Hello, > -----Original Message----- > From: redhat-list-bounces@xxxxxxxxxx > [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Richard Hobbs > Sent: 20 January 2005 14:23 > To: 'General Red Hat Linux discussion list' > Subject: RE: Soft-Raid Testing and other stuff... > > Hello, > > > -----Original Message----- > > From: redhat-list-bounces@xxxxxxxxxx > > [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Ed Wilts > > Sent: 20 January 2005 12:53 > > To: General Red Hat Linux discussion list > > Subject: Re: Soft-Raid Testing and other stuff... > > > > On Thu, Jan 20, 2005 at 11:17:01AM -0000, Richard Hobbs wrote: > > > > > I didn't duplicate the MBR as far as I know... I > > assumed that RAID 1 > > > > > (mirroring) mirrored the entire disk, sector for sector... > > > > Nope - it's partition by partition. That's why you did the > raidhotadd > > *per partition*. > > > > There are pros and cons to this approach - the biggest pro > is that you > > don't have to mirror the entire disk. The biggest con is > > that only data > > partitions are mirrored. > > > > For details on mirror the mbr, see: > > http://www.dur.ac.uk/a.d.stribblehill/mirrored_grub.html > > > > I haven't tried this but it's referenced by the online Red Hat > > documentation. > > > > > > > Also, if I then insert a blank disk, will it automatically > > > > > re-generate the > > > > > data onto it? Will I have to duplicate the MBR manually again? > > > > > > > > > You will always have to do this manually. Software RAID > knows nothing > > about the MBR - only partitions. > > So... am I correct in saying that if I run 'raidhotadd' on > all partitions to > get them mirrored correctly, and then I run the grub stuff to > install the > slave MBR, all is set and there's absolutely nothing else > that needs to be > done? In order to have a fully resilient system? > > I realise the BIOS might need to be altered to tell it to > boot from the > slave if the master is dead, but apart from that, is > everything done that > needs to be? > > Also, what are the exact steps to follow if the master disk dies in a > soft-raid 1 environment? > What are the steps to follow if the secondary disk dies in a > soft-raid 1 > environment? > > I assume they are fairly similar... Just replace the dead disk with an > identical blank one, boot up and reinstall the MBR once the automatic > reconstruction is done, right?? Or is it not that simple... > > Thanks again, > Hobbs. I have now solved this problem completely, so thanks to Ed Wilts and SpookyEddy from TechIMO.com. The answer was basically that I have to mirror the partitions independantly, and I have to duplicate the MBR. Also, if a disk fails, I have to manually re-create the partitions on the blank disk exactly as they are on the working disk. The full answer can be found here: http://unixforum.co.uk/667.html Thanks to all :-) Hobbs. -- Richard Hobbs (Systems Administrator) Toshiba Research Europe Ltd. - Speech Technology Group Web: http://www.toshiba-europe.com/research/ Email: richard.hobbs@xxxxxxxxxxxxxxxxx Tel: +44 1223 376964 Mobile: +44 7811 803377 _____________________________________________________________________ This e-mail has been scanned for viruses by MCI's Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.mci.com -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
