最近发现amdu命令比以前认知中的强大,记录下相关参数
[oracle@xifenfei ~]$ amdu help=y
a/usize AU size for corrupt disks
-ausize <bytes>: 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 <diskgroup>: 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 <bytes>: 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 <string>: 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 <string>: 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 <string>. 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 <diskgroup>: 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 <string>: 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 <diskgroup>.<file_number>: 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
<diskgroup>_<number>.f where <diskgroup> is the diskgroup name
in uppercase, and <number> 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 <file_name>: 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 <path_name>: 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 <block_spec>: This option prints one or more blocks to standard
out. This option may be specified multiple times to print multiple
<block_spec>s. The printout contains information about how each
block was read as well as a formatted printout. Multiple blocks
matching the same <block_spec> 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 <block_spec> may include
a count of sequential blocks to print. A <block_spec> may specify
a block either by disk or file.
<block_spec> ::= <single_block> | <single_block>.C<count>
<single_block> ::= <report_disk_block> | <group_disk_block> |
<extent_file_block> | <virtual_file_block> | <xmap_file_block>
<report_disk_block> ::=
<group_name>.N<report_number>.A<au_number>.B<block_number>
<group_disk_block> ::=
<group_name>.D<disk_number>.A<au_number>.B<block_number>
<extent_file_block> ::=
<group_name>.F<file_number>.X<physical_extent>.B<block_number>
<virtual_file_block> ::=
<group_name>.F<file_number>.V<virtual_block_number>
<xmap_file_block> ::=
<group_name>.F<file_number>.M<extent_map_block_number>
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