From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Fedyk <mfedyk@matchmail.com>
Subject: Re: reiserfs logging patches udpated
Date: Mon, 29 Mar 2004 10:49:06 -0800
Message-ID: <40686FA2.1010501@matchmail.com>
References: <1080149399.14737.77.camel@watt.suse.com>	 <20040324143516.3162cbfe.akpm@osdl.org>	 <1080168379.14743.124.camel@watt.suse.com>	 <200403250147.54246.bernd-schubert@web.de> <40625867.4060800@matchmail.com>	 <1080224062.26677.3.camel@watt.suse.com> <406343F1.2050504@matchmail.com> <1080247847.2926.0.camel@watt.suse.com> <4068203E.4050700@namesys.com>
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To: Hans Reiser <reiser@namesys.com>
Cc: Chris Mason <mason@suse.com>, Bernd Schubert <bernd-schubert@web.de>, reiserfs-list@namesys.com, Andrew Morton <akpm@osdl.org>

Hans Reiser wrote:
> Chris Mason wrote:
> 
>> On Thu, 2004-03-25 at 15:41, Mike Fedyk wrote:
>>  
>>
>>> Chris Mason wrote:
>>>   
>>>
>>>> On Wed, 2004-03-24 at 22:56, Mike Fedyk wrote:
>>>>
>>>>
>>>>     
>>>>
>>>>> And after having the difference of a block level journal (ext3), 
>>>>> instead of a "virtual" journal(reiserfs, jfs, xfs) explained to me 
>>>>> (check the ext3-users archives...) -- and how it can save your ass 
>>>>> when there are hardware problems.  I was convinced and switched 
>>>>> everything back to ext3.
>>>>>       
>>>>
>>>> reiserfs does block based logging ;-)
>>>>     
>>>
>>> I stand corrected.
>>>
>>> Thanks Chris, I feel much better about reiserfs now, especially with 
>>> your ordered/data journaling patches.
>>>   
>>
>>
>> One other point, the current patch set only does data=ordered.  I wanted
>> that fully stabilized before I enabled data=journal.
>>
>> -chris
>>
>>
>>
>>
>>  
>>
> what is a virtual journal?
> 

The basic idea of virtual vs block journals, is that instead of using a 
few bytes to describe what you're changing in (for instance) the inode 
table (or equivalent), ext3 (and reiser3 thanks to info from Chris 
Mason) copies entire inode table block (usually 1-4k depending on block 
size) into the journal.