UCS 2.4 - Univention

10 Basic System Services
• A list of the current Samba connections (smbstatus)
The runtimes in which the system status should be logged can be defined in Cron syntax via the Univention
Configuration Registry variable system/stats/cron, e.g., 0,30 * * * * for logging every half and full hour.
The logging is activated by setting the Univention Configuration Registry variable system/stats to yes.
10.7 Kernel
10.7.1 Available kernel variants
Several kernel variants are provided in UCS in order to be able to adapt systems efficiently to the require-
ments of different environments.
The standard kernel in UCS 2.4 is based on the official Linux kernel 2.6.30. In principle, there are three
different types of kernel packages:
• A kernel image package provides an executable kernel which can be installed and started.
• A kernel source package provides the source code for a kernel. From this source, a tailor-made
kernel can be created, and functions can be activated or deactivated.
• A kernel header package provides interface information which is required by external packages if
these have to access kernel functions. This information is usually necessary for compiling external
kernel drivers.
Normally, the operation of a UCS system only requires the installation of one kernel image package.
The standard kernel in UCS for i386-based systems supports 64 GB RAM in installations as of Version 2.4
(the so-called bigmem kernel for processors with PAE support). The standard kernel for amd64 systems
directly supports more than 4 GB working memory, which renders a 64 GB version for amd64 systems
unnecessary.
Several kernel versions can be installed in parallel. This makes sure that there is always an older version
available to which can be reverted in case of an error. So-called meta packages are available which always
refer to the kernel version currently recommended by UCS. In case of an update, the new kernel version
will be installed, making it possible to keep the system up to date at any time.
A full list of all meta packages can be found in the Univention Wiki:
http://wiki.univention.de/index.php?title=Supported_kernel_variants
10.7.2 Hardware drivers / kernel modules
Unlike other operating systems, the Linux kernel (with very few exceptions) provides all drivers for hardware
components from one source. For this reason, it is not normally necessary to install drivers from external
sources subsequently.
The boot process occurs in two steps using an initial ramdisk (’initrd’ for short). This is composed of an
archive with further drivers and programs.
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