ASM管理命令行三工具：KFOD、KFED和AMDU
ASM（Automatic Storage Management）是Oracle目前主推的软集群存储策略。一般而言，管理ASM的工具包括使用sqlplus命令行、ASMCA图形化界面。此外，ASM Disk的配置和创建，可以通过oracleasm程序命令行进行配置。进入11g之后，集群件GI的crsctl和srvctl也可以提供ASM实例Instance和Disk Group级别的修改。
一般情况下，ASM安装管理借助上述工具就够了，况且Oracle Restate和Cluster ware可以确保ASM组建的HA架构。
一些特殊场景，如磁盘数据损坏、底层修复和ASM盘发现，需要额外的一些命令行工具。ASM工具包括：kfod、kfed和AMDU。在早期的ASM版本（10gR2）中，一部分工具还需要额外的重新编译和链接才能使用。在11g，这部分工具已经成为默认设置，可以直接使用。
本篇主要介绍三个工具的基本使用和功能介绍。
1、kfod工具
与图形化界面不同，kfod属于底层的功能命令行工具。最常用的场景是从操作系统层面刺激磁盘的扫描动作，用于辅助ASM发现可用的ASM DISK。Oracle官方门户中，对于kfod的描述包括如下几个方面：
ü Oracle ASM和Database安装过程中，kfod是会自动被调用，用于进行磁盘发现过程（Disk Discovery）；
ü 如果在安装Grid过程没有成功，kfod也会在安装stage文件夹中被找到。目录地址为：/grid/stage/ext/bin/。如果有这样的情况，Oracle就要求我们设置环境变量LD_LIBRARY_PATH到/grid/stage/ext/bin/；
简单的说，kfod查看检索的意义更大，并不像其他有破坏性工具那样存在很大风险。使用帮助命令参数，可以看到kfod的功能说明。
[grid@NCR-Standby-Asm ~]$ kfod help
KFOD-00101: LRM error [107] while parsing command line arguments
_asm_a/llow_only_raw_disks KFOD allow only raw devices [_asm_allow_only_raw_disks=TRUE/(FALSE)]
_asm_l/ibraries ASM Libraries[_asm_libraries=lib1,lib2,...]
_asms/id ASM Instance[_asmsid=sid]
a/sm_diskstring ASM Diskstring [asm_diskstring=discoverystring, discoverystring ...]
c/luster KFOD cluster [cluster=TRUE/(FALSE)]
db/_unique_name db_unique_name for ASM instance[db_unique_name=dbname]
di/sks Disks to discover [disks=raw,asm,badsize,all]
ds/cvgroup Include group name [dscvgroup=TRUE/(FALSE)]
g/roup Disks in diskgroup [group=diskgroup]
h/ostlist hostlist[hostlist=host1,host2,...]
metadata_a/usize AU Size for Metadata Size Calculation
metadata_c/lients Client Count for Metadata Size Calculation
metadata_d/isks Disk Count for Metadata Size Calculation
metadata_n/odes Node Count for Metadata Size Calculation
metadata_r/edundancy Redundancy for Metadata Size Calculation
n/ohdr KFOD header suppression [nohdr=TRUE/(FALSE)]
o/p KFOD options type [OP=DISKS/CANDIDATES/MISSING/GROUPS/INSTS/VERSION/CLIENTS/RM/RMVERS/DFLTDSTR/GPNPDSTR/METADATA/ALL]
p/file ASM parameter file [pfile=parameterfile]
s/tatus Include disk header status [status=TRUE/(FALSE)]
v/erbose KFOD verbose errors [verbose=TRUE/(FALSE)]
几个常见的操作方法：
--查看ASM配置基本情况
[grid@NCR-Standby-Asm ~]$ kfod
--------------------------------------------------------------------------------
ORACLE_SID ORACLE_HOME
================================================================
+ASM /u01/app/grid/product/11.2.0/grid
--查看ASM Disk情况
[grid@NCR-Standby-Asm ~]$ kfod di=all
--------------------------------------------------------------------------------
Disk Size Path User Group
================================================================================
1: 20489 Mb ORCL:DATA1
2: 20489 Mb ORCL:DATA2
3: 20489 Mb ORCL:DATA3
4: 20489 Mb ORCL:DATA5
5: 20442 Mb ORCL:DATA6
--------------------------------------------------------------------------------
ORACLE_SID ORACLE_HOME
================================================================================
+ASM /u01/app/grid/product/11.2.0/grid
--特定diskgroup情况
[grid@NCR-Standby-Asm ~]$ kfod status=true g=data
--------------------------------------------------------------------------------
Disk Size Path
================================================================================
0 20489 Mb ORCL:DATA1
1 20489 Mb ORCL:DATA2
2 20489 Mb ORCL:DATA3
[grid@NCR-Standby-Asm ~]$ kfod status=true g=reco
--------------------------------------------------------------------------------
Disk Size Path
