[CentOS] LVM failure after CentOS 7.6 upgrade -- possible corruption

Thu Dec 6 05:57:55 UTC 2018
Gordon Messmer <gordon.messmer at gmail.com>

On 12/5/18 8:34 PM, Gordon Messmer wrote:
> I still can't reason why the lvm tools were scanning the component 
> volumes to begin with.

I think I've figured it out.  The new lvm-tools package appears to have 
broken support for detecting dm metadata version 0.90.  The update 
should be stable for anyone who did not upgrade from earlier versions of 
CentOS.  (I don't actually know when Anaconda last used 0.90 metadata)

On a working system with "verbose = 6" in lvm.conf:

# mdadm --detail /dev/md/primary
/dev/md/primary:
            Version : 1.2
...
# pvs
...
#device/dev-io.c:609           Opened /dev/sda3 RO O_DIRECT
#device/dev-io.c:359         /dev/sda3: size is 1951133696 sectors
#device/dev-io.c:658           Closed /dev/sda3
#filters/filter-mpath.c:196           /dev/sda3: Device is a partition, 
using primary device sda for mpath component detection
#device/dev-io.c:336         /dev/sda3: using cached size 1951133696 sectors
#device/dev-md.c:163           Found md magic number at offset 4096 of 
/dev/sda3.
#filters/filter-md.c:108           /dev/sda3: Skipping md component device
...


On the broken system:

# mdadm --detail /dev/md/primary
/dev/md/primary:
            Version : 0.90
...
# pvs
...
#device/dev-io.c:609           Opened /dev/sda3 RO O_DIRECT
#device/dev-io.c:359         /dev/sda3: size is 5858142208 sectors
#device/dev-io.c:658           Closed /dev/sda3
#filters/filter-mpath.c:196           /dev/sda3: Device is a partition, 
using primary device sda for mpath component detection
#filters/filter-partitioned.c:30            filter partitioned deferred 
/dev/sda3
#filters/filter-md.c:99            filter md deferred /dev/sda3
#filters/filter-persistent.c:346           filter caching good /dev/sda3