RHEA-2018:3478 - Product Enhancement Advisory

Topic

Updated vdsm packages that fix several bugs and add various enhancements are now available.

Description

VDSM is a management module that serves as a Red Hat Virtualization Manager agent on Red Hat Virtualization Host or Red Hat Enterprise Linux hosts.

Changes to the vdsm component:

• In certain cases, when a VM does not successfully complete migration to its destination host, it still boots and runs on the destination host, without VDSM managing it properly. This unmanaged VM can cause split-brain. With this release, a migrating VM is always prevented from starting if the VM setup fails on the destination host. (BZ#1627289)
• Large snapshots can result in long pauses of a VM that can affect the accuracy of the System Time, upon which time stamps and other time related functions depend. Guest Time Synchronization enables synchronization of the VM’s System Time during the creation of snapshots when enabled. When this feature is enabled and the Guest Agent is running, the VDSM process on the Host attempts to synchronize the System Time of the VM with the Host’s System Time when snapshots are completed and the VM is un-paused. To turn on Guest Time Synchronization for snapshots, use the time_sync_snapshot_enable option. For synchronizing the VM’s System Time during abnormal scenarios that may cause the VM to pause, you can enable the time_sync_cont_enable option. By default, these features are disabled for backward compatibility. (BZ#1620573)
• Copying volumes to preallocated disks is slower than it can be, and does not make optimal use of available network resources. In this release, qemu-img uses out of order writing. As a result, write operations, such as importing, moving or copying large disks to preallocated storage, can be up to 6 times faster. (BZ#1621211)
• When a VM is running, the disk size of the virtual machine should be no larger than was required during the initial allocation of disk space, unless you specify pre-allocation. Previously, when you set thin provisioning for importing a KVM-based VM into a Red Hat Virtualizaton environment, the disk size of the VM within the Red Hat Virtualization storage domain was inflated to the volume size or larger, even when the original KVM-based VM was much smaller.

KVM Sparseness is now supported so that when you import a virtual machine with thin provisioning enabled into a Red Hat Virtualization environment, the disk size of the original virtual machine image is preserved. (BZ#1628477)

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

For details on how to apply this update, refer to:

https://access.redhat.com/articles/2974891

Affected Products

• Red Hat Virtualization 4 for RHEL 7 x86_64
• Red Hat Virtualization for IBM Power LE 4 for RHEL 7 ppc64le

Fixes

• BZ - 1620573 - [downstream clone - 4.2.7] [RFE] Time sync in VM after resuming from PAUSE state
• BZ - 1621211 - [downstream clone - 4.2.7] qemu-img: slow disk move/clone/import
• BZ - 1627289 - [downstream clone - 4.2.7] startUnderlyingVm fails with exception resulting in split-brain
• BZ - 1628477 - [downstream clone - 4.2.7] After importing KVM VM the actual size is bigger than the virtual size
• BZ - 1635687 - [downstream clone - 4.2.7] Guest agent info is not reported with latest vdsm

CVEs

(none)

References

(none)