Novell LINUX ENTERPRISE SERVER 11 - STORAGE ADMINISTRATION GUIDE 2-23-2010, Руководство администратора, Страница: 23 / 140

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2.8 User-Friendly Names for Multipathed Devices
A change in how multipathed device names are handled in the
/dev/disk/by-id
directory (as
described in Section 2.6, “Device Name Persistence in the /dev/disk/by-id Directory,” on page 22 )
affects your setup for user-friendly names because the two names for the device differ. You must
modify the configuration files to scan only the device mapper names after multipathing is
configured.
For example, you need to modify the
lvm.conf
file to scan using the multipathed device names by
specifying the
/dev/disk/by-id/dm-uuid-.*-mpath-.*
path instead of
/dev/disk/by-id
.
2.9 Advanced I/O Load-Balancing Options for
Multipath
The following advanced I/O load-balancing options are available in additon to round-robin for
Device Mapper Multipath:
Š
Least-pending
Š
Length-load-balancing
Š
Service-time
For information, see path_selector in “Understanding Priority Groups and Attributes” on page 62 .
2.10 Location Change for Multipath Tool Callouts
The
mpath_*
prio_callouts for the Device Mapper Multipath tool have been moved to shared
libraries in
/lib/libmultipath/lib*
. By using shared libraries, the callouts are loaded into
memory on daemon startup. This helps avoid a system deadlock on an all paths down scenario
where the programs would have to be loaded from the disk, which might not be available at this
point.
2.11 Change from mpath to multipath for
mkinitrd -f Option
The option for adding Device Mapper Multipath services to the
initrd
has changed from
-f
mpath
to
-f multipath
.
To make a new
initrd
, the command is now:
mkinitrd -f multipath