Linux Kernel Roadmap for Ubuntu LTS

Since we are mostly a Ubuntu Shop we are somewhat interested which Kernel will be in the next version 14.04 LTS. Since there is no official road map we have to do a little crystal balling. Let's see how long each release actually takes in the 3.x series. Taking the release dates from Wikipedia we see an average on 67 days in the last 2 years:

Version      Release Date           Days

3.0    7/22/2011    64

3.1   10/24/2011    94

3.2    1/05/2012    73

3.3    3/19/2012    74

3.4    5/21/2012    63

3.5    7/12/2012    52

3.6   10/01/2012    81

3.7   12/11/2012    71

3.8    2/19/2013    70

3.9    4/29/2013    69

3.10   6/30/2013    62

3.11   9/02/2013    64

and assuming that Linus will turn into a robot and releases every 67 days the future may look like this:

3.12   11/8/2013    67

3.13   1/14/2014    67

3.14   3/22/2014    67

3.15   5/28/2014    67

3.16    8/3/2014    67

3.17   10/9/2014    67

3.18   2/15/2014    67

3.19   2/20/2015    67

3.20   4/28/2015    67

3.21    7/4/2015    67

3.22    9/9/2015    67

3.23  11/15/2015    67

3.24   1/21/2016    67

3.25   3/28/2016    67

For Ubuntu 14.04 this means that the Kernel will either be 3.13 or 3.14, the former is perhaps more likely.

"ZFS on Linux" ready for wide scale deployment

Quoting lead developer Brian Behlendorf from Lawrence Livermore National Lab (LLNL):

"Today the ZFS on Linux project reached an important milestone with the official 0.6.1 release! Over two years of use by real users has convinced us ZoL is ready for wide scale deployment on everything from desktops to super computers." Read the full announcement

ZFSOnLinux (or ZoL) is a high performance implementation of ZFS as a Kernel module and performance is on par with Solaris (especially on new Hardware).

It is used by the LLNL Sequoia HPC Cluster with 55PB of storage:

http://arstechnica.com/information-technology/2012/06/with-16-petaflops-and-1-6m-cores-doe-supercomputer-is-worlds-fastest/

The porting of ZFS to Linux has been funded by DOE and did start in 2008. Is it important to understand that ZoL is not currently an unstable beta but the result of a more than 5 year effort.

Please see presentations from 2011 and 2012 that provide additional details:
http://zfsonlinux.org/docs.html

Ubuntu 12.04.2 LTS Kernel confusion

Recently there were some changes in Ubuntu:With the release of 12.04.2 it seems new installs from cd/dvd will use the lts-quantal kernel 3.5 from Ubuntu 12.10 by default..... however apt-get upgrade and dist-upgrade will continue to default to the old 3.2 kernel. The 3.5 kernel will enjoy the same support the 3.2 kernel had, but the 3.5 kernel will only be supported until the next LTS release 14.04 while the 3.2 kernel will be supported for the full 5 years. Canonical recommends to leave VMs and cloud installs at 3.2.
https://wiki.kubuntu.org/Kernel/LTSEnablementStack
Since we want to keep our Scientific Computing stack fresh this would mean that we upgrade to 14.04 next year. This puts one question on the table: Do we want to upgrade our current compute systems to kernel 3.5 or stay on 3.2?
Not yet sure if there are any direct benefits other than better support for the Micron SSD controller in the Dell R720 hardware we use. One that I could see is that it supports tcp connection repair which is useful for HPC checkpointing.
Another interesting feature is improved performance debugging.
http://kernelnewbies.org/Linux_3.5#head-95fccbb746226f6b9dfa4d1a48801f63e11688de
and a network priority cgroup:
http://kernelnewbies.org/Linux_3.3#head-f0a57845639c0fbc242438e4cb76d44d1f103c24
we would probably leave most of our virtual systems on kernel 3.2 to enjoy the full 5 year support, our desktop deployment should may be go to 3.5 if the hardware requires it.