The following is a demonstration of the vmbypid.d command,
# vmbypid.d
Tracing... Hit Ctrl-C to end.
^C
EXEC PID VM VALUE
find 19216 prot_fault 1
bash 19216 zfod 1
dtrace 19215 pgfrec 3
dtrace 19215 pgrec 3
bash 19216 pgfrec 5
bash 19216 pgrec 5
find 19216 cow_fault 6
find 19216 pgfrec 6
find 19216 pgrec 6
bash 19216 prot_fault 10
bash 19216 cow_fault 15
bash 19155 prot_fault 30
dtrace 19215 zfod 52
find 19216 zfod 54
dtrace 19215 as_fault 56
bash 19216 as_fault 74
find 19216 as_fault 91
find 19216 fspgin 315
find 19216 pgin 315
find 19216 pgpgin 315
find 19216 maj_fault 315
In the above output, the find command at PID 19211 triggered 315 maj_faults -
major faults, that would require disk activity to satisfy (as confirmed by the
pgpgin value for pages paged in).