Linux Btrfs filesystem development
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From: Avi Kivity <avi@redhat.com>
To: jim owens <jowens@hp.com>
Cc: Stephan von Krawczynski <skraw@ithnet.com>, linux-btrfs@vger.kernel.org
Subject: Re: Some very basic questions
Date: Wed, 22 Oct 2008 09:15:05 +0200	[thread overview]
Message-ID: <48FED2F9.1060103@redhat.com> (raw)
In-Reply-To: <48FE36BD.6020701@hp.com>

jim owens wrote:
>
> Remember that the device bandwidth is the limiter so even
> when each host has a dedicated path to the device (as in
> dual port SAS or FC), that 2nd host cuts the throughput by
> more than 1/2 with uncoordinated seeks and transfers.

That's only a problem if there is a single shared device.  Since btrfs 
supports multiple devices, each host could own a device set and access 
from other hosts would be through the owner.  You would need RDMA to get 
reasonable performance and some kind of dual-porting to get high 
availability.  Each host could control the allocation tree for its devices.

Of course, this doesn't solve the other problems with parallel mounts.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.


  reply	other threads:[~2008-10-22  7:15 UTC|newest]

Thread overview: 79+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-21 17:37 Some very basic questions calin
2008-10-21 20:08 ` jim owens
2008-10-22  7:15   ` Avi Kivity [this message]
2008-10-22 14:13     ` jim owens
2008-10-22 14:25       ` Avi Kivity
  -- strict thread matches above, loose matches on Subject: below --
2008-10-22 14:35 dbz
2008-10-27 15:43 ` Stephan von Krawczynski
2008-10-21 11:23 Stephan von Krawczynski
2008-10-21 12:13 ` Andi Kleen
2008-10-21 14:22   ` Stephan von Krawczynski
2008-10-21 15:34     ` jim owens
2008-10-22 11:36       ` Stephan von Krawczynski
2008-10-22 12:15         ` Avi Kivity
2008-10-22 13:03           ` Ric Wheeler
2008-10-22 13:13             ` Chris Mason
2008-10-22 13:16             ` Avi Kivity
2008-10-21 13:20 ` jim owens
2008-10-21 17:01   ` Stephan von Krawczynski
2008-10-21 17:15     ` Christoph Hellwig
2008-10-21 17:31       ` Ric Wheeler
2008-10-22 12:27         ` Stephan von Krawczynski
2008-10-22 13:15           ` Chris Mason
2008-10-22 13:27             ` Ric Wheeler
2008-10-22 14:32               ` Avi Kivity
2008-10-22 14:36                 ` Chris Mason
2008-10-22 14:40                   ` Avi Kivity
2008-10-22 14:46                 ` Ric Wheeler
2008-10-22 14:54                   ` Avi Kivity
2008-10-22 15:02                     ` Ric Wheeler
2008-10-22 15:13                       ` Avi Kivity
2008-10-22 15:25                         ` Ric Wheeler
2008-10-22 15:33                           ` Chris Mason
2008-10-22 15:43                             ` Avi Kivity
2008-10-22 15:54                               ` Ric Wheeler
2008-10-22 18:28                                 ` Avi Kivity
2008-10-22 15:39                           ` Avi Kivity
2008-10-22 13:52             ` Stephan von Krawczynski
2008-10-22 15:56               ` Michel Salim
2008-10-22 16:56                 ` jim owens
2008-10-23  9:47                 ` Stephan von Krawczynski
2008-10-22 11:40       ` Stephan von Krawczynski
2008-10-21 13:59 ` Chris Mason
2008-10-21 16:09   ` Andi Kleen
2008-10-22 11:43     ` Stephan von Krawczynski
2008-10-21 16:27   ` Stephan von Krawczynski
2008-10-21 16:59     ` Andi Kleen
2008-10-22 11:46       ` Stephan von Krawczynski
2008-10-21 17:49     ` Chris Mason
2008-10-22 12:19       ` Stephan von Krawczynski
2008-10-22 12:48         ` Jeff Schroeder
2008-10-22 14:02           ` Stephan von Krawczynski
2008-10-22 13:50         ` Chris Mason
2008-10-22 14:04           ` Matthias Wächter
2008-10-22 14:32             ` Ric Wheeler
2008-10-22 14:44               ` jim owens
2008-10-24  8:42           ` Chris Samuel
2008-10-24  8:39         ` Chris Samuel
2008-10-21 20:54   ` Eric Anopolsky
2008-10-21 22:18     ` Ric Wheeler
2008-10-22  2:29       ` Eric Anopolsky
2008-10-22 10:42         ` Ric Wheeler
2008-10-22 10:53           ` Tejun Heo
2008-10-22 12:57             ` Ric Wheeler
2008-10-22 12:57             ` Ric Wheeler
2008-10-22 13:15               ` Tejun Heo
2008-10-22 13:19                 ` Chris Mason
2008-10-22 13:38                   ` Ric Wheeler
2008-10-22 13:59                     ` Chris Mason
2008-10-22 14:23                       ` Ric Wheeler
2008-10-22 13:23                 ` Ric Wheeler
2008-10-22 16:14                   ` Tejun Heo
2008-10-22 16:34                     ` Ric Wheeler
2008-10-23  3:59                       ` Tejun Heo
2008-10-22 18:32                     ` Avi Kivity
2008-10-22 19:13                       ` jim owens
2008-10-22 19:22                         ` Avi Kivity
2008-10-22 19:59                       ` Ric Wheeler
2008-10-22 21:31                     ` Eric Anopolsky
2008-10-22 21:56                       ` Ric Wheeler

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