Partitioning Multipathed Devices; Configuring The Server For Multipathing - Novell LINUX ENTERPRISE SERVER 10 SP2 - STORAGE ADMINISTRATION GUIDE 05-15-2009 Administration Manual

Install the Linux HBA driver module. Upon module installation, the driver automatically scans
the HBA to discover any SAN devices that have permissions for the host. It presents them to
the host for further configuration.
NOTE: Ensure that the HBA driver you are using does not have native multipathing enabled.
See the vendor's specific instructions for more details.
After the driver module is loaded, discover the device nodes assigned to specific array LUNs or
partitions.
If the LUNs are not seen by the HBA driver,
are seen correctly by the operating system. When the LUNs are not seen by the HBA driver, check
the zoning setup of the SAN. In particular, check whether LUN masking is active and whether the
LUNs are correctly assigned to the server.
If the LUNs are seen by the HBA driver, but there are no corresponding block devices, additional
kernel parameters are needed to change the SCSI device scanning behavior, such as to indicate that
LUNs are not numbered consecutively. For information, see
(http://support.novell.com/techcenter/sdb/en/2005/06/drahn_scsi_scanning.html)
Support Knowledgebase.

5.4.2 Partitioning Multipathed Devices

Partitioning devices that have multiple paths is not recommended, but it is supported.
SUSE Linux Enterprise Server 10
In SUSE Linux Enterprise Server 10, you can use the
multipathed devices without rebooting. You can also partition the device before you attempt to
configure multipathing by using the Partitioner function in YaST2 or by using a third-party
partitioning tool.
SUSE Linux Enterprise Server 9
In SUSE Linux Enterprise Server 9, if you want to partition the device, you should configure its
partitions before you attempt to configure multipathing by using the Partitioner function in YaST2 or
by using a third-party partitioning tool. This is necessary because partitioning an existing
multipathed device is not supported. Partitioning operations on multipathed devices fail if
attempted.
If you configure partitions for a device, DM-MP automatically recognizes the partitions and
indicates them by appending p1 to pn to the device's ID, such as
/dev/disk/by-id/26353900f02796769p1
To partition multipathed devices, you must disable the DM-MP service, partition the normal device
node (such as

5.4.3 Configuring the Server for Multipathing

The system must be manually configured to automatically load the device drivers for the controllers
to which the multipath I/O devices are connected within the
driver module to the variable INITRD_MODULES in the file
54 SLES 10 SP2: Storage Administration Guide
), then reboot to allow the DM-MP service to see the new partitions.
/dev/sdc
can be used to check whether the SCSI devices
lsscsi
Options for SCSI Device Scanning
tool to create partitions on
kpartx
. Therefore add the needed
INITRD
/etc/sysconfig/kernel
in the Novell
.