a gmirror disappears after adding gjournals to its partitions
kraduk at gmail.com
Tue Nov 23 21:57:29 UTC 2010
2010/11/23 CyberLeo Kitsana <cyberleo at cyberleo.net>
> On 11/22/2010 10:19 PM, perryh at pluto.rain.com wrote:
> > krad <kraduk at gmail.com> wrote:
> >> On 21 November 2010 06:10, <perryh at pluto.rain.com> wrote:
> > ...
> >>> ==== manually-created config files, while still in chroot after install
> >>> Fixit# cat /boot/loader.conf
> >>> geom_mirror_load="YES"
> >>> geom_journal_load="YES"
> >>> vfs.root.mountfrom="ufs:/dev/mirror/gm0a.journal"
> >>> vfs.root.mountfrom.options="rw"
> > ...
> >>> ==== output from kldstat, after booting the newly-installed system --
> >>> ==== and manually mounting the root FS -- showing that geom_mirror.ko
> >>> ==== did get loaded.
> >>> Id Refs Address Size Name
> >>> 1 6 0xc0400000 bb5504 kernel
> >>> 2 1 0xc0fb6000 14540 geom_journal.ko
> >>> 3 1 0xc0fcb000 16ed4 geom_mirror.ko
> > ...
> >> sounds silly but are you loading the gmirror kernel module via
> >> loader.conf
> > Yes, I'm even setting geom_mirror_load to "YES" before setting
> > geom_journal_load to "YES" (although I doubt the order of these
> > settings in loader.conf makes any difference).
> > If the kldstat Id numbers are assigned sequentially, it looks as
> > if geom_journal got loaded first and this may somehow be related
> > (although I don't entirely see how -- absent geom_mirror to make gm0
> > and its partitions visible, I'd think that geom_journal "should not"
> > be able to find its metadata at all).
> From what I've found, this is because there is no taste difference
> between a bsdlabel on a gmirror and a bsdlabel on a non-mirror.
> Since both gmirror and gjournal are greedy (they take exclusive access
> of their parent providers upon successful taste, and not upon exclusive
> access to their own providers like glabel), the first one to
> successfully taste and start is the winner; the other will never get to
> taste those devices.
> The trick here is to either make the two look different somehow (use a
> different geom that stores its metadata at the beginning of the
> provider, instead of the end, thus eliminating ambiguity in the bsdlabel
> taste), or to make the inner geom avoid the outer devices (hardcode
> provider names in metadata). Since you have an outer geom that provides
> a static name, hardcoding the name of the gmirror into the gjournal
> metadata shouldn't cause anything to break if your disks change places,
> Fuzzy love,
> Technical Administrator
> CyberLeo.Net Webhosting
> <CyberLeo at CyberLeo.Net>
> Furry Peace! - http://wwww.fur.com/peace/
I think what he is saying is slice it up 1st, then mirror the slices, and
slap the journal on top of that
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