Re: A gmirror question.
Ok, that explains it. Thanks for the quick answers! BR Stefan ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: A gmirror question.
On Tuesday 28 October 2008 17:53:20 Stefan Moro wrote: > 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. It doesn't care about the device name. Geom modules that are loaded into the kernel, register a 'taste' function, with the geom(4) subsystem, that tastes if a provider is something they want to work with. Effectively, this taste function reads the last sector and checks if it has gmirror metadata. The geom system is the 'magician', which basically hands all providers to the loaded modules. -- Mel Problem with today's modular software: they start with the modules and never get to the software part. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: A gmirror question.
If I have understood things correctly, gmirror stores all relevant information about the mirror in the last sector on the provider. exactly. it doesn't matter how the disks are connected. all data is in last sector. for non-mirrored drives it's useful to use glabel to get the same ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: A gmirror question.
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 "[EMAIL PROTECTED]" 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. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
