User`s guide

Virtualization

• Automatic Path Migration (APM)

• Active Bonding (AB)

• Shared Request Queue (SRQ)

• Netfilter (NF)

• Support for IB, OFED, and RDS is integrated into the kernel. The OFED user-space RPMs continue to

be provided, but the kernel-ib and ofa-kernel RPMs are not required.

• A new iSCSI implementation raises the supported iSCSI target framework to LIO version 4.1. (3.1)

1.1.14 Virtualization

• Paravirtualization support has been enabled for Oracle Linux guests on Windows Server 2008 Hyper-V

or Windows Server 2008 R2 Hyper-V.

• VFS scalability improvements:

• The inode_sta.nr_unused counter has been converted to a per-CPU counter.

• The global LRU list of unused inodes has been converted to a per-superblock LRU list.

• The ipruce_sem semaphore has been removed because of changes to the LRU lists.

• The i_alloc_sem functionality has been replaced with a simplified scheme.

• The scalability of mount locks has been improved for file systems that do not have mount points.

• The use of inode_hash_lock is avoided for pipes and sockets.

(3.1)

• privcmd is a new character device driver that handles access to arbitrary hypercalls through XenFS.

(3.3)

• xenbus_backend is a new device driver for xenbus used by XenFS. (3.3)

• The xenbus device driver adds a new character device featuring nmap for the pre-allocated ring and an

ioctl() for the event channel via XenFS. (3.3)

• The Virtual Extensible LAN (VXLAN) tunneling protocol overlays a virtual network on an existing Layer

3 infrastructure to allow the transfer of Layer 2 Ethernet packets over UDP. This feature is intended for

use by a virtual network infrastructure in a virtualized environment. Use cases include virtual machine

migration and software-defined networking (SDN). (3.7)

1.2 Xen Improvements

Relative to Unbreakable Enterprise Kernel Release 2 Quarterly Update 4, numerous bug fixes and

performance improvements have been incorporated into the Unbreakable Enterprise Kernel to support Xen

usage, including:

• Fixes for EDD, x2apic, XenBus, and PVHVM vCPU hotplug issues.

• The indirect-descriptor feature, which increases throughput and reduces latency for block I/O.