Solution to RAID /boot issue in fc17?

[Alan Cox]

On Tue, 29 May 2012 23:02:14 -0400
Sam Varshavchik <mrsam at courier-mta.com> wrote:

> Alex writes:
> 
> > Hi,
> >
> > I believe the ability to have /boot on RAID was removed in fc15 so in
> > fc16,
> 
> That's news to me. Both F15 and F16 were perfectly happy with /boot on  
> RAID-1, for me. I must admit that they were quite reluctant to do so, and I  
> did have to beat the crap out of both of them; and I lost two good weekends  
> fighting their insolence, before they finally agreed to /boot off RAID-1. 
> But after I showed them who's the boss, there were no complaints.

It's been officially removed repeatedly and works fine, at least on FC16.
It does need to be RAID 1

> There were two issues that made RAID-1 for /boot in F15 and F16 a nightmare.
> 
> If your partition table starts at sector 63, you're most likely boned,  
> because grub2 too fat, with RAID-1 loaded.

Thats complete crap. The Fedora installer is utterly broken here. Grub2
is just fine. If you do the install by hand it all works fine.

> Also, on some RAID-based system, anaconda kept generating a grub.conf that  
> was a complete work of fiction. That, of course, didn't help things either.  
> Fortunately, you can still boot in rescue mode, and run grub2-mkconfig to  
> regenerate a grub.conf that has some basis in reality.

Count yourself lucky - if it can only find part of an old RAID volume eg
a stale header the FC16 installer just crashed. FC17 has introduced a new
bug where you can't install onto a degraded RAID1 array, which prevents
all sorts of useful stuff working.

> Now, if your partition table starts at sector 63, you're still boned. But  

Nope. You can do it by hand.

> not quite. If you're running RAID-1, it is possible, with the help of a  
> rescue disk, and with stable UPS providing insurance, nurse the server into  
> restitching all the partitions so that they now start on sector 2048, one  
> disk at a time, without having to back them up, and redo.
> 
> Bugzilla tells me that F17's anaconda has a better reputation in emitting  
> grub.conf for RAID-based system, so that's fixed. But, if your partitions  
> still start on sector 63, you're still boned. You must move them.

Nope. You can do it by hand. It's just Fedora installer breakage and the
rest is a myth of unknown origin.

Basically the Fedora installer is a mess. It's been going downhill for
years and it just gets worse each release. Unfortunately with FC17 you
can't really avoid using it due to the giant re-arrangement of /bin
and /usr/bin.

It doesn't help that the standard procedure for handling Fedora installer
bugs is close them wontfix.

Alan