有关LVCB的背景知识，请参考AIX的相关资料。我在这里就不啰嗦了。首先建立一个LV并在上面建立FS，建好后的情况如下：
/dev/sjhlv 0.08 0.08 1% 6 1% /lvcbtest
#lsvg -l sjhvg
sjhvg:
LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT
sjhlv jfs2 10 10 1 open/syncd /lvcbtest
loglv02 jfs2log 1 1 1 open/syncd N/A
#cd /lvcbtest
#ls
config.xml lost+found webAppConfig.xml
man getlvcb
Manual entry for getlvcb not found or not installed.
#getlvcb -TA sjhlv
AIX LVCB
intrapolicy = m
copies = 1
interpolicy = m
lvid = 00c2c87200004c00000001203c5bee8a.1
lvname = sjhlv
label = /lvcbtest
machine id = 2C8724C00
number lps = 10
relocatable = y
strict = y
stripe width = 0
stripe size in exponent = 0
type = jfs2
upperbound = 32
fs = vfs=jfs2:log=/dev/loglv02:options=rw:account=false
time created = Wed Mar 25 14:03:55 2009
time modified = Sat Apr 11 09:46:45 2009
--以上简单的列了一下FS中的文件，同时给出了lvcb的内容作为以下实验的参考。
dd if=/dev/zero of=/dev/sjhlv bs=512 count=1 --破坏lvcb的内容。
1+0 records in
1+0 records out
#getlvcb -TA sjhlv
intrapolicy =
copies = 0
interpolicy =
lvid =
lvname =
label =
machine id =
number lps = 0
relocatable =
strict =
stripe width = 0
stripe size in exponent = 0
type =
upperbound = 0
fs =
time created = time modified =
--此时lvcb的内容被清空了。
#cd /lvcbtest
#ls
config.xml lost+found webAppConfig.xml
#more config.xml
Provides the following main targets:
#umount /lvcbtest
#mount /lvcbtest
#cd /lvcbtest
#ls
config.xml lost+found webAppConfig.xml
--从上面的输出我们可以看到虽然lvcb被清空，但LV及其上的FS都没有问题，依然可以正常使用。
下面我们开始对LVCB的内容进行恢复：
#echo "AIX LVCB\0" | dd of=/dev/sjhlv bs=1 count=9
9+0 records in
9+0 records out
--这一步是必须的，否则会报这样的错：
#synclvodm -vP sjhvg sjhlv
synclvodm: Physical volume data updated.
0516-622 synclvodm: Warning, cannot write lv control block data.
synclvodm: Logical volume sjhlv updated.
#getlvcb -TA sjhlv
AIX LVCB
intrapolicy =
copies = 0
interpolicy =
lvid =
lvname =
label =
machine id =
number lps = 0
relocatable =
strict =
stripe width = 0
stripe size in exponent = 0
type =
upperbound = 0
fs =
time created = time modified =
--把逻辑卷标志写到从逻辑卷开始的9个字节中。
#synclvodm -vP sjhvg sjhlv
synclvodm: Physical volume data updated.
synclvodm: Logical volume sjhlv updated.
