Re: How to recreate a dmraid RAID array with mdadm

[Neil Brown <neilb@suse.de>]

On Wed, 17 Nov 2010 22:03:41 -0500
Mike Viau <viaum@sheridanc.on.ca> wrote:

> 
> > On Thu, 18 Nov 2010 13:32:47 +1100 <neilb@suse.de> wrote:
> > > ./mdadm -Ss
> > >
> > > mdadm: stopped /dev/md127
> > >
> > >
> > > ./mdadm -Asvvv
> > >
> > > mdadm: looking for devices for further assembly
> > > mdadm: no RAID superblock on /dev/dm-3
> > > mdadm: /dev/dm-3 has wrong uuid.
> > >  want UUID-084b969a:0808f5b8:6c784fb7:62659383
> > > Segmentation fault
> >
> > Try this patch instead please.
> 
> Applied new patch and got:
> 
> ./mdadm -Ss
> 
> mdadm: stopped /dev/md127
> 
> 
> ./mdadm -Asvvv
> mdadm: looking for devices for further assembly
> mdadm: no RAID superblock on /dev/dm-3
> mdadm: /dev/dm-3 has wrong uuid.
>  want UUID-084b969a:0808f5b8:6c784fb7:62659383
>  tst=0x10dd010 sb=(nil)
> Segmentation fault

Sorry... I guess I should have tested it myself..

The
   if (tst) {

Should be
 
   if (tst && content) {

NeilBrown


> 
> 
> Again tried various buffer sizes (segfault above was with char buf[200];)
> 
> 
> if (ident->uuid_set && (!update || strcmp(update, "uuid")!= 0) &&
>     (!tst || !tst->sb ||
>      same_uuid(content->uuid, ident->uuid, tst->ss->swapuuid)==0)) {
>         if (report_missmatch) {
>              char buf[1<<16];
>                 fprintf(stderr, Name ": %s has wrong uuid.\n",
>                         devname);
>           fprintf(stderr, " want %s\n", __fname_from_uuid(ident->uuid, 0, buf, ':'));
>              fprintf(stderr, " tst=%p sb=%p\n", tst, tst?tst->sb:NULL);
>              if (tst) {
>                        fprintf(stderr, " have %s\n", __fname_from_uuid(content->uuid, 0, buf, ':'));
>                         fprintf(stderr, " metadata=%s\n", tst->ss->name);
>              }
>     }
>         goto loop;
> }
> 
>