Chapter 4. File System and Storage Management
--nosync option for CLVM mirrored volume extension
Clustered LVM includes a new --nosync option for extending mirrored logical volumes. When the --nosync option is specified, extending a clustered mirrored logical volume does not cause the volume to get synchronized after the extension, potentially skipping resource intensive synchronization of empty data.
After executing the lvextend command with the -r/--resizefs option, the ext4 file system automatically re-sizes itself. Performing a manual re-size with the resize2fs is no longer required.
With Red Hat Enterprise Linux 5.8, NFS clients are allowed to use insecure ports (that is, 1024 and above).
LVM no longer scans multipath member devices (underlying paths for active multipath devices) and prefers top level devices. This behavior can be switched off using the multipath_component_detection option in the /etc/lvm/lvm.conf.