================================================================================
0 20489 Mb ORCL:DATA5
1 20442 Mb ORCL:DATA6
2、KFED
KFED的全称为Kernel File Metadata Editor。KFED的使用场景比较严峻，就是当ASM Diskgroup不能成功mount的时候，通过KFED来分析ASM磁盘头信息，来诊断问题。
从Oracle 11.1开始，KFED就已经正式成为安装组件的一部分。一些旧的版本中，就需要手工进行build构建。与Kfod的区别是，KFED只有在完全安装完之后，才能使用，在stage阶段无法使用。
KFED帮助信息如下：
[grid@NCR-Standby-Asm ~]$ kfed
as/mlib ASM Library [asmlib='lib']
aun/um AU number to examine or update [AUNUM=number]
aus/z Allocation Unit size in bytes [AUSZ=number]
blkn/um Block number to examine or update [BLKNUM=number]
blks/z Metadata block size in bytes [BLKSZ=number]
ch/ksum Update checksum before each write [CHKSUM=YES/NO]
cn/t Count of AUs to process [CNT=number]
de/v ASM device to examine or update [DEV=string]
dm/pall Don't suppress repeated lines when dumping corrupt blocks [DMPALL=YES/NO]
o/p KFED operation type [OP=READ/WRITE/MERGE/REPAIR/NEW/FORM/FIND/STRUCT]
p/rovnm Name for provisioning purposes [PROVNM=string]
s/eek AU number to seek to [SEEK=number]
te/xt File name for translated block text [TEXT=string]
ty/pe ASM metadata block type number [TYPE=number]
最常用的场景，是借助kfed去读ASM Disk的磁盘头信息。
[grid@NCR-Standby-Asm ~]$ kfed read /dev/sdb1
KFED-00303: unable to open file '/dev/sdb1'
[grid@NCR-Standby-Asm ~]$ env | grep ORACLE_HOME
ORACLE_HOME=/u01/app/grid/product/11.2.0/grid
[root@NCR-Standby-Asm ~]# cd /u01/app/grid/product/11.2.0/grid
[root@NCR-Standby-Asm grid]# cd bin/
[root@NCR-Standby-Asm bin]# ls -l | grep kfed
-rwxr-x--x 1 grid oinstall 2403791 May 25 15:28 kfed
-rwxr-x--x 1 grid oinstall 2403783 May 5 09:21 kfedO
[root@NCR-Standby-Asm bin]# ./kfed read /dev/sdb1
kfbh.endian: 1 ; 0x000: 0x01
kfbh.hard: 130 ; 0x001: 0x82
kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD
kfbh.datfmt: 1 ; 0x003: 0x01
kfbh.block.blk: 0 ; 0x004: blk=0
kfbh.block.obj: 2147483648 ; 0x008: disk=0
kfbh.check: 586307481 ; 0x00c: 0x22f25799
kfbh.fcn.base: 0 ; 0x010: 0x00000000
kfbh.fcn.wrap: 0 ; 0x014: 0x00000000
kfbh.spare1: 0 ; 0x018: 0x00000000
（篇幅原因，有省略……）
kfdhdb.acdb.aba.seq: 0 ; 0x1d4: 0x00000000
kfdhdb.acdb.aba.blk: 0 ; 0x1d8: 0x00000000
kfdhdb.acdb.ents: 0 ; 0x1dc: 0x0000
kfdhdb.acdb.ub2spare: 0 ; 0x1de: 0x0000
针对ASM Disk头块损坏的问题，Oracle推出了自动backup策略，备份块就在510位置上。
[root@NCR-Standby-Asm bin]# ./kfed read /dev/sdb1 blkn=510
kfbh.endian: 1 ; 0x000: 0x01
kfbh.hard: 130 ; 0x001: 0x82
kfbh.type: 1 ; 0x002: KFBTYP_DISKHEAD
kfbh.datfmt: 1 ; 0x003: 0x01
kfbh.block.blk: 254 ; 0x004: blk=254
kfbh.block.obj: 2147483648 ; 0x008: disk=0
kfbh.check: 586307431 ; 0x00c: 0x22f25767
kfbh.fcn.base: 0 ; 0x010: 0x00000000
kfbh.fcn.wrap: 0 ; 0x014: 0x00000000
kfbh.spare1: 0 ; 0x018: 0x00000000
kfbh.spare2: 0 ; 0x01c: 0x00000000
kfdhdb.driver.provstr: ORCLDISKDATA1 ; 0x000: length=13
自动命令repair，也就是将这个块的信息写回到头块位置上。
3、AMDU
AMDU是笔者个人觉得最像是官方工具的一个，全称为：ASM Metadata Dump Utility。AMDU最大的作用在于可以将ASM Disk Group和DISK所有可用元数据信息导出，并且整理为可读的格式内容。
AMDU最大的一个好处，在于其工作不受到Disk Group是否mount访问的影响。这个工具之所以被正式公布，主要在于Oracle Support在进行远程支持的时候，需要客户提供上载文件。
工具帮助参数信息如下：
[grid@NCR-Standby-Asm ~]$ amdu help=y
a/usize AU size for corrupt disks
-ausize : This option must be set when -baddisks is set. It
must be a power of 2. This size is required to scan a disk looking
for metadata, and it is normally read from the disk header. The
value applies to all disks that do not have a valid header. The
value from the disk header will be used if a valid header is
found.
ba/ddisks Include disks with bad headers
