\0216\\0273\\0215\\0344\\0307\\0222\\c" | dd of=/dev/hdisk2 bs=1 seek=128
8+0 records in.
8+0 records out.

转换成功后，查询盘头，正常。 odm还是00c68ebb8df07242

# lquerypv -H /dev/hdisk2
00c68ebb8de4c7920000000000000000
# lspv
hdisk0          00c68ebbc8661d02                    rootvg          active     
hdisk1          00c68ebb6f10eb15                    None                       
hdisk2          00c68ebb8df07242                    None                       
hdisk3          none                                None       

此时，盘头和vgda的信息一致了（00c68ebb8de4c792 ），ODM还不一致
5.这时，激活卷组，还是会报错，删除磁盘重新识别

# rmdev -dl hdisk2
hdisk2 deleted
# cfgmgr
# lspv
hdisk0          00c68ebbc8661d02                    rootvg          active     
hdisk1          00c68ebb6f10eb15                    testvg                         
hdisk2          00c68ebb8de4c792                    None                       
hdisk3          none                                None       

6.重新导入vg，后成功。 检查数据

# exportvg testvg
# importvg -y testvg hdisk2
testvg

# lsvg -l testvg
testvg:
LV NAME             TYPE       LPs     PPs     PVs  LV STATE      MOUNT POINT
loglv00             jfs2log    1       1       1    closed/syncd  N/A
fslv00              jfs2       4       4       1    closed/syncd  /test
# mount /test
# cd /test
# ls -l
total 0
drwxr-xr-x    2 root     system          256 Jun 26 13:11 abc
drwxr-xr-x    2 root     system          256 Jun 26 13:10 lost+found
# cd abc
# ls -l
total 8
-rw-r--r--    1 root     system           23 Jun 26 13:11 test.txt
# cat test.txt
This is a test file!!!