gmirror gm0 destroyed on shutdown; GPT corrupt
mexas at bristol.ac.uk
Mon Jun 29 09:39:03 UTC 2009
On Thu, Jun 25, 2009 at 09:41:13AM -0700, Marcel Moolenaar wrote:
> On Jun 25, 2009, at 4:02 AM, Anton Shterenlikht wrote:
> > dev_taste(DEV,mirror/gm0)
> > g_part_taste(PART,mirror/gm0)
> > GEOM: mirror/gm0: the secondary GPT table is corrupt or invalid.
> > GEOM: mirror/gm0: using the primary only -- recovery suggested.
> > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> You created the mirror after the GPT, which means you destroyed
> the GPT backup header. gmirror uses the last sector on the disk
> for metadata and that by itself is a cause for various problems.
So, gmirror cannot be used on ia64 to mirror the boot disk?
Because on ia64 the last sector always contains secondary GPT.
I take it the RAID1 section, 19.4, in FBSD user manual,
was written with i386 or alpha architecture in mind.
> It's better to use gmirror per partition.
how? Is it in the manual? any link?
> > #echo 'geom_mirror_load="YES"' >> /boot/loader.conf
> Is /boot a symlink for /efi/boot?
lrwxr-xr-x 1 root wheel 8 Jun 25 10:44 boot -> efi/boot
> > And when the system is rebooted, there is no /dev/mirror anymore.
> You could run into a race condition between GPT and gmirror and
> GPT winning (again the result of gmirror using the last sector
> on a disk for metadata).
> Alternatively, make sure gmirror got loaded at boot.
Id Refs Address Size Name
1 3 0xe000000004000000 ff9c08 kernel
2 1 0xe000000004ffa000 3c830 geom_mirror.ko
It's not that I desperately need to mirror a boot disk, it just that
gmirror looked so easy in the manual, I wanted to give it a go.
Perhaps I can just do a block copy to the second disk, say once a day,
and have it as a backup.
Could you also possibly comment on gvinum on ia64?
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