I made an error when creating an Oracle ASM disk group which resulted in not being able to drop or mount the disk group because the ASM header_status was FORMER. The following steps were performed to modify the ASM header_status from FORMER to MEMBER for version 12.1.0.2.0. Mounting and dropping disk group failed.
SQL> drop diskgroup ACFS_DATA;
drop diskgroup ACFS_DATA
*
ERROR at line 1:
ORA-15039: diskgroup not dropped
ORA-15001: diskgroup "ACFS_DATA" does not exist or is not mounted
SQL> alter diskgroup ACFS_DATA mount;
alter diskgroup ACFS_DATA mount
*
ERROR at line 1:
ORA-15032: not all alterations performed
ORA-15017: diskgroup "ACFS_DATA" cannot be mounted
ORA-15040: diskgroup is incomplete
SQL>
Review ASM disks. Note header_status is FORMER and group# is 0 (does not belong to group).
SQL> SELECT group_number group#, disk_number disk#, header_status header_, mode_status mode_, state, library, os_mb, total_mb, free_mb, label, path
2 FROM V$ASM_DISK
3 ORDER BY header_status desc, path
4 ;
GROUP# DISK# HEADER_ MODE_ STATE LIBRARY OS_MB TOTAL_MB FREE_MB LABEL PATH
------ ----- ---------- ---------- ------------ ---------------------------- ---------- ---------- ---------- --------------- ----------------------------------------
0 1 FORMER ONLINE NORMAL System 153584 0 0 /dev/mapper/acfs_01p1
22 rows selected.
Let's fix the issue.
Documentation used head -25 and might be better to grep for kfdhdb.hdrsts ### Use kfed to read device and confirm header_status KFDHDR_FORMER
$ kfed read '/dev/mapper/acfs_01p1' | head -25
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: 1999457674 ; 0x00c: 0x772d4d8a
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: 202375168 ; 0x020: 0x0c100000
kfdhdb.dsknum: 0 ; 0x024: 0x0000
kfdhdb.grptyp: 1 ; 0x026: KFDGTP_EXTERNAL
**********************************************************************
kfdhdb.hdrsts: 4 ; 0x027: KFDHDR_FORMER
**********************************************************************
kfdhdb.dskname: ACFS_DATA_0000 ; 0x028: length=14
kfdhdb.grpname: ACFS_DATA ; 0x048: length=9
kfdhdb.fgname: ACFS_DATA_0000 ; 0x068: length=14
### Backup device
$ mkdir -p /tmp/asm
$ dd if=/dev/mapper/acfs_01p1 of=/tmp/asm/ihotelp1_acfs.dmp bs=1048576 count=50
50+0 records in
50+0 records out
52428800 bytes (52 MB) copied, 0.303025 s, 173 MB/s
### Create template for patching device
$ kfed read /dev/mapper/acfs_01p1 > /tmp/asm/patch_acfs_01p1.txt
### Create copy of template for comparison
$ cp patch_acfs_01p1.txt patch_acfs_01p1.orig
### Edit patch_acfs_01p1.txt and change "kfdhdb.hdrsts: 4 ; 0x027: KFDHDR_FORMER" to "kfdhdb.hdrsts: 3 ; 0x027: KFDHDR_MEMBER"
### Verify change.
$ diff patch_acfs_01p1.txt patch_acfs_01p1.orig
< kfdhdb.hdrsts: 3 ; 0x027: KFDHDR_MEMBER --- > kfdhdb.hdrsts: 4 ; 0x027: KFDHDR_FORMER
### Patch device acfs_01p1 using patch_acfs_01p1.txt
$ kfed merge /dev/mapper/acfs_01p1 text=patch_acfs_01p1.txt
### Verify device acfs_01p1 is updated`
$ kfed read /dev/mapper/acfs_01p1 | grep kfdhdb.hdrsts
kfdhdb.hdrsts: 3 ; 0x027: KFDHDR_MEMBER
$
Verify results using SQL
SQL> SELECT group_number group#, disk_number disk#, header_status header_, mode_status mode_, state, library, os_mb, total_mb, free_mb, label, path
2 FROM V$ASM_DISK
3 ORDER BY header_status desc, path
4 ;
GROUP# DISK# HEADER_ MODE_ STATE LIBRARY OS_MB TOTAL_MB FREE_MB LABEL PATH
------ ----- ---------- ---------- ------------ ---------------------------- ---------- ---------- ---------- --------------- ----------------------------------------
0 1 MEMBER ONLINE NORMAL System 153584 0 0 /dev/mapper/acfs_01p1
SQL> select name from v$asm_diskgroup order by 1;
NAME
------------------------------------------------------------------------------------------
ACFS_DATA
SQL> alter diskgroup ACFS_DATA mount;
Diskgroup altered.
SQL> SELECT group_number group#, disk_number disk#, header_status header_, mode_status mode_, state, library, os_mb, total_mb, free_mb, label, path
2 FROM V$ASM_DISK
3 ORDER BY header_status desc, path
4 ;
GROUP# DISK# HEADER_ MODE_ STATE LIBRARY OS_MB TOTAL_MB FREE_MB LABEL PATH
------ ----- ---------- ---------- ------------ ---------------------------- ---------- ---------- ---------- --------------- ----------------------------------------
5 0 MEMBER ONLINE NORMAL System 153584 153584 153500 /dev/mapper/acfs_01p1
SQL> select name from v$asm_diskgroup order by 1;
NAME
------------------------------------------------------------------------------------------
ACFS_DATA
SQL>
no rows selected
SQL>
Verify results using asmcmd.
$ asmcmd lsdg -g ACFS_DATA
Inst_ID State Type Rebal Sector Block AU Total_MB Free_MB Req_mir_free_MB Usable_file_MB Offline_disks Voting_files Name
1 MOUNTED EXTERN N 512 4096 4194304 153584 153500 0 153500 0 N ACFS_DATA/
$ asmcmd lsattr -l -G ACFS_DATA
Name Value
access_control.enabled FALSE
access_control.umask 066
au_size 4194304
cell.smart_scan_capable FALSE
compatible.advm 12.1.0.0.0
compatible.asm 12.1.0.0.0
compatible.rdbms 12.1.0.0.0
content.check FALSE
content.type data
disk_repair_time 3.6h
failgroup_repair_time 24.0h
idp.boundary auto
idp.type dynamic
phys_meta_replicated true
sector_size 512
thin_provisioned FALSE
$
Hopefully the information and demonstration will be useful should you encounter the same issues. Reference: ASM Corruption: Case #1: How To Fix The ASM Disk HEADER_STATUS From FORMER or PROVISIONED To MEMBER. (Doc ID 1448799.1)
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