Here’s something interesting that may be relevant, given the note from “man pvcreate”:
> rbthomas@small:~$ lsblk -t > NAME ALIGNMENT MIN-IO OPT-IO PHY-SEC LOG-SEC ROTA SCHED > RQ-SIZE RA WSAME > sda 0 4096 33553920 4096 512 1 mq-deadline > 60 128 0B > `-sda1 0 4096 33553920 4096 512 1 mq-deadline > 60 128 0B > |-small-swap -1 4096 0 4096 512 1 > 128 128 32M > |-small-root -1 4096 0 4096 512 1 > 128 128 32M > `-small-home -1 4096 0 4096 512 1 > 128 128 32M > mmcblk2 0 512 0 512 512 0 mq-deadline > 128 128 0B > |-mmcblk2p1 0 512 0 512 512 0 mq-deadline > 128 128 0B > `-mmcblk2p2 0 512 0 512 512 0 mq-deadline > 128 128 0B > rbthomas@small:~$ Note the alignment values of “-1” for the lvm entries but not for the GPT partition or the whole disk. Why do you suppose that is? Rick On Jul 28, 2018, at 12:26 AM, Rick Thomas <rbtho...@pobox.com> wrote: > > On Jul 27, 2018, at 8:19 PM, David Wright <deb...@lionunicorn.co.uk> wrote: > >> On Fri 27 Jul 2018 at 18:46:02 (-0700), Rick Thomas wrote: >>> When booting, I get 12 error messages similar to the following (three >>> groups of four, each group with a different “start” value and corresponding >>> minor device) >>> >>>> Jul 24 03:40:08 small kernel: device-mapper: table: 254:1: adding target >>>> device sda1 caused an alignment inconsistency: physical_block_size=4096, >>>> logical_block_size=512, alignment_offset=0, start=33553920 >>> >>> Can anyone tell me what it means and what I should do about it? >> >> That's the same message as I reported on an MBR disk in >> https://lists.debian.org/debian-user/2018/02/msg00466.html >> >> The post gives full details of the partitioning and the >> creation of the encrypted filesystem which precede getting >> the messages (in pairs). >> >> There were no follow-ups. > > Googling the contents of the subject line of this post gives: > > > https://unix.stackexchange.com/questions/340484/device-mapper-table-alignment-inconsistency > > which is slightly helpful. > > Something else that is interesting is the following from “man pvcreate”: > >> If a device is a 4KiB sector drive that compensates for windows partitioning >> (sector 7 is the lowest aligned logical >> block, the 4KiB sectors start at LBA -1, and consequently sector 63 >> is aligned on a 4KiB boundary) manually account >> for this when initializing for use by LVM. >> pvcreate --dataalignmentoffset 7s /dev/sdb > > Is it possible that I have such a device? > > Enjoy! > Rick