[linux-lvm] Book chapter

[linux-lvm] Book chapter

[Moshe Bar]

Hi Heinz

I am writing a chapter about LVM in my book. I would like to
know more about the internal data structures and the
algorithms used. 

Can you tell me more about them (next to what is in the
source code) or point me to some document about the
internals of LVM (interaction with VFS, etc.).

Many thanks

moshe bar

Re: [linux-lvm] Book chapter

[Rik van Riel]

On Thu, 5 Jul 2001, Moshe Bar wrote:

> I am writing a chapter about LVM in my book. I would like to
> know more about the internal data structures and the
> algorithms used.
>
> Can you tell me more about them (next to what is in the
> source code) or point me to some document about the
> internals of LVM (interaction with VFS, etc.).

It's a block device layer thing, so it doesn't interact
with the VFS. What the LVM layer _seems_ to do is simply
remap an IO request to the device it's supposed to go to
and let the request get into the IO layer again...

(then again, I could be wrong here, the LVM code isn't
the easiest to wade through)

Rik
--
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Re: [linux-lvm] Book chapter

[Joe Thornber]

On Fri, Jul 06, 2001 at 05:23:54PM -0300, Rik van Riel wrote:
> On Thu, 5 Jul 2001, Moshe Bar wrote:
> 
> > I am writing a chapter about LVM in my book. I would like to
> > know more about the internal data structures and the
> > algorithms used.
> >
> > Can you tell me more about them (next to what is in the
> > source code) or point me to some document about the
> > internals of LVM (interaction with VFS, etc.).
> 
> It's a block device layer thing, so it doesn't interact
> with the VFS. What the LVM layer _seems_ to do is simply
> remap an IO request to the device it's supposed to go to
> and let the request get into the IO layer again...

Rik's correct, LVM has nothing to do with the VFS.  If you wish to explore
the code start with lvm_map() which maps a buffer destined for a logical 
volume onto a physical device.
 
> (then again, I could be wrong here, the LVM code isn't
> the easiest to wade through)

Agreed.

- Joe