How to use external journal?

How to use external journal?

[Luis Gregorio Muniz Rodriguez]

Hi there!

I have recently discovered that the journal can be placed on an external
device (i.e, `mkreiserfs --journal-device <FILE>'), but I haven't found
any doc about it.

I'm currently using ReiserFS on top of LVM partitions, and I am
wondering if I can use the same shared journal device for a number of
small partitions.  

Note that I'm not trying to move all the journals to the same device
(this should be easy using `--journal-device' and `--journal-offset',
isn't it?).  Rather, I try to share the same 32Mb journal between small
filesystems and/or filesystems with infrequent writes (such as </usr>,
</usr/local>, </var/www>, and so on).


Is that possible?  And convenient?
Many thanks in advance,
--
	- Luis Mu~niz 	<kreator@lmunix.net>

Re: How to use external journal?

[Oleg Drokin]

Hello!

On Mon, Dec 23, 2002 at 04:57:04PM +0100, Luis Gregorio Muniz Rodriguez wrote:
> I have recently discovered that the journal can be placed on an external
> device (i.e, `mkreiserfs --journal-device <FILE>'), but I haven't found
> any doc about it.

If you do not use 2.5 kernels, you need to apply separate patch to your tree.

> I'm currently using ReiserFS on top of LVM partitions, and I am
> wondering if I can use the same shared journal device for a number of
> small partitions.  

No, you cannot.

> Note that I'm not trying to move all the journals to the same device
> (this should be easy using `--journal-device' and `--journal-offset',
> isn't it?).  Rather, I try to share the same 32Mb journal between small
> filesystems and/or filesystems with infrequent writes (such as </usr>,
> </usr/local>, </var/www>, and so on).
> Is that possible?  And convenient?

This is not possible.
But you can divide these "shared" 32M into four separate parts 
and use these with --journal-offset.

Bye,
    Oleg