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From: erik quanstrom <quanstro@labs.coraid.com>
To: 9fans@9fans.net
Subject: Re: [9fans] Help with two small shared file servers
Date: Thu, 18 Aug 2011 01:29:29 -0400	[thread overview]
Message-ID: <afa907c3be69717b86a41caafe955006@coraid.com> (raw)
In-Reply-To: <20110817210038.66E0CB827@mail.bitblocks.com>

> > Is 9p suitable for this? How will the 40ms latency affect 9p
> > operation? (I have 100Mbit).
>
> With a strict request/response protocol you will get no more
> than 64KB once every 80ms so your throughput at best will be
> 6.55Mbps or about 15 times slower than using HTTP/FTP on
> 100Mbps link for large files.  [John, what was the link speed
> for the tests in your thesis?]

i calculate 1/0.080s/rt * 64*1024 = 819 kbytes/s.  (i think your
conversion from mbits/s to bytes/s is faulty.)

also you do get 1 oustanding per read or write, not per machine.
so the real limit is wire speed, but for most programs most of the
time the limit for a single file transfer would be as you specify.

- erik



  parent reply	other threads:[~2011-08-18  5:29 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-08-17 10:09 Aram Hăvărneanu
2011-08-17 14:11 ` Anthony Sorace
2011-08-17 14:32   ` John Floren
2011-08-17 15:39   ` erik quanstrom
     [not found]   ` <CAL4LZyiEk35Kfq_wezUaEvJWsYX3ONeordrD7sQjFr+45fQiWg@mail.gmail.c>
2011-08-18  5:34     ` erik quanstrom
2011-08-18  5:48       ` John Floren
     [not found]       ` <CAL4LZygoKQZoTvof4F_fBQhxqsQZb2r+FR_nkgf=YbU94WvoBQ@mail.gmail.c>
2011-08-18 13:26         ` erik quanstrom
2011-08-18 14:21           ` Lucio De Re
2011-08-19  8:15           ` cinap_lenrek
2011-08-17 21:00 ` Bakul Shah
2011-08-17 21:19   ` John Floren
2011-08-17 21:22   ` Skip Tavakkolian
2011-08-18  5:29   ` erik quanstrom [this message]
2011-08-18  5:47     ` Tristan Plumb
2011-08-18  6:25     ` Bakul Shah
2011-08-30 21:40 ` Ethan Grammatikidis
     [not found] <CAEAzY3_Vx8WW1Oumt0t1_Ay6LtpTFFonpwMD+=0DYCM-yxXaeA@mail.gmail.c>
2011-08-17 15:42 ` erik quanstrom

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