ASM tools used by Support : KFOD, KFED, AMDU (Doc ID 1485597.1)

In this Document

Purpose

Scope

Details

1. KFOD - Kernel Files OSM Disk

2. KFED - Kernel Files metadata EDitor

3. AMDU - ASM Metadata Dump Utility

References

APPLIES TO:

Oracle Database - Enterprise Edition - Version 10.2.0.1 and later
Information in this document applies to any platform.

PURPOSE

This document is provided for educational purposes in order to have a general overview of ASM utilities: KFOD, KFED, AMDU .

Oracle Support may ask for additional or other specific information, depends on your case.

Note 1345068.1 - Files for Upload When Creating ASM/Storage Service Requests

SCOPE

 General overview of ASM utilities KFOD, KFED, AMDU usage.

DETAILS

1. KFOD - Kernel Files OSM Disk

KFOD utility is used to simulate the disk discovery from the operating system level and it can be found in $GRID_HOME/bin directory (or ASM_HOME/bin in older releases).

Note: 
1) KFOD is used at installation time as well (by OUI,DBCA or ASMCA) in order to perform disk discovery. 
2) In case of a failed installation (e.g no $GRID_HOME/bin existing yet) KFOD can be found under your stage folder: <stage_folder>/grid/stage/ext/bin/
In such cases you might need to set LD_LIBRARY_PATH to <stage_folder>/grid/stage/ext/lib.

Help screen can be seen using:

$> kfod help=y

_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' ...]
d/isks                                    Disks to discover [disks=raw,asm,all]
g/roup                                   Group discover [group=controlfile]
n/ohdr                                   KFOD header suppression [nohdr=TRUE/(FALSE)]
o/p                                        KFOD options type [OP=DISKS/GROUPS/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)]

 

 
The usual syntax used for disk discovery is:

kfod status=TRUE asm_diskstring='<your_path_to_ASM_devices>' disk=ALL

  

EXAMPLE

$ export LD_LIBRARY_PATH=/u01/stage/11.2.0.1/grid/stage/ext/lib
$ /u01/stage/11.2.0.1/grid/stage/ext/bin/kfod status=TRUE asm_diskstring='/dev/rdsk/*' disk=all dscvgroup=TRUE
--------------------------------------------------------------------------------
Disk Size Header Path Disk Group User Group
================================================================================
1: 10040 Mb MEMBER /dev/rdsk/c0t600144F0E08ACF0000004C2F6FBB0005d0s1  DG oracle oinstall
2: 10040 Mb MEMBER /dev/rdsk/c0t600144F0E08ACF0000004C2F6FBC0006d0s1  DG oracle oinstall
3: 10142 Mb MEMBER /dev/rdsk/c0t600144F0E08ACF0000004C2F6FBE0007d0s1  DG oracle oinstall
4: 10142 Mb MEMBER /dev/rdsk/c0t600144F0E08ACF0000004C2F6FBF0008d0s1  DG oracle oinstall
5:  9734 Mb MEMBER /dev/rdsk/c0t600144F0E08ACF0000004C2F6FC00009d0s1 FRA oracle oinstall 
--------------------------------------------------------------------------------

 

 

 2. KFED - Kernel Files metadata EDitor

KFED is a useful tool which allows to analyze ASM disk header information when ASM diskgroups can not be mounted.

Note 1180491.1 - KFED Tool For Windows OS. Note 1346190.1 - KFED.PL for diagnosing - ORA-15036 ORA-15042 ORA-15020 ORA-15033

NOTE:
KFED executable comes with installation from 11.1 onwards; for the older version you must build it.
But it is not included  the source of the software, therefore it is not available until GI installation completes.  
If you need to use it before GI being installed, please refer

Note 1505005.1 - Where to find kfed utility before Oracle Grid Infrastructure is installed

 

Help screen can be seen using:

$>kfed help=y

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] 

  

 The usual syntax used for reading ASM disk header is: 

$> kfed read <your_device>

  

 EXAMPLE:

