geom mirror

Josef Karthauser joe at
Sat Mar 26 07:42:00 PST 2005

On Sat, Mar 26, 2005 at 01:16:30PM +0000, Josef Karthauser wrote:
> What is the relationship between geom mirror partitions and native ones,
> i.e. ad1s1 vs mirror/gm0s1?  The disk labels above look spookily
> similar, but I didn't set a disklabel on ad1s1 manually.
> With respect to booting do the first stage boot blocks know anything
> about gmirror partitions?  How is the linkage between native devices and
> gmirror devices done at boot time?

One more thing.  The reason I can't boot on /dev/ad1s1 is probably
because /dev/ad1s1a doesn't appear to be registered (hence the invalid
label problem I see at the stage one boot.)

# ls /dev/ad1*
/dev/ad1   /dev/ad1s1
# ls /dev/mirror
gm0s1  gm0s1a gm0s1b gm0s1c gm0s1d gm0s1e gm0s1f gm0s1g gm0s1h

jonah# gmirror list
Geom name: gm0s1
Components: 1
Balance: round-robin
Slice: 4096
SyncID: 1
ID: 3812009587
1. Name: mirror/gm0s1
   Mediasize: 122942291968 (114G)
   Sectorsize: 512
   Mode: r6w6e1
1. Name: ad1s1
   Mediasize: 122942292480 (114G)
   Sectorsize: 512
   Mode: r6w6e2
   State: ACTIVE
   Priority: 0
   SyncID: 1
   ID: 3349174391

Geom name: gm0s1.sync

What does DIRTY mean in this context?  Is that why ad1s1a isn't
appearing in /dev?

Josef Karthauser (joe at
FreeBSD (cvs meister, admin and hacker)
Physics Particle Theory (student)
================ An eclectic mix of fact and theory. =================
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