Arch Linux

PGNd

Member

Registered: 2016-02-24

Posts: 1

Arch Xen PVHVM DomU reports "appeared twice with different sysfs paths

I've installed Arch in a Xen PVHVM DomU.

In the Guest I've set up fstab

	cat /etc/fstab
	 UUID="8168-31CD" /boot/efi  vfat  umask=0002,utf8=true,x-systemd.automount,noauto  0 2
	 LABEL=BOOT /boot  ext4  acl,user_xattr  1 2
	 LABEL=ROOT /      ext4  acl,user_xattr  1 1
	 LABEL=SWAP swap   swap  defaults        0 0

The guest boots & is accessible & funcitonal/

Checking the Xen boot logs for the Guest, I notice

 ...
 [   35.121419] systemd[1]: Mounting /boot/efi...
 [   35.127141] systemd[1]: dev-disk-by\x2dlabel-EFI.device: Dev dev-disk-by\x2dlabel-EFI.device appeared twice with different sysfs paths /sys/devices/pci0000:00/0000:00:05.0/ata3/host2/target2:0:0/2:0:0:0/block/sda/sda1 and /sys/devices/vbd-51712/block/xvda/xvda1
 [   35.140915] systemd[1]: dev-disk-by\x2dpartuuid-d518f809\x2db874\x2d4cea\x2d9576\x2d85ce52e6925d.device: Dev dev-disk-by\x2dpartuuid-d518f809\x2db874\x2d4cea\x2d9576\x2d85ce52e6925d.device appeared twice with different sysfs paths /sys/devices/pci0000:00/0000:00:05.0/ata3/host2/target2:0:0/2:0:0:0/block/sda/sda1 and /sys/devices/vbd-51712/block/xvda/xvda1
 [   35.164678] systemd[1]: dev-disk-by\x2duuid-8168\x2d31CD.device: Dev dev-disk-by\x2duuid-8168\x2d31CD.device appeared twice with different sysfs paths /sys/devices/pci0000:00/0000:00:05.0/ata3/host2/target2:0:0/2:0:0:0/block/sda/sda1 and /sys/devices/vbd-51712/block/xvda/xvda1
 [   35.258386] systemd[1]: Mounted /boot/efi.
 ...

Since the Guest is PVHVM, drive names are presented internally to the client as both /dev/hdX and /dev/xvdX. E.g.,

blkid | grep SWAP
 /dev/xvdf1: LABEL="SWAP" UUID="7cadc6cb-20bd-45fd-8880-66c895b4f25f" TYPE="swap" PARTUUID="dfcc75f8-609e-458d-9bf6-a700eb90f020"
 /dev/sdc1: LABEL="SWAP" UUID="7cadc6cb-20bd-45fd-8880-66c895b4f25f" TYPE="swap" PARTUUID="dfcc75f8-609e-458d-9bf6-a700eb90f020"
 /dev/disk/by-label/SWAP: LABEL="SWAP" UUID="7cadc6cb-20bd-45fd-8880-66c895b4f25f" TYPE="swap" PARTUUID="dfcc75f8-609e-458d-9bf6-a700eb90f020"

Unlike this report @ Arch,

  [S] Systemd device dev-disk-by\{stuff} appeared twice with sysfs diff
  https://bbs.archlinux.org/viewtopic.php?id=196640&p=2

this is not an issue of incorrect/inadvertent duplicate GPT UUIDs not properly randomized at time of a GPT partition table clone.

Is this warning/error in fact a problem?

If so, what's the fix?

If not, can this check be disabled/silenced?