From: Francisco Ballesteros <nemo@lsub.org>
To: Fans of the OS Plan 9 from Bell Labs <9fans@cse.psu.edu>
Subject: [9fans] reliability and failing over.
Date: Sat, 10 Sep 2005 00:10:58 +0200 [thread overview]
Message-ID: <600308d6050909151067389b35@mail.gmail.com> (raw)
In-Reply-To: <20050909210534.GI4207@server4.lensbuddy.com>
Funny. The 9p reliability project looks to me a lot like the redirfs
that we played with before introducing the Plan B volumes into the kernel.
It provided failover (on replicated FSs, by some other means) and could
recover the fids just by keeping track of their paths.
The user level process I'm with now is quite similar to that (appart from
including the language to select particular volumes) it maintains a fid
table knowning which server, and which path within the server are the ones
for each fid. It's what the Plan B kernel ns does, but within a server.
Probably, the increase in latency you are seeing is the one I'm going to
see in volfs. The 2x penalty in performace is what one could expect, because
you have twice the latency. However, the in-kernel implementation has no
penalty at all, because the kernel can rewrite the mount tables.
Maybe we should talk about this.
Eric? Russ? What do you say? Is it worth to pay the extra
latency just to avoid a change (serious, I admit) in the kernel?
On 9/9/05, Uriel <uriell@binarydream.org> wrote:
> On Fri, Sep 09, 2005 at 10:55:01PM +0200, Francisco Ballesteros wrote:
> > What about sched´ing the next town hall meeting
> > for the third friday of september?
> > I'm willing to run it if there are no objections or anyone else
> > prefers to do that.
> >
> > Preferences regarding time? Was the last one (8pm gmt?)
> > convenient?
> I had tentatively scheduled the next THM for Sep 10th, but I have been
> too stressed to even send out an announcement.
>
> After some research it seems that Saturdays are the best days for most
> people(specially given the diversity of timezones involved), 20:00 GMT
> seems like a time that works reasonably well for most people.
>
> For consistency(and avoid having to come up with a new date/time), I
> suggest having a THM the third Saturday of the month at 20:00 GMT
>
> Any complains? if not, I will make it 'official' in the Wiki
>
> For the Summary of the last THM see(thanks to Hyperion for writing it
> up):
>
> http://plan9.bell-labs.com/wiki/plan9/thm_2005-08-15_Summary/
>
> uriel
>
next prev parent reply other threads:[~2005-09-09 22:10 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-09-09 20:55 [9fans] sept. town hall meeting Francisco Ballesteros
2005-09-09 21:05 ` Uriel
2005-09-09 22:10 ` Francisco Ballesteros [this message]
2005-09-09 22:24 ` [9fans] reliability and failing over Russ Cox
2005-09-09 22:50 ` Gorka guardiola
2005-09-09 23:02 ` Francisco Ballesteros
2005-09-09 23:06 ` Russ Cox
2005-09-09 23:16 ` Francisco Ballesteros
2005-09-10 13:11 ` Sape Mullender
2005-09-10 21:36 ` Francisco Ballesteros
2005-09-10 1:22 ` Eric Van Hensbergen
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