Using udev to simplify HP Serviceguard for Linux configuration, March 2014

ManualsBrandsHP ManualsSoftwareHP Serviceguard for Linux License Kit

Technical white paper

Using udev to simplify

HP Serviceguard for

Linux configuration

Table of contents

Introduction .................................................................................................................................................................................... 2

Audience .......................................................................................................................................................................................... 2

Naming considerations ................................................................................................................................................................ 2

CCISS ............................................................................................................................................................................................ 3

Naming for mirror halves of an MD device .............................................................................................................................. 3

Configuring udev ........................................................................................................................................................................... 3

Writing rules for a device ......................................................................................................................................................... 3

Creating links for persistence ................................................................................................................................................. 5

Conclusion ....................................................................................................................................................................................... 6

Summary of content (6 pages)

PAGE 1
Technical white paper Using udev to simplify HP Serviceguard for Linux configuration Table of contents Introduction .................................................................................................................................................................................... 2 Audience ..........................................................................................................................................................................................
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Technical white paper | Using udev to simplify HP Serviceguard for Linux configuration Introduction Device names are generally assigned by Linux at boot time. Using these device names in scripts or other applications can cause problems as configurations change over time. HP Serviceguard for Linux requires the use of device names in user modified scripts and for LockLUN or mirror halves of an MD in context of Extended Distance Cluster (XDC).
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Technical white paper | Using udev to simplify HP Serviceguard for Linux configuration CCISS Writing udev rules is not required for CCISS devices (MSA500 family). Because of the nature of the MSA500 family, device names will not change unless a device is deleted. To prevent issues with Serviceguard, do not delete a MSA500 device whose identifier is between two other devices. Naming for mirror halves of an MD device It is recommended to use persistent names using udev for the mirror halves of an MD device.
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Technical white paper | Using udev to simplify HP Serviceguard for Linux configuration Suppose there exists a soft link from /dev/mapper/mpath1 to /dev/dm-1 and /dev/mapper/mpath1 has a partition /dev/mapper/mpath1_part1. If there exists a softlink from /dev/mapper/mpath1_part1 to /dev/dm-2, append the following rule in /etc/udev/rules.d/10-HP-Local.rules file: SUBSYSTEM==”block”, KERNEL==”dm*”, PROGRAM=”/bin/sh /root/myscript.
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Technical white paper | Using udev to simplify HP Serviceguard for Linux configuration If you are using multipath devices (DM devices), append the following rule to the /etc/udev/rules.d/10-HP-Local.
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Technical white paper | Using udev to simplify HP Serviceguard for Linux configuration For Red Hat 6, Novell SLES 11 SP1 and Novell SLES 11 SP2: # udevadm trigger In some cases, it may also be necessary to reboot the system. The links are created under the directory mentioned in the udev_root path variable that is configured in the /etc/udev/udev.conf file. For example, the link shown in step 1 (Creating rules for a device) is created as $udev_root/hpdev/mylink-sda.