"hard mounts"

Lyle Seaman lws@spinnakernet.com
Sat, 17 Mar 2001 10:59:53 -0500

Phil.Moore@msdw.com wrote:

> We depend on this here at MSDW, and without it, wouldn't be running
> AFS.  See the long winded story below if you don't understand why this
> is so important.

I think I can explain this concisely.  MSDW has (had?) an essentially
data-less configuration.  98% of the client OS executables actually
resided in AFS Read-Only volumes, especially including the X server and
some other critical things.

In the event of a network outage, the client would sequentially time-out
on each of the three or four replicas, and then X would crash, along with
all the applications.  Recovery basically involved rebooting,
which turned a four-minute outage into a 15-minute outage.

Worse, if the network outage affected a hundred clients, and then a
hundred clients were forced to reboot more-or-less simultaneously, they
would hit the file servers pretty hard, turning a 15-minute outage into a
half-hour outage.

(how's that?  about right? )