About flags

pause :if set, no IO requests will be sent to any OSD

noup : prevent OSDs from getting marked up
nodown : prevent OSDs from getting marked down
noout : prevent OSDs from getting marked out
noin :prevent OSDs from getting marked in

noin and noout prevent booting OSDs from being marked in (allocated data) or protect OSDs from eventually being marked out (regardless of what the current value for mon osd down out interval is).
noup, noout, and nodown are temporary in the sense that once the flags are cleared, the action they were blocking should occur shortly after.
The noin flag, on the other hand, prevents OSDs from being marked in on boot, and any daemons that started while the flag was set will remain that way.

nobackfill
norecover

noscrub
nodeep-scrub

notieragent : This will pause tiering agent work