DBCA does not list ASM diskgroup for storage option

Oracle 19c DBCA does not list ASM disk groups in "Select Database Storage Option" window.

Messages in dbca trace file $ORACLE_BASE/cfgtoollogs/dbca/trace.log_<TIMESTAMP>

[DBStorageOption.flowWorker] [ 2021-03-08 13:24:45.969 EST ] [KfodUtil.kfodOutput:375]  /u01/app/19.0.0/grid/bin/kfod
[DBStorageOption.flowWorker] [ 2021-03-08 13:24:45.969 EST ] [KfodUtil.kfodOutput:375]  nohdr=TRUE
[DBStorageOption.flowWorker] [ 2021-03-08 13:24:45.969 EST ] [KfodUtil.kfodOutput:375]  OP=GROUPS
[DBStorageOption.flowWorker] [ 2021-03-08 13:24:45.969 EST ] [KfodUtil.kfodOutput:375]  status=true
[DBStorageOption.flowWorker] [ 2021-03-08 13:24:45.969 EST ] [KfodUtil.kfodOutput:375]  asmcompatibility=true dbcompatibility=true
[DBStorageOption.flowWorker] [ 2021-03-08 13:24:46.045 EST ] [KfodUtil.kfodOutput:386]  Kfod result
Error 49802 initializing ADR
ERROR!!! could not initialize the diag context
[DBStorageOption.flowWorker] [ 2021-03-08 13:24:46.046 EST ] [ASMUtils.loadDiskGroups:1221]  Loading  the diskgroups. exception using kfodError retrieving diskgroup using kfod utility, null
INFO: Mar 08, 2021 1:24:46 PM oracle.assistants.common.lib.FileSystemInfo getSharedStoragePaths
INFO: Getting default shared storage path.

DBCA failed with command "/u01/app/19.0.0/grid/bin/kfod", manually run the command

[oracle@host01]$ /u01/app/19.0.0/grid/bin/kfod nohdr=TRUE OP=GROUPS status=true asmcompatibility=true dbcompatibility=true
Error 49802 initializing ADR
ERROR!!! could not initialize the diag context

Debug the command with truss or strace as following

  On Linux:  strace -o /tmp/kfod.out /u01/app/19.9.0/grid/bin/kfod nohdr=TRUE OP=GROUPS status=true asmcompatibility=true dbcompatibility=true
  On Solaris/AIX: truss -o /tmp/kfod.out /u01/app/19.0.0/grid/bin/kfod nohdr=TRUE OP=GROUPS status=true asmcompatibility=true dbcompatibility=true

Example on Solaris

[oracle@host01]$ truss -o /tmp/kfod.out /u01/app/19.0.0/grid/bin/kfod nohdr=TRUE OP=GROUPS status=true asmcompatibility=true dbcompatibility=true
Error 49802 initializing ADR
ERROR!!! could not initialize the diag context
[oracle@host01]$
[oracle@host01]$ tail /tmp/kfod.out
stat("/u01/app/19.0.0/grid/log/diag/kfod/host01/kfod/log", 0xFFFFFFFF7FFFBF80) Err#2 ENOENT
stat("/u01/app/19.0.0/grid/log/diag/kfod/host01/kfod", 0xFFFFFFFF7FFFBF80) Err#2 ENOENT
stat("/u01/app/19.0.0/grid/log/diag/kfod/host01", 0xFFFFFFFF7FFFBF80) Err#2 ENOENT
stat("/u01/app/19.0.0/grid/log/diag/kfod", 0xFFFFFFFF7FFFBF80) Err#2 ENOENT
stat("/u01/app/19.0.0/grid/log/diag", 0xFFFFFFFF7FFFBF80) = 0
getuid()     = 104 [104]
getgid()     = 112 [112]
getuid()     = 104 [104]
getuid()     = 104 [104]
mmap(0x00010000, 65536, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANON|MAP_ALIGN, -1, 0) = 0xFFFFFFFF73900000
getuid()     = 104 [104]
getuid()     = 104 [104]
open("/system/volatile/name_service_door", O_RDONLY) = 6
fcntl(6, F_SETFD, 0x00000001)   = 0
door_info(6, 0xFFFFFFFF75D8B5B0)  = 0
door_call(6, 0xFFFFFFFF7FFFBBB8)  = 0
ioctl(1, TCGETA, 0xFFFFFFFF7FFF8F7C)  = 0
fstat(1, 0xFFFFFFFF7FFF8F10)   = 0
write(1, " E r r o r   4 9 8 0 2  ".., 29) = 29
write(1, " E R R O R ! ! !   c o u".., 47) = 47
close(5)     = 0
_exit(1)

From the trace file /tmp/kfod.out, kfod failed with accessing following directories

    /u01/app/19.0.0/grid/log/diag/kfod/host01/kfod/log
    /u01/app/19.0.0/grid/log/diag/kfod/host01/kfod
    /u01/app/19.0.0/grid/log/diag/kfod/host01
    /u01/app/19.0.0/grid/log/diag/kfod
    /u01/app/19.0.0/grid/log/diag

Check the permission of the directory

[oracle@host01]$ ls -ld /u01/app/19.0.0/grid/log/diag
drwxr-x---   4 grid     oinstall       5 Dec 12 23:17 /u01/app/19.0.0/grid/log/diag
[oracle@host01]$ id
uid=104(oracle) gid=112(oinstall)

oracle, who is running kfod, is member of group oinstall, but group oinstall does not have write permission on directory. Trying to grant write permission as root or grid (owner of GI home)

[grid@host01]$ chmod g+w /u01/app/19.0.0/grid/log/diag
[grid@host01]$ ls -ld /u01/app/19.0.0/grid/log/diag
drwxrwx---   4 grid     oinstall       5 Dec 13 02:45 /u01/app/19.0.0/grid/log/diag

Re-try kfod as oracle

[oracle@host01]$ /u01/app/19.0.0/grid/bin/kfod nohdr=TRUE OP=GROUPS status=true asmcompatibility=true dbcompatibility=true
    204528     188110 EXTERN REDO 10.1.0.0.0 12.1.0.0.0
    613584     388124 EXTERN FRA  10.1.0.0.0 12.1.0.0.0
   4091624     470712 EXTERN DATA 10.1.0.0.0 12.1.0.0.0

Now, dbca can list ASM disk groups.