[linux-lvm] how to change UUID of PV of duplicate partition (followup)

[linux-lvm] how to change UUID of PV of duplicate partition (followup)

[Xen]

I mean,

This is what I mean:

   Found duplicate PV 3U9ac3Ah5lcZUf03Iwm0cgMMaKxdflg0: using /dev/sdb4 
not /dev/sdc4
   Using duplicate PV /dev/sdb4 without holders, replacing /dev/sdc4
   Volume group containing /dev/sdb4 has active logical volumes
   Physical volume /dev/sdb4 not changed
   0 physical volumes changed / 1 physical volume not changed

It immediately replaced the good PV with the bad PV (that I was trying 
to change) so I cannot actually get to the "bad" PV (which is duplicate) 
to change it without booting an external system in which I can effect 
one disk in isolation.

But, after running that command my root filesystem was now mounted 
read-only instantly so even just attaching the disk basically causes the 
entire system to instantly fail.

Real good right.

Probably my entire fault right :-/.

"Let's cause this system to crash, we'll attach a harddisk." "Job done!"

Actually I guess in this case it replaced the bad with the good but 
behind the scenes something else happened as well. This time it is 
hiding /dev/sdc4, the other time it was hiding /dev/sdb4, it seems to be 
random.

Basically any eSata system that a disk gets attached to could cause the 
operating system to fail. The same would probably be true of regular USB 
disks.

Even inserting a USB stick could crash a system like this.

Re: [linux-lvm] how to change UUID of PV of duplicate partition (followup)

[David Teigland]

On Fri, Jan 06, 2017 at 08:10:20PM +0100, Xen wrote:
> This is what I mean:
> 
>   Found duplicate PV 3U9ac3Ah5lcZUf03Iwm0cgMMaKxdflg0: using /dev/sdb4 not
> /dev/sdc4

The handling of duplicate PVs has been entirely redone in recent versions.
The problems you are having are well known and should now be fixed.

Re: [linux-lvm] how to change UUID of PV of duplicate partition (followup)

[Xen]

David Teigland schreef op 06-01-2017 20:19:
> On Fri, Jan 06, 2017 at 08:10:20PM +0100, Xen wrote:
>> This is what I mean:
>> 
>>   Found duplicate PV 3U9ac3Ah5lcZUf03Iwm0cgMMaKxdflg0: using /dev/sdb4 
>> not
>> /dev/sdc4
> 
> The handling of duplicate PVs has been entirely redone in recent 
> versions.
> The problems you are having are well known and should now be fixed.

Oh right, I was going to write my LVM version, but did not manage to 
produce it yet, sorry :p.

Good to know. Yeah I am using 16.04 from Ubuntu's version.

   LVM version:     2.02.133(2) (2015-10-30)
   Library version: 1.02.110 (2015-10-30)
   Driver version:  4.34.0

Sigh... I guess I'll have to make some time to start using a recent 
version then on this system. Perhaps it was due time. Always these old 
versions...

Re: [linux-lvm] how to change UUID of PV of duplicate partition (followup)

[Zdenek Kabelac]

Dne 6.1.2017 v 20:21 Xen napsal(a):
> David Teigland schreef op 06-01-2017 20:19:
>> On Fri, Jan 06, 2017 at 08:10:20PM +0100, Xen wrote:
>>> This is what I mean:
>>>
>>>   Found duplicate PV 3U9ac3Ah5lcZUf03Iwm0cgMMaKxdflg0: using /dev/sdb4 not
>>> /dev/sdc4
>>
>> The handling of duplicate PVs has been entirely redone in recent versions.
>> The problems you are having are well known and should now be fixed.
>
> Oh right, I was going to write my LVM version, but did not manage to produce
> it yet, sorry :p.
>
> Good to know. Yeah I am using 16.04 from Ubuntu's version.
>
>   LVM version:     2.02.133(2) (2015-10-30)
>   Library version: 1.02.110 (2015-10-30)
>   Driver version:  4.34.0
>
> Sigh... I guess I'll have to make some time to start using a recent version
> then on this system. Perhaps it was due time. Always these old versions...
>
> _______________________________________________


You can always 'fix it' you way.

