Re: Superblock V 1.2

[Neil Brown <neilb@suse.de>]

On Mon, 15 Nov 2010 14:52:20 -0500
Martin Cracauer <cracauer@cons.org> wrote:

> Neil Brown wrote on Tue, Nov 16, 2010 at 06:47:46AM +1100: 
> > On Mon, 15 Nov 2010 11:16:46 -0500
> > Martin Cracauer <cracauer@cons.org> wrote:
> > 
> > > Neil Brown wrote on Mon, Nov 15, 2010 at 12:11:58PM +1100: 
> > > > 
> > > > When mdadm does auto-assemble an array that doesn't obviously belong to this
> > > > host, it tries to be careful and assembles it 'read-auto', which means that
> > > > it is completely read-only until you try to write to the array.  So no
> > > > recovery or resync happens.
> > > > Once you write to the array, md assumes that you are happy to have the array
> > > > assembled on this device, and allows any resync etc to start.
> > > 
> > > Speaking of which, are there any plans to do a true readonly mode?
> > > 
> > > I missed that quite a few times.
> > > 
> > > Martin
> > 
> > In what does
> >    mdadm --readonly /dev/mdXX
> > 
> > not meet your needs?
> > (which is to say:  I think there is a true readonly mode, but I've never
> > seriously used it so don't know for certain that it is actually useful).
> 
> Isn't that the mode that upgrades to read-write when you write?
> 

No.

NeilBrown