Re: Vinum status

On Mon, 2 Aug 2004, Paul Mather wrote:

> I'm happy to report that the current geom_vinum kernel module
> successfully detects all plexes during boot when loaded from
> /boot/loader.conf.  So, I now have a working root-on-gvinum setup
> running (including swap-on-gvinum).  Thanks!!

Now that's very good news!  Thanks for testing it!

> My only question is that although writes go to both disks in my mirrored
> setup, reads are only done from one disk of the mirror.  In my case, all
> reads are always to drive ad2 of my ad0+ad2 mirror.  This implies to me
> a default "readpol prefer <someplex>" on my defined volumes rather than
> the "readpol round" that appears to be the default under vinum.  (At
> least on my 4.10-STABLE system, both drives are used for reads, implying
> a "readpol round" default behaviour.)

Yes, I still need to implement some details.  Round-robin reads is one of 
them.

> Does gvinum support "readpol round" or is it just that its default
> differs from the old vinum?  If the latter, is there a way to change the
> read policy on a volume without deleting the old volume or otherwise
> destroying its contents?  The vinum configuration I'm using is an exact
> duplicate of a 5.1-RELEASE system I created.  That system (since
> upgraded to 5.2.1-RELEASE-p9) also sends reads to both drives using
> vinum.

Yes, I'll make these config changes possible without dumping and 
restoring. :-)

> (Will you link the kernel module into the normal kernel build?  I forgot 
> it wasn't the first time I built my kernel, and had to go back and build 
> manually the geom_vinum module when I couldn't find it to load when at 
> the boot loader prompt.  Ditto for including gvinum in the regular 
> userland build process.)

Yes, it's about time to hook them up. :-)

thanks,
le

-- 
Lukas Ertl                         http://homepage.univie.ac.at/l.ertl/
le_at_FreeBSD.org                     http://people.freebsd.org/~le/