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Date: Tue, 20 Jun 2006 14:32:28 -0600
From: Scott Long <scottl@samsco.org>
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To: Mike Jakubik <mikej@rogers.com>
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Cc: freebsd-fs@freebsd.org, Pawel Jakub Dawidek <pjd@freebsd.org>,
	freebsd-current@freebsd.org, Xin LI <delphij@delphij.net>,
	freebsd-geom@freebsd.org
Subject: Re: Journaling UFS with gjournal.
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Mike Jakubik wrote:
> Xin LI wrote:
> 
>> 在 2006-06-20二的 21:36 +0200，Pawel Jakub Dawidek写道：
>>  
>>
>>> The performance impact is big for large files, because in theory we have
>>> to write the data twice.
>>> Yes, it eliminates need for SU, but there are reasons, that you still
>>> want to use SU, eg. for snapshots.
>>>     
>>
>>
>> Em...  IIRC SU and snapshots are independent, no?
>>
>> Cheers,
>>   
> 
> 
> What about mounting the filesystem async though? It was my understanding 
> that the Linux filesystems were much faster in benchmarks because they 
> were mounted async by default, however the presence of journaling 
> allowed this safely. Is this the case here too?
> 

Yes, async mounting is much faster that sync mounting, and slightly 
faster than SU, except when SU is dealing with huge data sets.  Then
async is significantly faster.

Scott