Re: somewhat OT query on journalling

[Hans Reiser <reiser@namesys.com>]

Payal Rathod wrote:

>Hi,
>I was just reading about filesystems and my ideas are a bit confused.
>I read quite a few articles on net but still my basic doubts are not 
>completely clarified. I thought this would be the right place to ask, since many 
>journalling gurus might be here.
>Can someone tell me do journalling fs maintain journal about the 
>metadata or the all the data?
>  
>
V3 defaults to metadata only, V4 does data also because we can do it
without performance loss.

>Also, is it true that now-a-days there is no such thing as inode "block"
>since  for faster access the inodes are kept near the data itself?
>  
>
reiserfs does not use inodes at all.  see our website for more.

>How is the journal maintained? How is it prevented from being
>too big and why are these fs not slower than traditional fs since it 
>involves an overhead of writing to a journal?
>  
>
see website.  there is overhead.  for v4 it is not a lot though.

>And lastly don't the journalling fs give a false sense of security to 
>the user, saying that the data is written to disk when in reality only an 
>entry is made in journal and data is still not committed to disk.
>  
>
someone else anwered this....

>Thanks a lot for the patience and eagerly waiting for any replies.
>
>With warm regards,
>-Payal
>
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