Reading ASM Headers using kfed

kfed is an oracle based utility to read ASM disk headers. kfed is not available by default. This needs to be relinked.

I found this tool particularly useful in:
a) Identifying if a particular raw device's disk headers were cleared before a raw device can be reused.
b) Identifying which raw device belongs to which diskgroup.
c) Identifying multiple paths to the same raw device. (Oracle instance complains if you have multiple paths to the same raw device, and the diskgroup does not mount)


cd $ORACLE_HOME/rdbms/lib
make -f ins_rdbms.mk ikfed

[oracle]$ kfed read /dev/raw/raw10

/dev/raw/raw10
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: 822661445 ; 0x00c: 0x3108d145
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: DATA_01_0000 ; 0x028: length=12
kfdhdb.grpname: DATA_01 ; 0x048: length=7
kfdhdb.fgname: DATA_01_0000 ; 0x068: length=12
kfdhdb.capname: ; 0x088: length=0
kfdhdb.crestmp.hi: 32932905 ; 0x0a8: HOUR=0x9 DAYS=0x1 MNTH=0x1 YEAR=0x7da
kfdhdb.crestmp.lo: 3835458560 ; 0x0ac: USEC=0x0 MSEC=0x31d SECS=0x9 MINS=0x39
kfdhdb.mntstmp.hi: 32932905 ; 0x0b0: HOUR=0x9 DAYS=0x1 MNTH=0x1 YEAR=0x7da
kfdhdb.mntstmp.lo: 3835458560 ; 0x0b4: USEC=0x0 MSEC=0x31d SECS=0x9 MINS=0x39
kfdhdb.secsize: 512 ; 0x0b8: 0x0200
kfdhdb.blksize: 4096 ; 0x0ba: 0x1000
kfdhdb.ausize: 1048576 ; 0x0bc: 0x00100000
kfdhdb.mfact: 113792 ; 0x0c0: 0x0001bc80
kfdhdb.dsksize: 131069 ; 0x0c4: 0x0001fffd
kfdhdb.pmcnt: 3 ; 0x0c8: 0x00000003
kfdhdb.fstlocn: 1 ; 0x0cc: 0x00000001
kfdhdb.altlocn: 2 ; 0x0d0: 0x00000002
kfdhdb.f1b1locn: 0 ; 0x0d4: 0x00000000
kfdhdb.redomirrors[0]: 0 ; 0x0d8: 0x0000
kfdhdb.redomirrors[1]: 0 ; 0x0da: 0x0000
kfdhdb.redomirrors[2]: 0 ; 0x0dc: 0x0000
kfdhdb.redomirrors[3]: 0 ; 0x0de: 0x0000
kfdhdb.dbcompat: 168820736 ; 0x0e0: 0x0a100000
kfdhdb.grpstmp.hi: 32932905 ; 0x0e4: HOUR=0x9 DAYS=0x1 MNTH=0x1 YEAR=0x7da
kfdhdb.grpstmp.lo: 3835427840 ; 0x0e8: USEC=0x0 MSEC=0x2ff SECS=0x9 MINS=0x39
kfdhdb.ub4spare[0]: 0 ; 0x0ec: 0x00000000
kfdhdb.ub4spare[1]: 0 ; 0x0f0: 0x00000000
kfdhdb.ub4spare[2]: 0 ; 0x0f4: 0x00000000
kfdhdb.ub4spare[3]: 0 ; 0x0f8: 0x00000000
kfdhdb.ub4spare[4]: 0 ; 0x0fc: 0x00000000
kfdhdb.ub4spare[5]: 0 ; 0x100: 0x00000000
kfdhdb.ub4spare[6]: 0 ; 0x104: 0x00000000
kfdhdb.ub4spare[7]: 0 ; 0x108: 0x00000000
kfdhdb.ub4spare[8]: 0 ; 0x10c: 0x00000000
kfdhdb.ub4spare[9]: 0 ; 0x110: 0x00000000
kfdhdb.ub4spare[10]: 0 ; 0x114: 0x00000000
kfdhdb.ub4spare[11]: 0 ; 0x118: 0x00000000
kfdhdb.ub4spare[12]: 0 ; 0x11c: 0x00000000