-baddisks : Normally disks with bad disk headers, or that
look like they were never part of a disk group, will not be
scanned. This option forces them to be scanned anyway and to be
considered part of the given diskgroup. This is most useful when
a disk header has been damaged. The disk will still need to have
a valid allocation table to drive the scan unless -fullscan is
used. In any case at least one block in the first two AUs must be
valid so that the disk number can be determined. The options
-ausize and -blksize are required since these values are normally
fetched from the disk header. If the diskgroup uses external
redundancy then -external should be specified. These values will
be compared against any valid disks found in the diskgroup and
they must be the same.
bl/ksize ASM block size for corrupt disks
-blksize : This option must be set when -baddisks is set. It
must be a power of 2. This size is required to scan a disk looking
for metadata, and it is normally read from the disk header. The
value applies to all disks that do not have a valid header. The
value from the disk header will be used if a valid header is
found.
c/ompare Compare file mirrors
-compare: This option only applies to file extraction from a normal or
high redundancy disk group. Every extent that is mirrored on more
than one discovered disk will have all sides of its mirror
compared. If they are not identical a message will be reported
on standard error and the report file. The message will indicate
which copy was extracted. A count of the blocks that are not
identical will be in the report file.
dir/ectory Directory from previous dump
-directory : This option completely eliminates the discovery
phase of operation. It specifies the name of a dump directory from
a previous run of AMDU. The report file and map files are read
instead of doing a discovery and scan. The parsing of these ASCII
files is very dependent on them being exactly as written by AMDU.
AMDU is unlikely to work properly if they have been modified by
a text editor, or if some of the files are missing or truncated.
Note that the directory may be a copy FTPed from another
machine. The other machine may even be a different platform
with a different endianess.
dis/kstring Diskstring for discovery
-diskstring : By default the null string is used for
discovery. The null string should discover all disks the user has
access to. Many installations specify an asm_diskstring parameter
for their ASM instance. If so that parameter value should be given
here. Multiple discovery strings can be specified by multiple
occurrences of -diskstring . Beware of shell syntax
conflicts with discovery strings. Diskstrings are usually the same
syntax the shell uses for expanding path names on command lines so
they will most likely need to be enclosed in single quotes.
du/mp Diskgroups to dump
-dump : This option specifies the name of a diskgroup to
have its metadata dumped. This option may be specified multiple
times to dump multiple diskgroups. If the diskgroup name is ALL
then all diskgroups encountered will be dumped. The diskgroup name
is not case sensitive, but will be converted to uppercase for all
reports. If this option is not specified then no map or image
files will be created, but -extract and -print may still work.
exc/lude Disks to exclude
-exclude : Multiple exclude options may be specified. These
strings are used for discovery just like the values for diskstring.
