Novell LINUX ENTERPRISE SERVER 10 SP3 - ARCHITECTURE-SPECIFIC, Руководство администратора

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52 SLES 10 SP3: Storage Administration Guide
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5.3.3 Using mdadm for Multipathed Devices
In SUSE Linux Enterprise Server 10, Udev is the default device handler, and devices are
automatically known to the system by the Worldwide ID instead of by the device node name. This
resolves problems in previous releases where
mdadm.conf
and
lvm.conf
did not properly
recognize multipathed devices.
Just as for LVM2,
mdadm
requires that the devices be accessed by the ID rather than by the device
node path. Therefore, the
DEVICE
entry in
/etc/mdadm.conf
should be set as follows:
DEVICE /dev/disk/by-id/*
This is the default handling in SUSE Linux Enterprise Server 10 and later, as noted above.
To verify that
mdadm
is installed:
1 Ensure that the
mdadm
package is installed by entering the following at a terminal console
prompt:
rpm -q mdadm
If it is installed, the response repeats the package name and provides the version information.
For example:
mdadm-2.6-0.11
If it is not installed, the response reads:
package mdadm is not installed
For information about modifying the
/etc/lvm/lvm.conf
file, see Section 5.2.3, “Using LVM2 on
Multipath Devices,” on page 46 .
5.3.4 The Linux multipath(8) Command
Use the Linux
multipath(8)
command to configure and manage multipathed devices.
General syntax for the
multipath(8)
command:
multipath [-v verbosity] [-d] [-h|-l|-ll|-f|-F] [-p failover | multibus |
group_by_serial | group_by_prio| group_by_node_name ]
General Examples
Configure multipath devices:
multipath
Configure a specific multipath device:
multipath devicename
Replace devicename with the device node name such as
/dev/sdb
(as shown by udev in the
$DEVNAME variable), or in the major:minor format.
Selectively suppress a multipath map, and its device-mapped partitions:
multipath -f