$> kfed read /dev/raw/raw1
     
   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: T=0 NUMB=0x0
   kfbh.block.obj:                   2147483648 ; 0x008: TYPE=0x8 NUMB=0x0
   kfbh.check:                        2932902794 ; 0x00c: 0xaed08b8a
   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:         ORCLDISK ; 0x000: length=8
   kfdhdb.driver.reserved[0]:            0 ; 0x008: 0x00000000
   kfdhdb.driver.reserved[1]:            0 ; 0x00c: 0x00000000
   kfdhdb.driver.reserved[2]:            0 ; 0x010: 0x00000000
   kfdhdb.driver.reserved[3]:            0 ; 0x014: 0x00000000
   kfdhdb.driver.reserved[4]:            0 ; 0x018: 0x00000000
   kfdhdb.driver.reserved[5]:            0 ; 0x01c: 0x00000000
   kfdhdb.compat:                 168820736 ; 0x020: 0x0a100000
   kfdhdb.dsknum:                     0 ; 0x024: 0x0000
   kfdhdb.grptyp:                        1 ; 0x026: KFDGTP_EXTERNAL
   kfdhdb.hdrsts:                        3 ; 0x027: KFDHDR_MEMBER
   kfdhdb.dskname:               ASM01_0000 ; 0x028: length=10
   kfdhdb.grpname:               ASM01 ; 0x048: length=5
   kfdhdb.fgname:                 ASM01_0000 ; 0x068: length=10
   kfdhdb.capname:               ; 0x088: length=0
   kfdhdb.crestmp.hi:             32837774 ; 0x0a8: HOUR=0xe DAYS=0x4 MNTH=0x4 YEAR=0x7d4
   kfdhdb.crestmp.lo:             1555722240 ; 0x0ac: USEC=0x0 MSEC=0x29c SECS=0xb MINS=0x17
   kfdhdb.mntstmp.hi:            32837774 ; 0x0b0: HOUR=0xe DAYS=0x4 MNTH=0x4 YEAR=0x7d4
   kfdhdb.mntstmp.lo:            1563864064 ; 0x0b4: USEC=0x0 MSEC=0x1ab SECS=0x13 MINS=0x17
  ...
   kfdhdb.ub4spare[60]:         0 ; 0x1d0: 0x00000000
   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 

  

NOTES:

1) KFED returns a readable output only when devices are/were part of an ASM diskgroup.
Otherwise (if the device hasn't been added to a diskgroup yet or the disk is not valid anymore) the output looks like:

KFED-00322: Invalid content encountered during block traversal: [kfbtTraverseBlock][Invalid OSM block type][][0]

2) In case of a non-default AU size, you should specify it in the command:

$> kfed read <your_device> AUSZ=<au_size>

 

 

 3. AMDU - ASM Metadata Dump Utility

AMDU is an utility to extract all the available metadata from one or more ASM disks and/or generate formatted printouts of individual blocks.The utility does not require that any diskgroup to be mounted.

Oracle Support may ask you to provide AMDU output, especially when facing internal errors related to the ASM metadata

 

NOTE:
AMDU executable comes with installation from 11.1 onwards. Although this tool was released with 11g, it can be used with ASM 10g as well.

Note 553639.1 - Placeholder for AMDU binaries and using with ASM 10g  

The usual syntax used for dumping metadata related to a diskgroup is:

$> amdu -diskstring '<your_path_to_ASM_disks'  -dump  '<diskgroup>' 

NOTE:

Every time AMDU is executed a directory is created on the current location, unless it is override by parameter -directory.  
The directory will have the format amdu_YYYY_MM_DD_HH24_MM_SS

 

The default command  will generate following files:

<diskgroup>_0001.img     -  a exact dump of the content of the diskgroup ;size is limited to 2gb but can be more than one file
<diskgroup>.map            -  can be used to find the exact location of the ASM metadata on the disks
report.txt                        -  include details about the disks scanned

 

The report.txt file shows the header info of the disks belonging to diskgroup, like below:

EXAMPLE:

$> amdu -diskstring '/dev/raw/raw*' -dump 'DG11'

--------------------------------------------------------------------------------

<report.txt content>

----------------------------- DISK REPORT N0003 ---------------------------
Disk Path: /dev/raw/raw3 
Physical Sector Size: 512 bytes 
Disk Size: 977 megabytes 
Group Name: DG11 
Disk Name: DG11_0000 
Failure Group Name: DG11_0000

----------------------------- DISK REPORT N0004 ---------------------------
Disk Path: /dev/raw/raw4 
Physical Sector Size: 512 bytes 
Disk Size: 978 megabytes 
Group Name: DG11 
Disk Name: DG11_0001 
Failure Group Name: DG11_0001

....

  

CAUTION: DO NOT USE the above tools with options which can damage your disks, without Oracle Support guidance.