[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.

[David Teigland]

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.

[Xen]

Post by David Teigland

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...

[Zdenek Kabelac]

Post by David Teigland

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

[Xen]

Post by Zdenek Kabelac
You can always 'fix it' you way.
Just setup device filter in lvm.conf so you either see diskA or diskB
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.

[Xen]

Post by David Teigland

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.