Only shallow discovery is done on these diskstrings. Any disks
found in the exclude discovery will not be accessed. If they are
also discovered using the -diskstring strings, then the report will
include the information from shallow discovery along with a message
indicating the disk was excluded.
exte/rnal Assume external redundancy
-external: Normally AMDU determines the diskgroup redundancy from the
disk headers. However this is not possible with the -baddisks
option. It is assumed that the redundancy of the -baddisks
diskgroup is normal or high unless this option is given to specify
external redundancy.
extr/act Files to extract
-extract .: This extracts the numbered file
from the named diskgroup, case insensitive. This option may be
specified multiple times to extract multiple files. The extracted
file is placed in the dump directory under the name
_.f where is the diskgroup name
in uppercase, and is the file number. The -output option
may be used to write the file to any location. The extracted file
will appear to have the same contents it would have if accessed
through the database. If some portion of the file is unavailable
then that portion of the output file will be filled with
0xBADFDA7A, and a message will appear on stderr.
fi/ledump Dump files rather than extract
-filedump: This option causes the file objects in the command line to
have their blocks dumped to the image files rather than extracted.
This can be combined with the -novirtual option to selectively
dump only some of the metadata files. It may also be used to dump
user files (number >= 256) so that all mirrored copies can be
examined.
fo/rmer Include dropped disks
-former: Normally disks marked as former are not scanned, but this
option will scan them and include their contents in the output.
This is useful when it is necessary to look at the contents of a
disk that was dropped. Note that dropped normal disks will not have
any entries in their allocation tables and thus only the physically
addressed extents will be dumped. Force dropped disks will not have
status former in their disk headers and are not affected by this
option. However if DROP DISKGROUP is used, the disks will have the
contents as of the time of the drop, and will be in status former.
Thus this option is useful for extracting files from a dropped
diskgroup.
fu/llscan Scan entire disk
-fullscan: This option reads every AU on the disk and looks at the
contents of the AU rather than limiting the AU's read based on the
allocation table. This is useful when the allocation table is
corrupt or needs recovery. An AU will be written to the image file
if it starts with a block that contains a valid ASM block header.
The file and extent information for the map will be extracted from
the block header. Physically addressed metadata will be dumped
regardless of its contents. This option is incompatible with
extracting a file. It is an error to specify -extract with this
option. Note that this option is likely to find old garbage
metadata in unallocated AU's since there is no means of
determining what is allocated. Thus there may be many different
copies of the same block, possibly of different versions.
h/ex Always print block contents in hex
-hex: This prints the block contents in hex without attempting to print
them as ASM metadata. This is useful when the block is known to not
be ASM metadata. It avoids the ASM block header dump and ensures
the block is not accidentally interpreted as ASM metadata. This
option requires at least one -print option.
noa/cd Do not dump ACD
-noacd: This option limits the dumping of the Active Change Directory
to just the control blocks that contain the checkpoint. There is
126 MB of ACD per ASM instance (42 MB for external redundancy). It
is normally of no interest if there has been a clean shutdown or
no updates for a while. This option avoids dumping a lot of
unimportant data. The blocks will still be read and checked for
corruption. The map file will still contain entries for the ACD
extents, but the block counts will be zero.
nod/ir Do not create a dump directory
-nodir: No dump directory is created, and no files are created in it.