kfdhdb.ub4spare[13]: 0 ; 0x120: 0x00000000
kfdhdb.ub4spare[14]: 0 ; 0x124: 0x00000000
kfdhdb.ub4spare[15]: 0 ; 0x128: 0x00000000
kfdhdb.ub4spare[16]: 0 ; 0x12c: 0x00000000
kfdhdb.ub4spare[17]: 0 ; 0x130: 0x00000000
kfdhdb.ub4spare[18]: 0 ; 0x134: 0x00000000
kfdhdb.ub4spare[19]: 0 ; 0x138: 0x00000000
kfdhdb.ub4spare[20]: 0 ; 0x13c: 0x00000000
kfdhdb.ub4spare[21]: 0 ; 0x140: 0x00000000
kfdhdb.ub4spare[22]: 0 ; 0x144: 0x00000000
kfdhdb.ub4spare[23]: 0 ; 0x148: 0x00000000
kfdhdb.ub4spare[24]: 0 ; 0x14c: 0x00000000
kfdhdb.ub4spare[25]: 0 ; 0x150: 0x00000000
kfdhdb.ub4spare[26]: 0 ; 0x154: 0x00000000
kfdhdb.ub4spare[27]: 0 ; 0x158: 0x00000000
kfdhdb.ub4spare[28]: 0 ; 0x15c: 0x00000000
kfdhdb.ub4spare[29]: 0 ; 0x160: 0x00000000
kfdhdb.ub4spare[30]: 0 ; 0x164: 0x00000000
kfdhdb.ub4spare[31]: 0 ; 0x168: 0x00000000
kfdhdb.ub4spare[32]: 0 ; 0x16c: 0x00000000
kfdhdb.ub4spare[33]: 0 ; 0x170: 0x00000000
kfdhdb.ub4spare[34]: 0 ; 0x174: 0x00000000
kfdhdb.ub4spare[35]: 0 ; 0x178: 0x00000000
kfdhdb.ub4spare[36]: 0 ; 0x17c: 0x00000000
kfdhdb.ub4spare[37]: 0 ; 0x180: 0x00000000
kfdhdb.ub4spare[38]: 0 ; 0x184: 0x00000000
kfdhdb.ub4spare[39]: 0 ; 0x188: 0x00000000
kfdhdb.ub4spare[40]: 0 ; 0x18c: 0x00000000
kfdhdb.ub4spare[41]: 0 ; 0x190: 0x00000000
kfdhdb.ub4spare[42]: 0 ; 0x194: 0x00000000
kfdhdb.ub4spare[43]: 0 ; 0x198: 0x00000000
kfdhdb.ub4spare[44]: 0 ; 0x19c: 0x00000000
kfdhdb.ub4spare[45]: 0 ; 0x1a0: 0x00000000
kfdhdb.ub4spare[46]: 0 ; 0x1a4: 0x00000000
kfdhdb.ub4spare[47]: 0 ; 0x1a8: 0x00000000
kfdhdb.ub4spare[48]: 0 ; 0x1ac: 0x00000000
kfdhdb.ub4spare[49]: 0 ; 0x1b0: 0x00000000
kfdhdb.ub4spare[50]: 0 ; 0x1b4: 0x00000000
kfdhdb.ub4spare[51]: 0 ; 0x1b8: 0x00000000
kfdhdb.ub4spare[52]: 0 ; 0x1bc: 0x00000000
kfdhdb.ub4spare[53]: 0 ; 0x1c0: 0x00000000
kfdhdb.ub4spare[54]: 0 ; 0x1c4: 0x00000000
kfdhdb.ub4spare[55]: 0 ; 0x1c8: 0x00000000
kfdhdb.ub4spare[56]: 0 ; 0x1cc: 0x00000000
kfdhdb.ub4spare[57]: 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


If a disk is not an ASM DISK, Then the header would look something like:

[oracle]$ kfed read /dev/raw/raw1
kfbh.endian: 0 ; 0x000: 0x00
kfbh.hard: 0 ; 0x001: 0x00
kfbh.type: 0 ; 0x002: KFBTYP_INVALID
kfbh.datfmt: 0 ; 0x003: 0x00
kfbh.block.blk: 0 ; 0x004: T=0 NUMB=0x0
kfbh.block.obj: 0 ; 0x008: TYPE=0x0 NUMB=0x0
kfbh.check: 0 ; 0x00c: 0x00000000
kfbh.fcn.base: 0 ; 0x010: 0x00000000
kfbh.fcn.wrap: 0 ; 0x014: 0x00000000
kfbh.spare1: 0 ; 0x018: 0x00000000
kfbh.spare2: 0 ; 0x01c: 0x00000000
[oracle]$