#getlvcb -TA sjhlv
AIX LVCB
intrapolicy = m
copies = 1
interpolicy = m
lvid = 00c2c87200004c00000001203c5bee8a.1
lvname = sjhlv
label =
machine id =
number lps = 10
relocatable = y
strict = y
stripe width = 0
stripe size in exponent = 0
type = jfs2
upperbound = 32
fs =
time created = time modified = Sat Apr 11 10:34:11 2009
--用VGDA的数据同步ODM，ODM多的VGDA不管，不更新。然后会把ODM库中关于这个LV的参数写入LV卷头4KB中。最后我们看到一些信息还是没有恢复，比如：label = ，machine id = ，fs =等。LVCB的信息存在三份，分别在lv的头部，VGDA，ODM。我猜测VGDA，ODM只含有LVCB的部分信息。通过这个命令可以看到vgda的内容：#readvgda -v /dev/hdisk5 我们只看sjhlv的信息：
********** Logical Volume: sjhlv ***********
lve.lvname: 0
lve.maxsize: 512
lve.lv_state: 1
lve.mirror: 1
lve.mirror_policy: 2
lve.num_lps: 10
lve.permissions: 1
lve.bb_relocation: 1
lve.write_verify: 2
lve.mirwrt_consist: 1
lve.stripe_exp: 0
lve.striping_width: 0
lve.lv_avoid: 0
lve.child_minor_num: 0
#chfs -a log=/dev/loglv02 /lvcbtest
#getlvcb -TA sjhlv
AIX LVCB
intrapolicy = m
copies = 1
interpolicy = m
lvid = 00c2c87200004c00000001203c5bee8a.1
lvname = sjhlv
label =
machine id = 2C8724C00
number lps = 10
relocatable = y
strict = y
stripe width = 0
stripe size in exponent = 0
type = jfs2
upperbound = 32
fs = vfs=jfs2:log=/dev/loglv02:options=rw:account=false
time created = time modified = Sat Apr 11 10:40:50 2009
--用chfs命令按照ODM数据库中的其它内容，进行恢复。到现在位置还有label，time created条目没有恢复。
#putlvcb -L /lvcbtest sjhlv
[test1:/]#getlvcb -TA sjhlv
AIX LVCB
intrapolicy = m
copies = 1
interpolicy = m
lvid = 00c2c87200004c00000001203c5bee8a.1
lvname = sjhlv
label = /lvcbtest
machine id = 2C8724C00
number lps = 10
relocatable = y
strict = y
stripe width = 0
stripe size in exponent = 0
type = jfs2
upperbound = 32
fs = vfs=jfs2:log=/dev/loglv02:options=rw:account=false
time created = time modified = Sat Apr 11 10:58:16 2009
--The putlvcb command writes the control block information into block 0 of the
logical volume lvname. Only the fields specified are written. putlvcb can be
used to write a new control block or update an existing one.直接修改LVCB的条目。time created条目依然没有恢复，暂时不管它。
#varyoffvg sjhvg
#exportvg sjhvg
--OK,我们现在在其他机器上importvg试试看，这个LV有没有问题。
#importvg -y sjhvg hdisk7
sjhvg
#mount /lvcbtest
#cd /lvcbtest
#ls
config.xml lost+found webAppConfig.xml
#more config.xml
Provides the following main targets:
* installService: Installs Apache as service (on Windows only). Input
properties are:
#getlvcb -AT sjhlv
AIX LVCB
intrapolicy = m
copies = 1
interpolicy = m
lvid = 00c2c87200004c00000001203c5bee8a.1
lvname = sjhlv
label = /lvcbtest
machine id = 2C8724C00
number lps = 10
relocatable = y
strict = y
stripe width = 0
stripe size in exponent = 0
type = jfs2
upperbound = 32
fs = vfs=jfs2:log=/dev/loglv02:options=rw:account=false
time created = time modified = Sat Apr 11 10:58:16 2009
#lslv sjhlv
LOGICAL VOLUME: sjhlv VOLUME GROUP: sjhvg
LV IDENTIFIER: 00c2c87200004c00000001203c5bee8a.1 PERMISSION: read/write
VG STATE: active/complete LV STATE: opened/syncd
TYPE: jfs2 WRITE VERIFY: off
MAX LPs: 512 PP SIZE: 8 megabyte(s)
COPIES: 1 SCHED POLICY: parallel
LPs: 10 PPs: 10
STALE PPs: 0 BB POLICY: relocatable
INTER-POLICY: minimum RELOCATABLE: yes
INTRA-POLICY: middle UPPER BOUND: 32
MOUNT POINT: /lvcbtest LABEL: /lvcbtest
MIRROR WRITE CONSISTENCY: on/ACTIVE
EACH LP COPY ON A SEPARATE PV ?: yes
Serialize IO ?: NO
--经测试一切OK。
我们继续搞破坏。
#dd if=/dev/zero of=/dev/sjhlv bs=512 count=1
1+0 records in
1+0 records out
#getlvcb -AT sjhlv
intrapolicy =
copies = 0
interpolicy =
lvid =
lvname =
label =
machine id =
number lps = 0
relocatable =
strict =
stripe width = 0
stripe size in exponent = 0
type =
upperbound = 0
fs =
time created = time modified =
--上面这个过程是在本机上继续上次破坏的操作。
下面的操作是在异机恢复lvcb。注意异机的ODM库已经没有sjhvg的任何信息。
#importvg -y sjhvg hdisk7
0516-622 synclvodm: Warning, cannot write lv control block data.
