[Bug 1189926] [NEW] data corruption in storage attached to VM using KVM

[Launchpad Bug Tracker]

You have been subscribed to a public bug by Chris J Arges (arges):

[Impact]

When using qemu-kvm-1.0 occasionally qcow2 disks will be corrupted.

[Test Case]

A test case can be downloaded here:
    http://people.canonical.com/~arges/lp1189926/lnv-382.tgz
Extract the contents and run ./create-disk, then ./test-kvm to test the currently installed KVM. Keep in mind that 100GB+ of disk is required to run the test.

[Regression Potential]

The patch is a backport of commit
143550a83ef4eef86a847d00023d148e1f59f743 upstream, which changes the way
that the number of available clusters are counted. While the original
patch has assumptions that certain functions are available, the backport
had to change these to be able to apply to v1.0.

--

When using io_perf corruption can be detected when using qemu-kvm-1.0.
A test case can be downloaded here:
    http://people.canonical.com/~arges/lp1189926/lnv-382.tgz
Extract the contents and run ./create-disk, then ./test-kvm to test the currently installed KVM. Keep in mind that 100GB+ of disk is required to run the test.

This affects the qemu-kvm version in Precise, but is fixed in Quantal
and beyond.

It is expected that running the test case results in no disk corruption;
however we detect corruption on Precise.

Running git bisect on this test finds that commit 68d100e905453ebbeea8e915f4f18a2bd4339fe8 introduced the problem between v0.15.0 and v1.0.
Running git bisect in reverse finds that commit b7ab0fea37c15ca9e249c42c46f5c48fd1a0943c fixes the issue between v1.1.2 and v1.2.0.

However, b7ab0fea cannot be easily backported to v1.0 and 68d100e9 is a
large change to revert. However, both changes seem to indicate that the
problem lies in the qcow2 parts of the code.

bug 1040033 seems to be a related issue.

** Affects: qemu-kvm (Ubuntu)
     Importance: Undecided
         Status: Fix Released

** Affects: qemu-kvm (Ubuntu Precise)
     Importance: High
     Assignee: Chris J Arges (arges)
         Status: In Progress

** Affects: qemu-kvm (Ubuntu Quantal)
     Importance: High
         Status: Fix Released

-- 
data corruption in storage attached to VM using KVM
https://bugs.launchpad.net/bugs/1189926
You received this bug notification because you are a member of Ubuntu Sponsors Team, which is subscribed to the bug report.