Date: Tue, 28 Oct 2008 14:13:00 -0700 From: Chris St Denis <chris@smartt.com> To: Stefan Moro <stefan.moro@gmail.com> Cc: freebsd-questions@freebsd.org Subject: Re: A gmirror question. Message-ID: <4907805C.3080705@smartt.com> In-Reply-To: <2961fef0810280953g48b5ea28y8aebf58bd8e8afb7@mail.gmail.com> References: <2961fef0810280953g48b5ea28y8aebf58bd8e8afb7@mail.gmail.com>
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Stefan Moro wrote: > Hi! > > I've got a question regarding the way that gmirror identifies what > "components" (if that is the right term) are included in a mirror. > > I recently created a mirror over two disks, ad2 and ad4. After some > bios changes (activating PATA) these devices were changed to ad6 and > ad10 respectively. > The "magic" thing (which probably isn't so magic =) ) here is that > after reboot, gmirror still managed to identify the mirror, now using > ad6 and ad10. > > If I have understood things correctly, gmirror stores all relevant > information about the mirror in the last sector on the provider. > > So I guess one possible solution is that gmirror ,during startup, > scans all disks/slices for this magic sector and then "starts" the > mirror. > But if this is the case, how does gmirror know that it should use (in > my example above) ad10 and not ad4 as the additional disk in the > mirror. > Or does gmirror use something else than the /dev entries to address disks?? > > I'm just curious how gmirror does this. > > > BR Stefan > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.org" > I don't know the technical details of the internal working of gmirror, but it likely uses the volume serial number or other such identifier.
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