Bug 688604 - qemu-kvm: Add virtio disk identification support
Summary: qemu-kvm: Add virtio disk identification support
Keywords:
Status: CLOSED DUPLICATE of bug 710349
Alias: None
Product: Red Hat Enterprise Linux 6
Classification: Red Hat
Component: qemu-kvm
Version: 6.2
Hardware: All
OS: Linux
medium
medium
Target Milestone: rc
: ---
Assignee: Virtualization Maintenance
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On:
Blocks: 687042
TreeView+ depends on / blocked
 
Reported: 2011-03-17 13:33 UTC by Vivek Goyal
Modified: 2013-01-09 23:40 UTC (History)
7 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2011-06-09 20:10:32 UTC
Target Upstream Version:


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Description Vivek Goyal 2011-03-17 13:33:07 UTC
Description of problem:

Add virtio disk identification support in rhel6 qemu-kvm. I noticed same is present in upstream qemu-kvm.

Commit 2930b313dd602d67a568815b0b031b824916cec9
Author: john cooper <john.cooper>
Date:   Fri Jul 2 13:44:25 2010 -0400

     Add virtio disk identification support

In kdump we need to make sure that we are dumping to right device and due to device renaming issues we don't end up dumping to wrong device. Hence we are planning to read /sys/block/<virtio-device>/serial and store in kdump-initrd
and re-read it again in kdump kernel and match serial numbers before we proceed with saving vmcore.

Current plan is to read /sys directly. Is there a use space tool which can
do the job of getting the serial number?


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Comment 1 Vivek Goyal 2011-03-17 13:36:02 UTC
I have opened a kernel size bz 687042 for tracking the kernel virtio-blk changes to export device serial through /sys.

Comment 4 Vivek Goyal 2011-03-18 13:30:31 UTC
- i think you can try running lsscsi and see if device appears there or not.
- Or parse the device name. I am assuming that all virtio block devices are
  going to start with "v".
- Or if scsi_id does not report the device identity, then try to read serial
  number.

Comment 5 Vivek Goyal 2011-03-18 13:44:32 UTC
for virtio devices, udevadm is reporting following path info.

[root@rhel6-vm1 ~]# udevadm info --query=all --name=/dev/vdb
P: /devices/pci0000:00/0000:00:07.0/virtio3/block/vdb


I think you can grep for virtio keyword for recognzing virtio devices.

Comment 6 Vivek Goyal 2011-03-18 13:46:07 UTC
I think it is boiling down to trial and error thing. We can also probably look into udev and try to figure out what they are doing to identify different kind
of devices.

In long run, we really need udev in second kernel so that all this device identification logic is handled by udev and we don't end up duplicating it in
kexec-tools.

Comment 7 Cong Wang 2011-03-21 03:49:07 UTC
IIRC, the reason why we don't include udev is that it can cause OOM easily. Don't know how much mdev can do to replace udev...

Comment 9 Don Dutile (Red Hat) 2011-06-09 20:10:32 UTC
Closing as dupe of 710349, patch posted to rhel6.2 by Amit Shah

*** This bug has been marked as a duplicate of bug 710349 ***


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