Just setup  device filter in  lvm.conf  so you either  see diskA or diskB

In you particular  case:

  filter = [ "r|/dev/sdb4|" ]

or

  filter = [ "r|/dev/sdc4|" ]


And set/change things with your existing lvm2 version....

Regards

Zdenek

Re: [linux-lvm] how to change UUID of PV of duplicate partition (followup)

[Xen]

David Teigland schreef op 06-01-2017 20:19:
> On Fri, Jan 06, 2017 at 08:10:20PM +0100, Xen wrote:
>> This is what I mean:
>> 
>>   Found duplicate PV 3U9ac3Ah5lcZUf03Iwm0cgMMaKxdflg0: using /dev/sdb4 
>> not
>> /dev/sdc4
> 
> The handling of duplicate PVs has been entirely redone in recent 
> versions.
> The problems you are having are well known and should now be fixed.

Thank you. I've installed the version from Ubuntu 16.10 and the 
vgimportclone command worked fine now :).

Still gives those same errors mostly (the duplication detection output) 
and provides no other success output that made me a little scared,

   WARNING: PV 3U9ac3-Ah5l-cZUf-03Iw-m0cg-MMaK-xdflg0 on /dev/sdc4 was 
already found on /dev/sdb4.
   WARNING: PV 3U9ac3-Ah5l-cZUf-03Iw-m0cg-MMaK-xdflg0 prefers device 
/dev/sdb4 because device is used by LV.
   WARNING: PV 3U9ac3-Ah5l-cZUf-03Iw-m0cg-MMaK-xdflg0 on /dev/sdc4 was 
already found on /dev/sdb4.
   WARNING: PV 3U9ac3-Ah5l-cZUf-03Iw-m0cg-MMaK-xdflg0 prefers device 
/dev/sdb4 because of previous preference.
   Couldn't find device with uuid ZvvuxB-8sgu-quBO-ZQDW-zKr8-pYzI-qF1ygK.

Particularly because one half of a mirrored LV is always missing :p so I 
get that last line too, but because I don't memorize my PV UUIDs I'm 
always a bit uncertain what it could mean :P.

But the output from lvs indicated that the result was achieved:

   msata-lv coll  -wi-------  28,91g
   raid-lv  coll  -wi------- 464,36g
   msata-lv coll2 -wi-ao----  28,91g
   raid-lv  coll2 -wi-ao---- 464,36g

(I renamed my vgs in reverse after the fact).

The above is a terrible design choice I made lol. Instead of creating an 
extra partition which would have meant an extended partition to hold 2 
distinct PVs, I embedded them in a single partition using a single PV.

The amount of trouble that gives.

Anyway, thank you for your dear answers, previously I was told it was 
all my fault because I was stupid and didn't know how to use the tools 
properly.

So thanks for that, cya.

Re: [linux-lvm] how to change UUID of PV of duplicate partition (followup)

[Xen]

Zdenek Kabelac schreef op 06-01-2017 21:06:

> You can always 'fix it' you way.
> 
> Just setup  device filter in  lvm.conf  so you either  see diskA or 
> diskB
> 
> In you particular  case:
> 
>  filter = [ "r|/dev/sdb4|" ]
> 
> or
> 
>  filter = [ "r|/dev/sdc4|" ]
> 
> 
> And set/change things with your existing lvm2 version....

Oh right, thank you man. I was looking for that but barring an option 
available on pvchange or vgimportclone itself I just decided to go the 
easy package upgrade route with David's help or suggestion.

I knew that should have been possible, so thanks. I just hadn't gotten 
around to diving into the config file yet. Much appreciated.

Regards.