The directory name is not written to standard out. The report file
is written to standard out before any block printouts from any
-print options. This option conflicts with -filedump. It is an
error to specify this and extract a file to the dump directory.
noe/xtract Do not create extracted file
-noextract: This prevents files from being extracted to an output
file, but the file will be read and any errors in selecting the
correct output will be reported. This is most useful in
combination with the -compare option.
noh/eart Do not check for heartbeat
-noheart: Normally the heartbeat block will be saved at discovery time
and checked when the disk is scanned. A sleep is added between
discovery and scanning to ensure there is time for the heartbeat
to be written. If the heartbeat block changes then it is most
likely that the diskgroup containing this disk is mounted by an
active ASM instance. An error and warning is generated but
operation proceeds normally. This option suppresses this check
and avoids the sleep.
noi/mage Do not create image files
-noimage: No image files will be created n the dump directory. All
the reads specified by the read options will still be done. The
map files may be used to find blocks on the disks themselves. In
the map file, the count of blocks dumped, the image file sequence
number, and the byte offset in the image file will all always be
zero (C00000 S0000 B0000000000)
nom/ap Do not create map or image files
-nomap: No map file is created and no image file is created. The only
output is the report file. The -noimage option is assumed if this
is set since an image file without a map is useless. The options
-noscan and -noread also result in no map or image files, but
-nomap still reads the metadata to check for I/O errors and corrupt
blocks.
nop/rint Do no print block contents
-noprint: This suppresses the printout of the block contents for
blocks printed with the -print option. It is useful for getting
just the block reports without a lot of data. This option requires
at least one -print option.
norea/d Shallow discovery only
-noread: This eliminates any reading of any disks at all. Only shallow
discovery will be done. The report will end after the discovery
section. It is an error to specify this option and specify a file
to extract or blocks to print. It is an error to specify this
and -fullscan.
norep/ort Do not generate a report
-noreport: This suppresses the generation of the report file. It is
most useful in combination with -nodir and -print to get block
printouts without a lot of clutter. It is unnecessary to include
this with -directory since no report is generated then anyway.
nosc/an Deep discovery only
-noscan: This eliminates any reading of any disks after deep
discovery. This results in just doing a deep discovery using the
disksting parameter. The report will end after the discovery
section. It is an error to specify this option and specify a file
to extract. It is an error to specify this and -fullscan.
nosu/bdir Do not create a dump directory
-nosubdir: No dump directory is created, but files are still created.
The directory name is not written to standard out. The report file
and any other dump or extract files are written to the current
directory or to the directory indicated by -parentdir. This means
that if multiple AMDU dumps are requested using this option, the
report file will always correspond to the last dump requested.
nov/irtual Do not dump virtual metadata
-novirtual: This option eliminates reading of any virtual metadata.
Only the physically addressed metadata will be read. This
implicitly eliminates the ACD and extent maps so -noacd and
-noxmap will be assumed.
nox/map Do not dump extent maps
-noxmap: This option eliminates reading of the indirect extents
containing the file extent maps. This is the bulk of the metadata
in most diskgroups. Even the entries in the map file will be
eliminated.
o/utput Files to create for extract
-output : This option specifies a different file for
writing an extracted file. The file will be overwritten if it
already exists. This option requires that exactly one file is
extracted via the -extract option.
pa/rent Parent for dump directory
-parent : By default the dump directory is created in the
current directory, but another directory can be specified using
this option. The parent directory for the dump directory must
already exist.
pr/int Block to print
-print : This option prints one or more blocks to standard
out. This option may be specified multiple times to print multiple
s. The printout contains information about how each
block was read as well as a formatted printout. Multiple blocks
matching the same may be found when scanning the
disks. For example there may be multiple disks that have headers
for the same diskgroup and disk number. If the block is from a
mirrored file then multiple copies should exist on different disks.
If multiple copies of the same block have identical contents then
only one formatted printout of the contents will be generated, but
a header will be printed for each copy. A may include
a count of sequential blocks to print. A may specify
a block either by disk or file.
