From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dave Eckhardt <davide+p9@cs.cmu.edu>
To: 9fans@9fans.net
In-Reply-To: <714cd9d62658c91ea12dd049c08f7c1f@quanstro.net>
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Content-ID: <10593.1231539507.1@lunacy.ugrad.cs.cmu.edu>
Date: Fri,  9 Jan 2009 17:18:27 -0500
Message-ID: <10594.1231539507@lunacy.ugrad.cs.cmu.edu>
Subject: Re: [9fans] venti
Topicbox-Message-UUID: 7f233fdc-ead4-11e9-9d60-3106f5b1d025

>> Post an (ignored) mode 000 fd in /srv?  Since nobody could open
>> it, it would always have one reference, and would go away when
>> the venti did?

> dns tries a similar trick.

I think /srv/dns serves an actual file system, so there are
potentially many references to it (not just one).

> it also assumes direct-attach storage.

Not exactly, but you are right that ventis running on two
kernels could mount the same storage.

I seem to recall being surprised at some point to observe
/dev/sdXX/data silently imposing a one-open-at-a-time policy
(I think subsequent opens stalled).  Maybe a script run at
system boot time could turn on DMEXCL for appropriate things
in /dev/sd*/*?

Dave Eckhardt