Installation guide

DEVICE=eth0
BOOTPROTO=static
HWADDR=00:06:29:FB:5F:F1
IPADDR=9.12.20.136
NETMASK=255.255.255.0
ONBOOT=yes
NETTYPE=qeth
SUBCHANNELS=0.0.09a0,0.0.09a1,0.0.09a2
TYPE=Ethernet
Based on the type interface being added, the DEVICE parameter should be like one of the
following:
DEVICE=hsin
DEVICE=ethn
DEVICE=trn
Activate the device.
Based on the type interface being added, issue an ifup command:
# ifup hsin
# ifup ethn
# ifup trn
22.7. Kernel-Relat ed Informat ion
Red Hat Enterprise Linux includes a modification to the way the Linux kernel timer interrupt is
handled. Normally, a hardware timer is set to generate periodic interrupts at a fixed rate (100 times a
second for most architectures). These periodic timer interrupts are used by the kernel to schedule
various internal housekeeping tasks, such as process scheduling, accounting, and maintaining
system uptime.
While a timer-based approach works well for a system environment where only one copy of the kernel
is running, it can cause additional overhead when many copies of the kernel are running on a single
system (for example, as z/VM(R) guests). In these cases, having thousands of copies of the kernel
each generating interrupts many times a second can result in excessive system overhead.
Therefore, Red Hat Enterprise Linux now includes the ability to turn off periodic timer interrupts. This
is done through the /proc/ file system. To disable periodic timer interrupts, issue the following
command:
echo 0 > /proc/sys/kernel/hz_timer
To enable periodic timer interrupts, issue the following command:
echo 1 > /proc/sys/kernel/hz_timer
By default, periodic timer interrupts are disabled.
Periodic timer interrupt states can also be set at boot-time; to do so, add the following line to
/etc/sysctl.conf to disable periodic timer interrupts:
kernel.hz_timer = 0
⁠Chapt er 2 2 . Addit ional Informat ion for IBM Syst em z Users
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