::= | .C
::= | |
| |
::=
.N.A.B
::=
.D.A.B
::=
.F.X.B
::=
.F.V
::=
.F.M
r/egistry Dump registry files
-registry: The ASM registries will be read and dumped to the image
file. There will be no block consistency checks since these files
do not have ASM cache headers. To dump one specific registry
specify -filedump and include the file object for the registry
(e.g. DATA.255).
s/pfile Extract usable spfile
-spfile: This causes extract to render the resulting file in a form
that is directly usable by startup. Without this option, AMDU
will extract the file as a regular ASM file including all ASM
specific headers and such
每次执行amdu命令，就会在当前目录上创建出一个带有当前时间信息的文件夹结构。
[grid@NCR-Standby-Asm ~]$ amdu
amdu_2015_06_05_10_15_47/
[grid@NCR-Standby-Asm ~]$ ls -l | grep amdu
drwxr-xr-x 2 grid oinstall 4096 Jun 5 10:15 amdu_2015_06_05_10_15_47
进入其中，可以查看report.txt文件，作为信息收集结果。
[grid@NCR-Standby-Asm ~]$ cd amdu_2015_06_05_10_15_47/
[grid@NCR-Standby-Asm amdu_2015_06_05_10_15_47]$ ls -l
total 8
-rw-r--r-- 1 grid oinstall 5350 Jun 5 10:15 report.txt
[grid@NCR-Standby-Asm amdu_2015_06_05_10_15_47]$ more report.txt
-*-amdu-*-
******************************* AMDU Settings ********************************
ORACLE_HOME = /u01/app/grid/product/11.2.0/grid
System name: Linux
Node name: NCR-Standby-Asm
Release: 2.6.32-431.el6.x86_64
Version: #1 SMP Sun Nov 10 22:19:54 EST 2013
Machine: x86_64
amdu run: 05-JUN-15 10:15:47
Endianess: 1
--------------------------------- Operations ---------------------------------
------------------------------- Disk Selection -------------------------------
-diskstring ''
------------------------------ Reading Control -------------------------------
------------------------------- Output Control -------------------------------
********************************* DISCOVERY **********************************
----------------------------- DISK REPORT N0001 ------------------------------
Disk Path: ORCL:DATA1
Unique Disk ID:
Disk Label: DATA1
Physical Sector Size: 512 bytes
Disk Size: 20489 megabytes
Group Name: DATA
Disk Name: DATA1
Failure Group Name: DATA1
Disk Number: 0
Header Status: 3
Disk Creation Time: 2015/05/05 09:27:12.410000
Last Mount Time: 2015/06/01 08:45:51.489000
Compatibility Version: 0x0b200000(11020000)
Disk Sector Size: 512 bytes
Disk size in AUs: 20489 AUs
Group Redundancy: 1
Metadata Block Size: 4096 bytes
AU Size: 1048576 bytes
Stride: 113792 AUs
Group Creation Time: 2015/05/05 09:27:12.333000
File 1 Block 1 location: AU 2
OCR Present: NO
（篇幅原因，略……）
通过加入参数，可以实现转储特定Disk Group的内部信息。
[grid@NCR-Standby-Asm ~]$ cd /dev/oracleasm/disks/
[grid@NCR-Standby-Asm disks]$ ls -l
total 0
brw-rw---- 1 grid asmadmin 8, 17 May 22 16:57 DATA1
brw-rw---- 1 grid asmadmin 8, 18 May 22 16:57 DATA2
brw-rw---- 1 grid asmadmin 8, 19 May 22 16:57 DATA3
brw-rw---- 1 grid asmadmin 8, 21 May 22 16:57 DATA5
brw-rw---- 1 grid asmadmin 8, 22 May 22 16:57 DATA6
[grid@NCR-Standby-Asm oracleasm]$ cd ~
[grid@NCR-Standby-Asm ~]$ amdu -diskstring '/dev/oracleasm/disks/DATA*' -dump 'DATA'
amdu_2015_06_05_10_22_11/
[grid@NCR-Standby-Asm ~]$ cd amdu_2015_06_05_10_22_11/
[grid@NCR-Standby-Asm amdu_2015_06_05_10_22_11]$ ls -l
