Test Day:2009-09-17 Virtualization qcow2

What to test?
This part of today's Fedora Test Day will focus on testing,   and   support for the qcow2 image format.

This is related to the KVM qcow2 Performance feature in Fedora 12. If we're to advertise the format's improved performance, we better test that people can use the format!

If you come to this page after the test day is completed, your testing is still valuable, and you can use the information on this page to test qcow2 support and provide feedback.

Who's available
Cole Robinson and Kevin Wolf (IRC nick kwolf, GMT+2h) are your hosts for today.

The following people have also agreed to be available for testing, workarounds, bug fixes, and general discussion:


 * add your name here

What's needed to test

 * A fully updated Fedora 12 Rawhide machine. See instructions on the main test day page.
 * At least one guest image installed before the test day (suggested reading - Virtualization_Quick_Start)

Advanced aspects
If you want to play a bit more with qcow2 and the test cases suggested above are not enough for you, there are some additional features that cannot be accessed with the management tools (so they are not top priority to be tested), but you still can use them by invoking qemu-img and qemu manually.

When creating images with qemu-img, you can change some default options using the -o parameter. For example you could create a fairly non-standard image using. To get an overview of the supported options, you can use.

The following list contains some suggestions on what you could test:
 * Encrypted images
 * Varying cluster sizes ( where size is between 512 and 64k). Smaller cluster can save some space on almost empty disks, larger clusters are faster usually.
 * Backing files . The new image is based on the given backing file and only differences are saved into the qcow2 file. Try usinh different formats for the backing file, it doesn't need to be qcow2.
 * Commit back the changes from a qcow2 image to its backing file ( or the   command in the qemu monitor)
 * Snapshots: You can either snapshot the disk of a turned off VM or use the qemu monitor to save the state of a running VM . In the former case, you can revert the disk to the saved state using  . Using the qemu monitor  you restore the complete VM state as it was when you saved the snapshot. Alternatively, you can also use the -loadvm option on the qemu command line to start a VM using a previously saved snapshot.
 * Compressed images: When converting an image, you can have the resulting qcow2 image compressed
 * Combine things: Snapshots on an encrypted image with a compressed backing file...

If you suspect that something has gone wrong with your image and you want to check it, you can try.

Issues that were identified
{| border="1"
 * -style="color: white; background-color: #3074c2; font-weight: bold"
 * Tester || Description || Bug references || Status
 * phan || VM cannot boot from the disk converted by qemu-img || #523948 || NEEDINFO
 * jbao || VM cannot boot from the backing disk img || #525362 || NEEDINFO
 * jbao || VM cannot boot from the backing disk img || #525362 || NEEDINFO
 * jbao || VM cannot boot from the backing disk img || #525362 || NEEDINFO