How to update/check the ubuntu kernel configuration? - linux

I am new to Linux, and currently I want to try Kubernetes in my laptop. The official tutorial says
You need to have docker installed on one machine.
Your kernel should support memory and swap accounting. Ensure that the following configs are turned on in your linux kernel:
CONFIG_RESOURCE_COUNTERS=y
CONFIG_MEMCG=y
CONFIG_MEMCG_SWAP=y
CONFIG_MEMCG_SWAP_ENABLED=y
CONFIG_MEMCG_KMEM=y
I just installed Ubuntu 14.04, and I dont know whether the above configs are already turned on or not, how to check them? and if some are still off, how to turn them on?

Related

Are there any limitations regarding the age of a linux distribution which can be used to create a docker base-image?

Im wondering if its possible to use very old Linux Distribution like Debian GNU/Linux 3.1 (Sarge) and create a base-image of it to run legacy code not working under "younger" distros.
Only Thing i found about it was somebody successfully using Ubuntu Feisty: Run old Linux release in a Docker container?
Are there any known limitations?
Your host needs to have a minimal version of the Linux kernel, and that version is 3.10
See
Docker minimum kernel version 3.8.13 or 3.10
extract from the previous link
There's also a shell-script to check if your system has the required dependencies in place and to check which features are available;
https://github.com/docker/docker/blob/master/contrib/check-config.sh
So you can use this to check if you will be able to use docker on this host.
From
https://wiki.debian.org/DebianSarge?action=show&redirect=Sarge
I see
kernel : linux 2.4.27 and 2.6.8
So it may not work

Centos/RHEL 7 XEN paravirtualized DomU stoped booting

After a recent kernel update for Centos 7.4, Paravirtualized DomUs under Xen stooped booting. They just crash on boot.
Apparently it seems a new restriction in RHEL 7 kernel. And there are some suggestions i found in different forums to switch to HVM or PVHM. Problem is that most of Paravirt DomUs are installed on plain disks (without partitions). But to convert them to HVM or PVHM they need Grub installed inside the VM which need partition table. So it is a full reinstallation :(
Centos guys say it is something RHEL need to fix. So is this a bug which can be fixed in near future ? or is that RHEL just dont want its kernel to run on Paravirt vms any more ?
Had the same issue, and as a hack workaround installed the CentOS Xen kernel before upgrading to 7.4. Had no issues booting with that kernel in place. If RedHat fixes their kernel it should be relatively simple to switch back to it.

Oracle on lxc in ubuntu

I'm currently trying to install an oracle server (11g) in a linux container on ubuntu (following this tutorial (http://www2.hawaii.edu/~lipyeow/ics321/2014fall/installoracle11g.html).
When I try to change the file handler with sysctl, the modifications doesn't save into my container. Moreover, when I make the modification in the main ubuntu kernel, it propagates to the containers, so my question is as follow:
How can I modify the file handlers only in my oracle container ?
Thanks.
Try out the Orabuntu-LXC project code. It supports Ubuntu 16.04, 17.04, 17.10 and is purpose-built for running Any Oracle on Any Linux, including Ubuntu Linux. Note that as you probably already know, Oracle Corp does not formally support or certify Oracle on Ubuntu Linux.
As far as you question about the file handlers, some sysctl values can only be set at the LXC host level, and some can be set in the container.
https://sites.google.com/site/nandydandyoracle/oracle-rac-in-lxc-linux-containers/oracle-lxc-vlc#TOC-Install-the-etc-sysctl.conf-File-Required-for-Oracle
https://github.com/gstanden/orabuntu-lxc
https://sites.google.com/site/nandydandyoracle/
Please note that the step-by-step guides are quite old and that the basic LXC infrastructure together with OpenvSwitch, an LXC-containerized DNS/DHCP, and an optional SCST Linux SAN can all be installed on Ubuntu 16.04, 17.04 and 17.10 with one command:
./anylinux-services.sh
after completion of which all you would need do is download your Oracle database installtion media and install.

Installing another version of linux on my system

I need to build locally a driver for "precise" Ubuntu edition (uname -r for that system returns 3.2.0-33-generic-pae).
My local host is Ubuntu 13.10 'sausy'.
But I fail to install the linux headers( what should I do to set up the environment I need?)
I downloaded the image from here: from packages.ubuntu but what my next steps should be?
Actually I don't need exact steps but pointing the right direction would be great!
Thanks in advance :)
If you want to just build the driver (with out installing/testing)
then you will just have to download the kernel source of the preferred version (in this case it is 3.2.0-33) from kernel.org, build it with config from your host PC, and then compile your driver/module against that.
If you plan to install/test then after building the kernel source of the preferred version,
install the same to your host PC, then you will be able to insmod the driver you built

Update linux kernel to > 3.15-rc5 and still use CentOS 6.5

I am running CentOS 6.5 on top of Linux kernel 2.6.32-358.6.1.el6.x86_64
I got a warning from my vserver hoster that I need to upgrade to a Linux kernel > 3.15-rc5 because there is a security breach that would allow my server to be taken over.
I did a yumupgrade, but it wouldn't upgrade the kernel to a higher version than 2.6.32-358.6.1.el6.x86_64.
Currently I am confused about how to go on.
Could anybody tell me what is going on and how he would act in my position?
Thank you!
That kernel is a development kernel and will likely require you compile from source to install it. Upgrading from kernel 2.6 to 3.1n will likely break a bunch of packages also. The upgrade path for 3.1n in CentOS would be to upgrade to CentOS7 and then compile that kernel yourself.
CentOS backports security fixes and I certainly haven't heard anything about any security bug, and we manage like 150 centos servers. I would ask your host to specify what the security bug is and which patch applied in the 3.15-rc5 kernel fixes it. Who's the host?
I'm using CentOS 6.5 and have no problem using the ElRepo Long term kernel (currently 3.10.x).
See http://elrepo.org/tiki/kernel-lt
Upgrading was just a case of
yum --enablerepo=elrepo-kernel install kernel-lt
and rebooting.

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