From: Avi Kivity <avi@redhat.com>
To: jim owens <jowens@hp.com>
Cc: Tejun Heo <tj@kernel.org>, linux-btrfs@vger.kernel.org
Subject: Re: Some very basic questions
Date: Wed, 22 Oct 2008 21:22:08 +0200 [thread overview]
Message-ID: <48FF7D60.70600@redhat.com> (raw)
In-Reply-To: <48FF7B4D.80004@hp.com>
jim owens wrote:
>>> For most SATA drives, disabling write back cache seems to take high
>>> toll on write throughput. :-(
>>
>> I measured this yesterday. This is true for pure write workloads;
>> for mixed read/write workloads the throughput decrease is negligible.
>
> Different tests on different hardware
> give different results at different times!
>
True. But data loss is forever!
>>
>> I got flamed for this on another list, but let's disable the write
>> cache and live with the performance drop.
>
> We don't get to decide this, customers do.
We get to pick the defaults.
> As they say in the raid forum... fast, cheap, good - pick any 2
We can upgrade slow to fast, but !good gets upgraded to another fs.
> P.S. no flames because we chose no-battery == disable-write-cache
ACK!
--
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.
next prev parent reply other threads:[~2008-10-22 19:22 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-10-21 11:23 Some very basic questions 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 [this message]
2008-10-22 19:59 ` Ric Wheeler
2008-10-22 21:31 ` Eric Anopolsky
2008-10-22 21:56 ` Ric Wheeler
-- strict thread matches above, loose matches on Subject: below --
2008-10-21 17:37 calin
2008-10-21 20:08 ` jim owens
2008-10-22 7:15 ` Avi Kivity
2008-10-22 14:13 ` jim owens
2008-10-22 14:25 ` Avi Kivity
2008-10-22 14:35 dbz
2008-10-27 15:43 ` Stephan von Krawczynski
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