FreeBSD boot menu is missing

Peter Steele psteele at maxiscale.com
Wed Nov 26 16:56:06 PST 2008


>He had you install a stock MBR on the second disk. You never copied
>the boot loader from the first disk, so that's what you're going to
>use when you boot from the second disk. You need to install the boot
>block you want on the second disk. Which probably means
>boot0. boot0cfg will do that for you. You probably want
>       boot0cfg -B -s 1 <diskdevice> 	# The device - ad1, not the
slice!

Okay, that makes sense. That's an easy change to my script.

>Um, no. He reduced the size of one partition because he's overly
>paranoid about gmirror failing to recognize the providers properly,
>which forces him to dump and restore one partition - which leads to
>doing them all to get them on one disk. If you don't need to resize
>the partitions, you can just labelling the disk you're already using.
>Once you've done that, you can gmirror insert the second drive into
>the mirror, and it will resilver the second drive while providing full
>access to the first one. No need to copy any data at all.

Man, I wish I'd known this. I built a whole automated framework around
this, assuming you couldn't set up the initial mirror drive with a live
file system. I'll have to try your solution; it is definitely the way to
go. We are dealing with identical size drives as well so this shouldn't
be a problem.

>His analysis of the choices is pretty shallow as well. He lets wanting
>to use different-sized disks dominate the analysis, which is great if
>you're building your mirror with disks from the parts bin. I tend to
>by drives to pairs if I want to mirror them, so that's
>immaterial. Once that's gone, mirroring a full disk slice just doesn't
>make sense at all - either mirror the entire disk (to get the MBR), or
>mirror the partitions in the slice (for extra flexibility and less
>painful resilvering).

We don't want to mirror the whole drive, just the OS partitions. I
decided to go with the full slice mirroring because of what was
described in this link. If mirroring the partitions in the slice is the
better way to go, then that's fine my me. 

>Better instructions for getting a full-disk mirror can be found here:
>http://www.onlamp.com/pub/a/bsd/2005/11/10/FreeBSD_Basics.html

I look forward to reading this. Thanks for the help!



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