Re: Mirror one 72 gig disk on another.
From: Darren Dunham (ddunham_at_redwood.taos.com)
Date: Wed, 22 Sep 2004 15:23:38 GMT
ds <firstname.lastname@example.org> wrote:
> "Juhan Leemet" <email@example.com> wrote in message
>> >> prtvtoc /dev/rdsk/cAtBdCs2 | fmthard -s - /dev/rdsk/cXtYdZs2
>> >> Now, what *I* would like to know is, for SURE does this ALSO
>> >> make diskb bootable, i.e. copy the boot record?? My
>> >> understanding is that it does.
>> > No. All 'fmthard' does is to arrange the slices in the VTOC (rather
>> > like 'format' does).
> This is getting interesting (again ;-).
> Since prtvtoc | fmthard arranges the slices in the VTOC, like format
> does, does newfs then need to be applied to all slices of the
> pre-mirror diskb before mirroring? Or, does mirroring *also* create
> the ufs newfs slices?
'newfs' would create a new, blank filesystem. But that's not what you
want. You just want a copy of your existing filesystem.
As the mirror syncs up, all the data in the slice (which includes the
existing filesystem) will be copied. Running 'newfs' to create another
filesystem beforehand is just a waste of time, since it will be
overwritten by the resynchronization.
> Okay, if one forgets to use installboot before mirroring, can it be
> done after mirroring? And yet, isn't the bootblock part of the
> root slice (typcially s0)?
> I have read the Sun doc, and upon reflection, a lot of this is still
> not very clear. (Or, maybe I missed the nuances?)
My assumption was that the resynchronization would copy not only the
filesystem, but also the boot blocks. I don't know that the documents
make explicit which blocks are not synced. That would have implications
for raw database files, but I would assume most of them would also skip
the first 16 blocks, just like a filesystem.
-- Darren Dunham firstname.lastname@example.org Senior Technical Consultant TAOS http://www.taos.com/ Got some Dr Pepper? San Francisco, CA bay area < This line left intentionally blank to confuse you. >