[Dovecot] linux 2.4 vs 2.6 kernel

[Marc Perkel]

vmstech wrote:

>>>  
>>>      
>>>
>>Wow - that's interesting. I didn't know there was a btree option for
>>Ext3. I thought only Reiser had that. I
>>    
>>
>is btree and htree the same thing? Sorry - way out of my depth here.
>
>  
>
I doubt they are exactly the same but the concept is that a tree 
required to get speed is what they have in common. If you don't have a 
tree then you have to do a linear search. If you have 100,000 files in a 
directory it will take an average of 50,000 comparisons for every file 
you open. That can get really slow. In a tree system you'll probably 
have under 10 comparisons. That's why people prefer Reiser for Maildir 
where you have lots of files in one directory.

If you had a few big files and wanted speed then Ext3 is faster. If you 
have lots of little files in a single directory you want reiser.

-- 
Marc Perkel - marc at perkel.com

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    My Blog: http://marc.perkel.com

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