fa=(/mnt/o/btrbk/o.*); f=${fa[0]}
if [[ -e $f ]]; then
if [[ $o_dev != "$root_dev" ]]; then
+ # ,compress=zstd regardless of mopts since these are all text files
+ # and it cuts disk use by about half.
fstab <<EOF
-$o_dev /o btrfs noatime,subvol=o$mopts 0 0
+$o_dev /o btrfs noatime,subvol=o${mopts/,compress=zstd/},compress=zstd 0 0
EOF
fi
fstab <<EOF