Re: GPT missing after controller swap (wd to ld)

[Louis Guillaume <louis%zabrico.com@localhost>]

On 10/10/16 12:26 PM, Christos Zoulas wrote:
> On Oct 10, 11:35am, louis%zabrico.com@localhost (Louis Guillaume) wrote:
> -- Subject: Re: GPT missing after controller swap (wd to ld)
>
> | On 10/10/16 8:14 AM, Christos Zoulas wrote:
> | > In article <4c31b2ab-3161-9dc1-2d2b-74278c891065%zabrico.com@localhost>,
> | > Louis Guillaume  <louis%zabrico.com@localhost> wrote:
> | >> Hi,
> | >>
> | >> On NetBSD 7.0_STABLE, i386, (from earlier this year) I had configured a
> | >> couple of disks with GPTs and then switched controllers (wd1 now shows
> | >> up as ld1) and now the GPT appears to have gone missing. However my
> | >> wedges are still there...
> | >>
> | >> # gpt show ld1
> | >> gpt: error: map entry doesn't fit media
> | >> gpt: unable to open device 'rld1d': No such file or directory
> | >>
> | >> # dkctl ld1 listwedges
> | >> /dev/rld1d: 2 wedges:
> | >> dk0: boot0, 524288 blocks at 128, type: ffs
> | >> dk1: disk0, 3906504704 blocks at 524416, type: raidframe
> | >>
> | >> The first wedge is intended to just hold a kernel and emergency root
> | >> file system for booting. The root file system is on a raid array built
> | >> with dk1 (and others). I'm currently booted off a separate disk because
> | >> the bootmenu did not include the boot.cfg "installboot"-ed to ld1.
> | >>
> | >> Did something in the BIOS overwrite the GPT? How to recover?
> | >
> | > Can you try gpt show /dev/rld1d? Also show your dmesg?
> | >
> | > christos
> | >
> | >
> |
> |
> | Hi Christos,
> |
> | The gpt output is similar but not identical...
> |
> | # gpt show /dev/rld1d
> | gpt: error: map entry doesn't fit media
> | gpt: unable to open device 'rld1d': Undefined error: 0
> |
> | Also /dev/dk3 will not reconstruct on the raid (raidctl -R /dev/dk3
> | raid0), leaving these messages...
> |
> | raid0: initiating in-place reconstruction on column 1
> | raid0: IO failed after 5 retries.
> | raid0: IO failed after 5 retries.
> | raid0: Recon read failed: 22
> | raid0: reconstruction failed.
> |
> | But no low-level (ld or twa) IO messages.
> |
> | At this point I'm thinking of this procedure for recovery...
> |
> |     o Wipe ld2 and re-partition
> |     o Rebuild a new raid on ld2 (which has dk3)
> |     o Copy everything over
> |     o Boot from the new raid disk
> |     o Wipe ld1
> |     o Rebuild the raid with the new ld1
> |
> | Relevant parts of the dmesg.boot are below. Thanks for looking!
>
> Before you do anything, can you please rebuild the gpt binary from
> HEAD and see what that prints?
>
> christos

Pretty sure I did this right. My src/ tree is from the netbsd-7 branch. 
I did the following. Hopefully this is enough to get what you're looking 
for...

$ cd /usr/src/sbin/gpt
$ cvs up -A -dP
cvs update: Updating .
P Makefile
P add.c
P backup.c
P biosboot.c
P create.c
P destroy.c
cvs update: `drvctl.c' is no longer in the repository
P gpt.8
P gpt.c
P gpt.h
U gpt_private.h
P gpt_uuid.c
P gpt_uuid.h
U header.c
P label.c
U main.c
P map.c
P map.h
P migrate.c
P recover.c
P remove.c
P resize.c
P resizedisk.c
P restore.c
P set.c
P show.c
P type.c
P unset.c

$ TOOLDIR=/usr/obj/TOOLDIR.i386 make

.....

# ./gpt show /dev/rld1d
gpt: /dev/rld1d: map entry doesn't fit media

# ./gpt show ld1
gpt: /dev/rld1d: map entry doesn't fit media


# ./gpt -vvvv show ld1
/dev/rld1d: mediasize=1999988850688; sectorsize=512; blocks=3906228224
/dev/rld1d: MBR not found at sector 0
/dev/rld1d: Pri GPT at sector 1
/dev/rld1d: GPT partition: type=ffs, start=128, size=524288
/dev/rld1d: GPT partition: type=raid, start=524416, size=3906504704
gpt: /dev/rld1d: map entry doesn't fit media