Re: md device renaming

[Neil Brown <neilb@suse.de>]

On Sun, 12 Dec 2010 19:53:22 -0700 "Patrick H." <linux-raid@feystorm.net>
wrote:

> Sent: Sun Dec 12 2010 19:49:20 GMT-0700 (Mountain Standard Time)
> From: Neil Brown <neilb@suse.de>
> To: Patrick H. <linux-raid@feystorm.net> linux-raid@vger.kernel.org
> Subject: Re: md device renaming
> > On Sun, 12 Dec 2010 19:37:05 -0700 "Patrick H." <linux-raid@feystorm.net>
> > wrote:
> >
> >   
> >> So, every time I start up this md device with a specified name, it 
> >> renames itself to something else.
> >>
> >> When I first created the array, I typo'd the name as 'nas01:isci-sdb1' 
> >> (should be nas01:iscsi-sdb1). And now every time I assemble it with the 
> >> correct name, it renames itself:
> >>
> >> # /sbin/mdadm -A /dev/md/nas01:iscsi-sdb1 --uuid 
> >> abddf4ea:06524e68:8e2b8f4e:1b24c56d -R -U name
> >> mdadm: /dev/md/nas01:iscsi-sdb1 has been started with 2 drives (out of 3)
> >> # ls /dev/md/nas*
> >> /dev/md/nas01:isci-sdb1
> >> # ls /dev/disk/by-id/md-name*
> >> /dev/disk/by-id/md-name-nas01:iscsi-sdb1
> >> # mdadm -D /dev/md/nas01:isci-sdb1|grep Name
> >>            Name : nas01:iscsi-sdb1  (local to host nas01)
> >>
> >>
> >> So, notice how it says it started it as "nas01:iscsi-sdb1", however once 
> >> its up and I do the `ls`, it has the original name on it. I've tried -U 
> >> name to update the name on it when its assembled, but doesnt do a thing.
> >>
> >> Am I missing something here. Shouldnt it be assembling itself with the 
> >> specified name I gave it, not the original name? And then how do I 
> >> update it so the name in the metadata is correct?
> >> (and yes I know its missing a drive, I'm testing some stuff out)
> >>     
> >
> > It is assembling it with the name you give it, but the name stored in the
> > metadata is still the old name.
> > Try adding --update=name to the --assemble command.
> >
> > NeilBrown
> > --
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> >   
> How is it assembling with the name I gave it? It says 
> "/dev/md/nas01:iscsi-sdb1 has been started", but it really is using 
> "nas01:isci-sdb1". Even if it is going to use the name I created it 
> with, it should say that instead of the name I provided on the assemble 
> command.
> And I did add the update argument, see the '-U name' option on the end 
> of the command above.


Sorry, I obviously didn't read properly...
It must be getting the old name from somewhere.
I would
 - stop the array
 - use "mdadm -E" to examine each device and see what name is recorded.
 - look in /etc/mdadm.conf to see what name is there.
 - check /dev/.mdadm/map or possible /var/run/mdadm/map to see if the
   array is mentioned in there (it shouldn't be).

to find out where the old name still is.  Then at least you know what needs
fixing.
Just for completeness: what version of mdadm are you using?

NeilBrown