Re: [dm-devel] [RFC] [PATCH] lvm2: mirroredlog support

[Alasdair G Kergon <agk redhat com>]

On Wed, Sep 30, 2009 at 10:50:06AM -0500, Jon Brassow wrote:
> As long as we are on the topic of mirror logs (and this is unrelated to 
> your patch), I'd like to complain about the current behavior of log  
> allocation vs the log policy.  I don't think it should take  
> 'alloc_anywhere' for a log to be placed on the same disk as one of the  
> mirror legs... that should be 'alloc_normal'.

It was assumed that performance would be better this way, but I have
never seen any tests to prove or disprove that.  Maybe someone could run
some?

One way we could handle this is by creating a new policy between
NORMAL and ANYWHERE that does this, then renaming the old NORMAL
to something else and the new policy to NORMAL.

Alasdair