sjhvg
--无法得到此LV的信息，因为信息在LVCB上。
#lsvg -l sjhvg
sjhvg:
LV NAME TYPE LPs PPs PVs LV STATE MOUNT POINT
sjhlv 10 10 1 closed/syncd N/A
loglv02 jfs2log 1 1 1 closed/syncd N/A
--LV能看到。
#mount /lvcbtest
mount: /lvcbtest is not a known file system
--但无法mount FS
#getlvcb -AT sjhlv
intrapolicy =
copies = 0
interpolicy =
lvid =
lvname =
label =
machine id =
number lps = 0
relocatable =
strict =
stripe width = 0
stripe size in exponent = 0
type =
upperbound = 0
fs =
time created = time modified =
--什么信息都没有。
开始按照本机的恢复方法在异机恢复lvcb的内容
#echo "AIX LVCB\0" | dd of=/dev/sjhlv bs=1 count=9
9+0 records in
9+0 records out
#getlvcb -AT sjhlv
AIX LVCB
intrapolicy =
copies = 0
interpolicy =
lvid =
lvname =
label =
machine id =
number lps = 0
relocatable =
strict =
stripe width = 0
stripe size in exponent = 0
type =
upperbound = 0
fs =
time created = time modified =
#synclvodm -vP sjhvg sjhlv
synclvodm: Physical volume data updated.
synclvodm: Logical volume sjhlv updated.
#getlvcb -AT sjhlv
AIX LVCB
intrapolicy = m
copies = 1
interpolicy = m
lvid = 00c2c87200004c00000001203c5bee8a.1
lvname = sjhlv
label =
machine id =
number lps = 10
relocatable = n
strict = y
stripe width = 0
stripe size in exponent = 0
type =
upperbound = 32
fs =
time created = time modified = Sat Apr 11 11:53:09 2009
#chfs -a log=/dev/loglv02 /lvcbtest
chfs: No record matching '/lvcbtest' was found in /etc/filesystems.
--我把本机/etc/filesystems中关于lvcbtest的信息copy到异机。内容如下：
/lvcbtest:
dev = /dev/sjhlv
vfs = jfs2
log = /dev/loglv02
mount = false
check = false
options = rw
account = false
#chfs -a log=/dev/loglv02 /lvcbtest --需要注意lv不要与异机的lv同名。
#getlvcb -AT sjhlv
AIX LVCB
intrapolicy = m
copies = 1
interpolicy = m
lvid = 00c2c87200004c00000001203c5bee8a.1
lvname = sjhlv
label =
machine id = 2C8724C00
number lps = 10
relocatable = n
strict = y
stripe width = 0
stripe size in exponent = 0
type =
upperbound = 32
fs = vfs=jfs2:log=/dev/loglv02:options=rw:account=false
time created = time modified = Sat Apr 11 13:26:28 2009
#putlvcb -L /lvcbtest sjhlv
#getlvcb -AT sjhlv
AIX LVCB
intrapolicy = m
copies = 1
interpolicy = m
lvid = 00c2c87200004c00000001203c5bee8a.1
lvname = sjhlv
label = /lvcbtest
machine id = 2C8724C00
number lps = 10
relocatable = n
strict = y
stripe width = 0
stripe size in exponent = 0
type =
upperbound = 32
fs = vfs=jfs2:log=/dev/loglv02:options=rw:account=false
time created = time modified = Sat Apr 11 13:35:27 2009
--type的信息无法恢复。time created的信息也无法恢复。 #mount /lvcbtest
#cd /lvcbtest
ls
config.xml lost+found webAppConfig.xml
#more config.xml
Provides the following main targets:
* installService: Installs Apache as service (on Windows only). Input
properties are:
--在异机恢复完成。在本机恢复LVCB的type信息是可以恢复的，我猜测因为ODM库有LVCB的部分信息，而同时VGDA也没有LVCB关于type的条目信息。
由于本人水平有限，错误之处，还望大家多多指点。
