e2fsck.conf and ssh_known_hosts: where?

[Paul E Condon <pecondon@mesanetworks.net>]

e2fsck.conf:

While attempting to debug a flaky HDD under Jessie, I had occasion to
inspect the conf file /etc/e2fsck.conf, and found that it doesn't
exist on any of my computers. But the man e2fsck mentions file
e2fsck.conf and man e2fsck.conf states that the default location is
/etc/e2fsck.conf . Has support for site specific configuration been
abandoned? Or where is it kept?

(open)ssh-known-hosts:

While searching in /var to see if I could find e2fsck.conf without
asking I found an empty directory, /var/cache/openssh-known-hosts .

The Debian wiki has an article about how to use ssh-keyscan to build a
small database of known hosts for use on a LAN. The article says the
file (not directory) of known hosts should placed in /etc/ssh. Is
Debian's plan to move to using /var for a known-hosts DB? or is the
empty directory just some cruft?  I think a directory is a better way
than a file, because it is easier to make atomic changes in directory
structure than adding/removing individual lines in a file. Both /var
and /etc are OK as a location, for me. Does the software that
implements known-host checking at ssh-login-time look in both places?
Does it look for both names (hyphens vs. underscores)?

Kind regards,
-- 
Paul E Condon           
pecondon@mesanetworks.net