/contrib/famzah

Enthusiasm never stops

Tag Archives: kvm


by Leave a comment

Changing the ISO image in a virtual CDROM drive while KVM-Qemu is running

If you run KVM with enabled monitor management console, you can do some pretty powerful internal stuff while the KVM guest is running.

In order to have a KVM-Qemu management console, you should start KVM with something like:

-monitor telnet:127.0.0.1:3010,server,nowait,ipv4

See the official documentation of Qemu for more details and also the man page of qemu-kvm (unofficial mirror).

Once you have it set up, you can then telnet to the management console and review the available commands:

famzah@famzahpc:~$ telnet localhost 3010
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

QEMU 0.11.0 monitor - type 'help' for more information
(qemu) help

Changing the ISO image of a virtual CDROM drive is quite easy:

  • First review what the current status of the drives is: 
    (qemu) info block
virtio0: type=hd removable=0 file=/dev/sdb-vol/win7 ro=0 drv=host_device encrypted=0
ide0-cd0: type=cdrom removable=1 locked=0 file=/shared/win7-eval.iso ro=0 drv=raw encrypted=0
ide1-cd0: type=cdrom removable=1 locked=0 [not inserted]
  • Then change the mounted ISO image in the CDROM drive on the fly: 
    (qemu) change ide1-cd0 /shared/win-virtio-drivers.iso
  • Double-check that the changes took effect. KVM-Qemu will not issue an error message in case something went wrong (duh!): 
    (qemu) info block
virtio0: type=hd removable=0 file=/dev/sdb-vol/win7 ro=0 drv=host_device encrypted=0
ide0-cd0: type=cdrom removable=1 locked=0 file=/shared/win7-eval.iso ro=0 drv=raw encrypted=0
ide1-cd0: type=cdrom removable=1 locked=0 file=/shared/win-virtio-drivers.iso ro=1 drv=raw encrypted=0

Use the “help” command to review the other powerful commands which you can use to tune and debug your running KVM guest (“info”, “migrate” and “system_reset” seem like interesting candidates).


by 11 Comments

KVM-Qemu Virtio storage and network drivers for 32-bit/64-bit Windows 7, Windows Vista, Windows XP and Windows 2000

…bundled as ISO images, so that you can easily mount and use them in a KVM guest.

UPDATE: It seems that Fedora started to provide the latest drivers bundled as an ISO. Check the official Windows VirtIO Drivers page for links.

Download locations follow:

These are static ISO images, and I’ve built them by downloading the ZIP sources dated 24.09.2009 from the official WindowsGuestDrivers KVM page and then converting them to ISO image files by using K3b.

Note that Virtio provides noticeably faster disk and network access.

Please review the official page of Virtio for sample KVM command line arguments which set up Virtio storage and network devices. You may notice that there is an (undocumented) parameter “boot=on” specified for the “-drive” option. This “boot=on” parameter is vital for the “-drive” option, or else Windows 7 won’t like your drive and won’t install on it.

Note about Virtio storage drives and the Windows 7 installer
I was able to install Windows 7 right from the start by using a Virtio storage drive within the KVM guest. At first the Windows installer didn’t see the Virtio disk at all but there is an option to install additional storage drivers. I installed the Virtio Windows drivers from the above ISO images, the Windows installer detected the Virtio storage disk properly and everything went quite smooth afterwards.

Resources: