SATA mirrror performance

[Ashley Moran]

On Sep 18, 2007, at 10:21 pm, Joao Carlos Mendes Luis wrote:

> The main advantage of ataraid is its integration with BIOS and  
> other operating systems.  If we had something like a master GEOM  
> device which could read ata raid specs and build GEOM graphs based  
> on this information, that would be a good workaround.  I am not  
> sure if this is enough, but at least would solve startup problems.   
> I am also not sure if it is even possible, because no single GEOM  
> device would suffice: The master device should recognize disk  
> labels, and call geom_mirror, geom_strip, geom_raid5, etc when  
> needed.  I hope GEOM architects have something in mind, because  
> this is very important to desktop and dual boot.

I can see your point, although I don't understand geom enough to  
comment on everything you say.  I just wonder though, are there many  
users that need to dual-boot a mirror?  I have only used gmirror on  
servers, but then I am Mac user on the desktop, so any other OS's I  
need I will virtualise.


> I can deal with geom_mirror, but I am not a typical user.  Most  
> users don't even know FreeBSD supports mirroring, since it is not  
> on installation options menu.  Indeed, install a FreeBSD with boot  
> mirror support was still a complex task the last time I saw  
> sysinstall.

It's not that hard, you just escape to the shell on the initial  
sysinstall, and add the second provider after you reboot.  It's  
definitely beyond a "typical user", but then like I say, I don't know  
any "typical users" who want RAID-1.  I do agree though, that a way  
to configure this in sysinstall would be very nice.

Ashley