Bug 722938

Summary: Incorrectly hardcode io=threads (which is the qemu default). should use io=native for block based disks
Product: Red Hat Enterprise Linux 6 Reporter: Cole Robinson <crobinso>
Component: python-virtinstAssignee: Cole Robinson <crobinso>
Status: CLOSED ERRATA QA Contact: Virtualization Bugs <virt-bugs>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 6.2CC: mjenner, nzhang, zpeng
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
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Fixed In Version: Doc Type: Bug Fix
Doc Text:
No description necessary
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Clone Of: Environment:
Last Closed: 2011-12-06 16:16:57 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Cole Robinson 2011-07-18 14:38:41 UTC
We have a RHEL6 only patch which encodes io=threads for all disk devices. This is unneeded since that is actually the qemu default.

What we should be doing is setting io=native for hard disks backed by a block device, which is the more performant option.

Comment 2 Cole Robinson 2011-07-21 21:48:41 UTC
Defaults are tracked upstream now with a --rhel6defaults build time switch:

http://git.fedorahosted.org/git?p=python-virtinst.git;a=commit;h=0075dd8730adaf8aa3d7f90655d0626374fdd5b4

Just need to turn that on when we rebase

Comment 3 Cole Robinson 2011-07-28 15:34:41 UTC
Fixed in python-virtinst-0.600.0-1.el6

Comment 6 zhe peng 2011-08-03 08:35:15 UTC
Verify with:
python-virtinst-0.600.0-2.el6
qemu-kvm-0.12.1.2-2.172.el6
libvirt-0.9.4-0rc2.el6


step :
 run command line to install a guest with block device:
# virt-install -n demo2 -r 1024 --disk path=/var/lib/libvirt/images/demo2.img,size=6 --disk path=/dev/sda2 -c /tmp/RHEL6.1-20110510.1-Server-x86_64-DVD1.iso --vnc
#virsh dumpxml demo2
......
  <disk type='file' device='disk'>
      <driver name='qemu' type='raw' cache='none'/>
      <source file='/var/lib/libvirt/images/demo2.img'/>
      <target dev='hda' bus='ide'/>
      <alias name='ide0-0-0'/>
      <address type='drive' controller='0' bus='0' unit='0'/>
    </disk>
    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none' io='native'/>
      <source dev='/dev/sda2'/>
      <target dev='hdb' bus='ide'/>
      <alias name='ide0-0-1'/>
      <address type='drive' controller='0' bus='0' unit='1'/>
    </disk>
......
#ps -ef | grep demo2qemu     28626     1  7 04:29 ?        00:00:06 /usr/libexec/qemu-kvm -S -M rhel6.2.0 -enable-kvm -m 1024 -smp 1,sockets=1,cores=1,threads=1 -name demo2 -uuid 3c5f785e-2cba-cb49-10a6-85ccc39ab524 -nodefconfig -nodefaults -chardev socket,id=charmonitor,path=/var/lib/libvirt/qemu/demo2.monitor,server,nowait -mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc -no-reboot -no-shutdown -drive file=/var/lib/libvirt/images/demo2.img,if=none,id=drive-ide0-0-0,format=raw,cache=none -device ide-drive,bus=ide.0,unit=0,drive=drive-ide0-0-0,id=ide0-0-0,bootindex=2 -drive file=/dev/sda2,if=none,id=drive-ide0-0-1,format=raw,cache=none,aio=native -device ide-drive,bus=ide.0,unit=1,drive=drive-ide0-0-1,id=ide0-0-1 -drive file=/tmp/RHEL6.1-20110510.1-Server-x86_64-DVD1.iso,if=none,media=cdrom,id=drive-ide0-1-0,readonly=on,format=raw -device ide-drive,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0,bootindex=1 -netdev tap,fd=33,id=hostnet0 -device rtl8139,netdev=hostnet0,id=net0,mac=52:54:00:cf:65:4e,bus=pci.0,addr=0x3 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -usb -vnc 127.0.0.1:3 -vga cirrus -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x4

verification passed.

Comment 7 Cole Robinson 2011-11-07 16:53:52 UTC
    Technical note added. If any revisions are required, please edit the "Technical Notes" field
    accordingly. All revisions will be proofread by the Engineering Content Services team.
    
    New Contents:
No description necessary

Comment 8 errata-xmlrpc 2011-12-06 16:16:57 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2011-1643.html