Comment 18 for bug 1611945

I'm not sure of the ramifications of these error messages but I can
confirm they are still there.

On Mon, Feb 12, 2018 at 8:35 AM, Norman Henderson <email address hidden> wrote:
> Ladies and Gentlemen, The technical stuff is way over my head but I am
> getting the same syslog errors and the same inconsistent device paths on
> an HP Proliant ML110 G7 with Ubuntu 16.04.3 kernel 4.4.0-98-generic.
>
> It seems clear that no-one is taking ownership of this to fix it in an
> actual update that ordinary people like me can install in the normal
> course of system updates. The nature of open source software I guess.
>
> However could someone please let me know:
> - is this just an annoying message that won't be fixed, or are there operational implications?
> - if there are implications, are they serious?
> - if they are serious, could you explain (or point me at a resource that explains) in detail, how to install the patch provided. I've never done that before.
>
> Thank you in advance!
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1611945
>
> Title:
> /dev/disk/by-path not properly populated for (e)SATA port multiplier
> disks
>
> Status in systemd package in Ubuntu:
> Confirmed
>
> Bug description:
> We have a just-installed Ubuntu 16.04 LTS machine with a number of
> disks behind port-multiplier eSATA ports, all of them driven by a SiI
> 3124 controller (sata_sil24 kernel driver). Our machine sees all disks
> on all channels, however under 16.04 only one disk from each channel
> shows up in /dev/disk/by-path/ (all disks show up in /dev/disk/by-id
> and /dev/disk/by-uuid). For our usage this is a severe defect because
> we rotate disks in and out of the external enclosure and rely on
> mounting specific slots in the external enclosure through /dev/disk
> /by-path.
>
> This did not happen in Ubuntu 12.04 LTS, the release that this machine
> was previously running.
>
> According to 'udevadm info --export-db' and 'udevadm test-builtin
> path_id' and so on, systemd's udev stuff is assigning all drives
> behind the same port the same disk/by-path data (ID_PATH et al). In
> 'udevadm info /sys/block/sdX', the 'P:' and 'E: DEVPATH=' values show
> a difference in the target portion of PCI path, eg:
>
> P: /devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:00.0/ata1/host0/target0:0:0/0:0:0:0/block/sda
> P: /devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:00.0/ata1/host0/target0:1:0/0:1:0:0/block/sdb
>
> However the 'S: disk/by-path', 'E: DEVLINKS=', and 'E: ID_PATH'
> portions do not. For both devices above, we see:
>
> S: disk/by-path/pci-0000:02:00.0-ata-1
> E: ID_PATH=pci-0000:02:00.0-ata-1
>
> Naturally only one device can have a /dev/disk/by-
> path/pci-0000:02:00.0-ata-1 symlink, so instead of four disks per
> channel in /dev/disk/by-path we see one.
>
> Ubuntu release: 16.04
>
> Package versions from 'apt-cache policy udev systemd':
> udev:
> Installed: 229-4ubuntu7
> systemd:
> Installed: 229-4ubuntu7
>
> 'journalctl -b' reports that during boot systemd does report some
> 'appeared twice with different sysfs paths' notes, eg:
>
> Aug 10 13:34:21 verdandi systemd[1]: dev-disk-by\x2dpath-
> pci\x2d0000:02:00.0\x2data\x2d1\x2dpart1.device: Dev dev-disk-by
> \x2dpath-pci\x2d0000:02:00.0\x2data\x2d1\x2dpart1.device appeared
> twice with different sysfs paths
> /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:00.0/ata1/host0/target0:3:0/0:3:0:0/block/sdd/sdd1
> and
> /sys/devices/pci0000:00/0000:00:01.0/0000:01:00.0/0000:02:00.0/ata1/host0/target0:0:0/0:0:0:0/block/sda/sda1
>
> However it doesn't seem to be reporting this for all port-multiplier
> drives and their partitions.
>
> If it would be useful I can attach full 'udevadm info --export-db'
> output or the like.
>
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