kernel-packages team mailing list archive

[Rafael David Tinoco <rafael.tinoco@xxxxxxxxxxxxx>]

Per Dan's request... second test is what he asked me to test -> It
reasonably mitigates the issue:

#
# Precise latest -updates kernel
#

inaddy@sf00068947precise:~$ uname -a
Linux sf00068947precise 3.2.0-89-generic #127-Ubuntu SMP Tue Jul 28 09:28:15 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

inaddy@alien:teste$ ./teste.sh
% RUN: 1
+ Creating disk 0: /dev/vdb
+ Creating disk 1: /dev/vdc
! Starting virtual machine
! Adding disk 0: /dev/vdb
! Adding disk 1: /dev/vdc
! Waiting virtual machine network to be up
! Checking if disk is online:
* Found 0 extra disks online
$ Missing disk(s) exiting

inaddy@alien:teste$ virsh shutdown sf00068947precise
Domain sf00068947precise is being shutdown

inaddy@alien:teste$ ./teste.sh
% RUN: 1
+ Creating disk 0: /dev/vdb
+ Creating disk 1: /dev/vdc
! Starting virtual machine
! Adding disk 0: /dev/vdb
! Adding disk 1: /dev/vdc
! Waiting virtual machine network to be up
! Checking if disk is online:
* Found 0 extra disks online
$ Missing disk(s) exiting

#
# Precise latest kernel 
#
# CONFIG_HOTPLUG_PCI=y
# CONFIG_HOTPLUG_PCI_FAKE=m
# CONFIG_HOTPLUG_PCI_ACPI=y
#

inaddy@sf00068947precise:~$ uname -a
Linux sf00068947precise 3.2.69-inaddy #1 SMP Wed Aug 12 15:43:37 BRT 2015 x86_64 x86_64 x86_64 GNU/Linux

inaddy@alien:teste$ ./teste.sh
% RUN: 1
+ Creating disk 0: /dev/vdb
+ Creating disk 1: /dev/vdc
! Starting virtual machine
! Adding disk 0: /dev/vdb
! Adding disk 1: /dev/vdc
! Waiting virtual machine network to be up
! Checking if disk is online:
* Found 2 extra disks online
! Destroying virtual machine
...
...
% RUN: 16
+ Creating disk 0: /dev/vdb
+ Creating disk 1: /dev/vdc
! Starting virtual machine
! Adding disk 0: /dev/vdb
! Adding disk 1: /dev/vdc
! Waiting virtual machine network to be up
! Checking if disk is online:
* Found 2 extra disks online
! Destroying virtual machine
...

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1479031

Title:
  attached block devices not showing up

Status in linux package in Ubuntu:
  Fix Released
Status in linux source package in Precise:
  In Progress

Bug description:
  I have Ubuntu Precise guests running in kvm to which I attach volumes
  immediately after boot. Sometimes I notice that the devices do not
  show up in the guest e.g. they are not visible in /proc/partitions and
  dmesg boot log shows no sign of then being noticed. Qemu itself shows
  that the devices are attached and if I do a rescan within the guest
  the devices appear. A reboot also cause the devices to appear. So, it
  feels like there is enough evidence to suggest that the devices were
  properly attached by qemu/seabios but they just didn't get noticed by
  the guest.

  This issue is reproducible with Precise running 3.2, 3.5 (lts-quantal)
  and 3.8 (lts-raring) kernels but not as of 3.11 (lts-saucy) so it
  would appear that something changed between 3.8 and 3.11 that resolved
  this issue and if we can identify it we should backport to 3.2.

  I am able to reproduce this issue using Openstack to spin up vms and
  attach volumes using the following script:

  http://pastebin.ubuntu.com/11954253/

  I hit this issue with 1/2 instances.

  As a workaround one can rescan and the device shows up:
  echo 1 | sudo tee /sys/bus/pci/rescan

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