Thanks Roger, Zdenek,

I have my ZVOL on my NAS exposed as LUNs. The initiator were switched off and for unknown reason I found my NAS switched off as well.
It had run for long and I feared the worst (CPU/motherboard/etc). Instead once powered up everything started to work again but the LUNs that seemed to jeopardized.
I have many ZVOLs used by ESXi in which I have EVE-NG who uses LVM and such ZVOLs have the same size so I wanted to inspect them to check the hostname.

Now some LUNs started to work normally, some others still behave weirdly. I will run pvs on them with extra debugs to see what's going on.

Many thanks,

Alex

Le jeu. 23 sept. 2021 à 23:48, Roger Heflin <rogerheflin@gmail.com> a écrit :
If you have lvmetad running and in use then the lvm commands ask it
what the system has on it.

I have seen on random boots fairly separated systems (rhel7 versions,
and many years newer fedora systems) at random fail to find one or
more pv.s

I have disabled it at home, and in my day job we have also disabled
(across 20k+ systems) as we confirmed it had inconsistency issues
several times on a variety of our newest installs.

Stopping lvmetad and/or restarting it would generally fix it.    But
it was a source of enough random issues(often failure to mount on a
boot, so often issues that resulted in page-outs to debug)  and did
not speed things up much enough to be worth it even on devices with
>2000 SAN volumes.

On Thu, Sep 23, 2021 at 8:52 AM Zdenek Kabelac <zkabelac@redhat.com> wrote:
>
> Dne 22. 09. 21 v 18:48 alessandro macuz napsal(a):
> > fdisk correctly identifies the extended partition as 8e.
> > I wonder which kind of data lvmdiskscan and pvs use in order to list LVM
> > physical volumes.
> > Does PVS check some specific metadata within the partition without just
> > relying on the type of partition displayed by fdisk?
> >
> >
>
> Hi
>
> Yes - PVs do have header signature keeping information about PV attributes
> and also has the storage area to keep lvm2 metadata.
>
> Partition flags known to fdisk are irrelevant.
>
>
> Regards
>
> Zdenek
>
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>