System information

Advanced Functions
5-8
RHEL5: mpath-xxx-x.src-rhel5.rpm
SuSe10: mpath-xxx-x.src-sles10.rpm
1. Install the RPM by typing rpm -ivh mpath-xxx-x.xxx-xxxx.rpm. This not only installs the driver but also starts the
multipathd service like the procedures described for the single-controller system.
2. To build a driver binary, follow the steps below:
2.1 Type rpm -ivh mpath-xxx-x.src-xxxx.rpm to install the source code package
2.2 Change working directory to /usr/src/packages/SPECS and type rpmbuild -bb mpath.spec
2.3 Change working directory to /usr/src/redhat/packages/RPMS/”your ARCH” and Type rpm -ivh mpath-xxx-
x.rpm
3. Edit /etc/multipath.conf to specify the vendor names, product names, priority callout function, and hardware
handler. An example is illustrated as below:
• Uninstall and stop the multipathd service
(Redundant-Controller System)
Simply type rpm -e mpath-xxx-x
• Access to multi-path devices
1. If no error message is displayed during the installation and startup of the multipathd service, you’ve successfully
started the multipathd, and you can now go to /dev/ to find the multi-path devices, which are named as dm-x, where
x is a number assigned by the DM driver.
2. You can create partitions on /dev/dm-x using fdisk or parted command. To access the partitions, you need also to
use kpartx to create DM devices in the /dev/.
• Manage multipathd service
1. To view the LUNs of the attached RAID systems, type cat /proc/scsi/scsi, and similar outputs are displayed as
below:
2. To check if multipathd service has been activated or not, type chkconfig --list multipathd.
3. To check if service has been running or not, type serivce -- status-all.The multipathd provides several commands for
configuring the paths as well as showing path and device information. Type multipathd -k to enter its interactive
mode.
devices {
device {
vendor "vendorname"
product "productmodelname"
path_grouping_policy group_by_prio
getuid_callout "/sbin/scsi_id -p 0x80 -g -u -s /block/%n"
prio_callout "/sbin/acs_prio_alua %d"
hardware_handler "1 mpath"
path_checker hp_sw
path_selector "round-robin 0"
failback immediate
no_path_retry queue
rr_min_io 100
product_blacklist LUN_Z
}
}