On Mon, 2006-08-14 at 09:13 +0400, Evgeniy Polyakov wrote:

On Sun, Aug 13, 2006 at 01:16:15PM -0700, Daniel Phillips (phillips@google.com) wrote:

quoted

Indeed.  The rest of the corner cases like netfilter, layered protocol and
so on need to be handled, however they do not need to be handled right now
in order to make remote storage on a lan work properly.  The sane thing for
the immediate future is to flag each socket as safe for remote block IO or
not, then gradually widen the scope of what is safe.  We need to set up an
opt in strategy for network block IO that views such network subsystems as
ipfilter as not safe by default, until somebody puts in the work to make
them safe.

Just for clarification - it will be completely impossible to login using 
openssh or some other priveledge separation protocol to the machine due
to the nature of unix sockets. So you will be unable to manage your
storage system just because it is in OOM - it is not what is expected
from reliable system.

quoted

But really, if you expect to run reliable block IO to Zanzibar over an ssh
tunnel through a firewall, then you might also consider taking up bungie
jumping with the cord tied to your neck.

Just pure openssh for control connection (admin should be able to
login).

These periods of degenerated functionality should be short and
infrequent albeit critical for machine recovery. Would you rather have a
slower ssh login (the machine will recover) or drive/fly to Zanzibar to
physically reboot the machine?