total 60448
-rw-r--r-- 1 grid oinstall 61882368 Jun 5 10:22 DATA_0001.img
-rw-r--r-- 1 grid oinstall 5360 Jun 5 10:22 DATA.map
-rw-r--r-- 1 grid oinstall 7325 Jun 5 10:22 report.txt
新增加文件，为Disk Group DATA的映射信息。
[grid@NCR-Standby-Asm amdu_2015_06_05_10_22_11]$ more DATA.map
N0001 D0000 R00 A00000000 F00000000 I0 E00000000 U00 C00256 S0001 B0000000000
N0001 D0000 R00 A00000001 F00000000 I0 E00000000 U00 C00256 S0001 B0001048576
N0001 D0000 R00 A00000002 F00000001 I0 E00000000 U00 C00256 S0001 B0002097152
N0001 D0000 R00 A00000003 F00000003 I0 E00000000 U00 C00256 S0001 B0003145728
N0001 D0000 R00 A00000004 F00000003 I0 E00000003 U00 C00256 S0001 B0004194304
N0001 D0000 R00 A00000005 F00000003 I0 E00000006 U00 C00256 S0001 B0005242880
使用-extract命令，可以直接从ASM Disk Group中抽取文件。
SQL> show parameter control
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
control_file_record_keep_time integer 7
control_files string +DATA/sicsstb/controlfile/current.260.878897845, +RECO/sicsstb/controlfile/current.256.878897845
control_management_pack_access string DIAGNOSTIC+TUNING
尝试抽取出控制文件。
[grid@NCR-Standby-Asm ~]$ amdu -extract DATA.260
amdu_2015_06_05_10_27_46/
AMDU-00204: Disk N0001 is in currently mounted diskgroup DATA
AMDU-00201: Disk N0001: 'ORCL:DATA1'
关闭实例和ASM。
[grid@NCR-Standby-Asm ~]$ srvctl stop database -d sicsstb
[grid@NCR-Standby-Asm ~]$ srvctl stop asm -f
[grid@NCR-Standby-Asm ~]$ amdu -extract DATA.260
amdu_2015_06_05_10_29_25/
[grid@NCR-Standby-Asm ~]$
抽取成功，进入目录。以ASCII格式打开control file。
[grid@NCR-Standby-Asm ~]$ cd amdu_2015_06_05_10_29_25/
[grid@NCR-Standby-Asm amdu_2015_06_05_10_29_25]$ ls -l
total 9528
-rw-r--r-- 1 grid oinstall 9748480 Jun 5 10:29 DATA_260.f
-rw-r--r-- 1 grid oinstall 7971 Jun 5 10:29 report.txt
[grid@NCR-Standby-Asm amdu_2015_06_05_10_29_25]$ strings DATA_260.f | grep +DATA
+DATA/sicsstb/onlinelog/group_3.263.878897849
+DATA/sicsstb/onlinelog/group_2.262.878897849
+DATA/sicsstb/onlinelog/group_1.261.878897847
+DATA/sicsstb/datafile/users.259.878897773
+DATA/sicsstb/datafile/undotbs1.258.878897773
+DATA/sicsstb/datafile/sysaux.257.878897773
+DATA/sicsstb/datafile/system.256.878897771
+DATA/sicsstb/tempfile/temp.264.878897855
+DATA/sicsstb/datafile/example.265.878897857
+DATA/sicsstb/onlinelog/group_3.263.878897849
+DATA/sicsstb/onlinelog/group_2.262.878897849
+DATA/sicsstb/onlinelog/group_1.261.878897847
+DATA/sicsstb/datafile/users.259.878897773
+DATA/sicsstb/datafile/undotbs1.258.878897773
+DATA/sicsstb/datafile/sysaux.257.878897773
+DATA/sicsstb/datafile/system.256.878897771
+DATA/sicsstb/tempfile/temp.264.878897855
+DATA/sicsstb/datafile/example.265.878897857
+DATA/sicsstb/datafile/example.265.878897857
[grid@NCR-Standby-Asm amdu_2015_06_05_10_29_25]$ strings DATA_260.f | grep +RECO
+RECO/sicsstb/onlinelog/group_3.259.878897849
+RECO/sicsstb/onlinelog/group_2.258.878897849
+RECO/sicsstb/onlinelog/group_1.257.878897849
+RECO/sicsstb/onlinelog/group_3.259.878897849
+RECO/sicsstb/onlinelog/group_2.258.878897849
+RECO/sicsstb/onlinelog/group_1.257.878897849
后续的恢复过程就容易了~
4、结论
Grid、ASM对于初学者是很头疼的，主要在于高度的自动化让很多人觉得神秘不可接近。“知识可以消除迷信”，在这样的情况下，我们要抱着更加虚心的态度去学习新技术和新工具，才能跟上时代，不断前进。