> I've started updating systems to CentOS 7.6, and so far I have one > failure. > > This system has two peculiarities which might have triggered the > problem. The first is that one of the software RAID arrays on this > system is degraded. While troubleshooting the problem, I saw similar > error messages mentioned in bug reports indicating that sGNU/Linux > ystems would not boot with degraded software RAID arrays. The other > peculiar aspect is that the system uses dm-cache. > > Logs from some of the early failed boots are not available, but before I > completely fixed the problem, I was able to bring the system up once, > and captured logs which look substantially similar to the initial boot. > The content of /var/log/messages is here: > https://paste.fedoraproject.org/paste/n-E6X76FWIKzIvzPOw97uw > > The output of lsblk (minus some VM logical volumes) is here: > https://paste.fedoraproject.org/paste/OizFvMeGn81vF52VEvUbyg > > As best I can tell, the LVM tools were treating software RAID component > devices as PVs, and detecting a conflict between those and the assembled > RAID volume. When running "pvs" on the broken system, no RAID volumes > were listed, only component devices. At the moment, I don't know if the > LVs that were activated by the initrd were backed by component devices > or the RAID devices, so it's possible that this bug might corrupt > software RAID arrays. > > In order to correct the problem, I had to add a global_filter to > /etc/lvm/lvm.conf and rebuild the initrd (dracut -f): > global_filter = [ "r|vm_.*_data|", "a|sdd1|", "r|sd..|" ] > > This filter excludes the LVs that contain VM data, accepts "/dev/sdd1" > which is the dm-cache device, and rejects all other partitions on > SCSI(SATA) device nodes, as all of those are RAID component devices. > > I'm still working on the details of the problem, but I wanted to share > what I know now in case anyone else might be affected. > > After updating, look at the output of "pvs" if you use LVM on software > RAID. What exactly did `pvs' show and instead of what? Regards, Simon