最後更新: 2023-11-17

Ubuntu Server Pro

Pro: Main + Universe: 10 years
LTS: 5 years

Mirror

Get list of mirror

wget -qO- mirrors.ubuntu.com/mirrors.txt

改用指定 mirror

sed -i 's/archive.ubuntu.com/mirror.xtom.com.hk/g' /etc/apt/sources.list

Backports

/etc/apt/sources.list

14.04

deb http://archive.ubuntu.com/ubuntu trusty-backports main restricted universe multiverse

12.04

deb mirror://mirrors.ubuntu.com/mirrors.txt precise-backports main restricted universe

# Configuring Backports for Manual Install

/etc/apt/preferences

Package: *
Pin: release a=precise-backports
Pin-Priority: 100

Install backport package

apt-get install btrfs-tools/precise-backports

E: Release 'precise-backports' for 'btrfs-tools' was not found

Kernel Difference

常見的 Kernel Package 有

meta package

• linux-image-server package is a meta package that will install the latest Server kernel version
• linux-image-generic package is a meta package for the latest Desktop kernel version

特別 package

• linux-image-3.2.0-54-virtual                  # For VM 用
• linux-image-3.2.0-41-lowlatency

在 12.04 已沒有分 server 與 generic 了

原因:

an effort to reduce the maintenance burden over the life of the LTS

image-server 與 image-generic 的不同

• default I/O scheduler
• preemption model.

The virtual kernel

It only includes the necessary drivers to run inside popular virtualization technologies such as KVM, Xen, and VMWare.

The lowlatency kernel

Ubuntu Studio 是用它的

linux-lowlatency is based on the Ubuntu linux-generic kernel.

It has a few differing configurations to allow for more aggressive preempting.

https://wiki.ubuntu.com/RealTime

linux-lowlatency is being able to achieve software processing with latencies well below the human perception threshold of 5 to 10 ms.

The scheduler allows applications to request immediate CPU time, which can drastically reduce audio latency.