[linux-lvm] LVM problem after upgrade to Ubuntu 16.04 (Part 2)

[Scott Hazelhurst]

Dear all

I sent the email below about three weeks ago. Today I upgraded another machine — I had exactly the same thing happen and I appear to have lost some LVM volumes

Hmm. At least I  know it’s a problem and can backup the LVM volumes before doing upgrade but it’s hugely annoying.

Scott




Dear all

I upgraded a server from Ubuntu 15.10 to 16.04. All went smoothly and the machine appeared in good state. However, there seems to be a problem with LVM. I have one volume group with several logical volumes. lvs showed all the logical volumes but only 2 of the 7 volumes were active (and appearing in /dev/mapper). 

I activated the other volumes using lvchange -ay and then I can see all logical volumes in /dev/mapper. 

However, there appear to a problem with some of the LVs which are used as the images for virtual machines (qemu-kvm). The VMs don't boot. Moreover, previously I could mount the sub-partitions of the LV by doing a kpartx -a on the logical volume. That no longer works (e.g. kpartx -l /dev/mapper/cloud-VNAME shows nothing, while it used to show the 3 partitions of the underlying virtual machine).

One of the LVs didn't have a problem -- this just contained a data disk.

This particular server is not a serious problem for me because  I can clone the VM from elsewhere, but I am about to start an upgrade of all our other machines and it will be very time-consuming if I have to do this with each machine.

Does anyone have any ideas about what went wrong? How the situation could be remedied

Thanks

Scott
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