AIX Version 4.3 Differences Guide

Chapter 5. Logical Volume Manager Enhancements
AIX 4.3, AIX 4.3.1, and AIX 4.3.2 received enhancements to the logical volume
group scalability, synchronization performance, and on-line mirror backup
functions. These changes enhance AIX’s image as a robust and powerful
operating system for increasingly demanding customer requirements.
In this chapter, the major new features of logical volume manager are described.
5.1 Logical Volume Synchronization
The following commands now support the -P flag to allow the user to specify the
number of LPs to sync. in parallel.
• /usr/sbin/syncvg
• /usr/sbin/lresynclv
The -P flag is followed on the command line by the number of partitions to be
synchronized as follows:
syncvg [-i] [-f] [-H] [-P NumParalleLPs] {-l|-p|-v} Name[-P num_parallel_lps]
lresynclv [-H] [-P NumParalleLps] -l LVid
The valid range for NumParallelLps is 1 to 32. If the number entered is less than
one then num_parallel_lps defaults to one. If the number entered is greater than
32 then num_parallel_lps will be set to 32.
The mklv and chlv commands were updated in AIX 4.3.0 to allow synchronized
updates of volume groups in a concurrent environment. All nodes that share disks
must be available at the time the updated command is issued in order for updates
to take place. If a system already has an existing LV with the same name as a
new one being added to another system, the command will fail. Other conflicts
are also detected to provide stable LV updates in a shared environment. All
systems must be running AIX 4.3.0 or higher in order to use this enhancement.
5.2 importvg Learning Mode
A new option has been created for the LVM importvg command. This new option,
-L for learning mode, is executed on a shared volume group in a cluster. It allows
the LVM actions of creation, deletion, or extension performed on one cluster node
to be propagated to other nodes connected to the same shared volume group.
importvg [-V MajorNumber] [-y VolumeGroup] [-f] [-c] [-x] | [-L VolumeGroup] [
-n] [-F] PhysicalVolume
The -L flag takes a volume group and learns about possible changes performed
to that volume group. Any new logical volumes created as a result of this
command inherit the ownership, group identification, and permissions of the /dev
special file for the volume group listed in the -y flag.
To use this feature, note the following:
• The volume group must not be in an active state on the system executing the
-L flag.
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