The ASM LMHB trace file is huge in 18.104.22.168 GI environment.
$cd /u01/app/grid/diag/asm/+asm/+ASM1/trace $ ls -ltr *lmhb* -rw-r----- 1 grid oinstall 11551946219 Jan 8 16:59 +ASM1_lmhb_88049.trc
According to (Doc ID 2137683.1), it is a known bug, which is fixed in 12cR2 GI.
Apply one-off Patch 20878790.
Just empty the trace file periodically by :
$ cat /dev/null>+ASM1_lmhb_88049.trc