Installation Guide

VxVM 5.1 SP1 does not support snapshots of RAID 5 volumes.
• Dirty Region Logging
Dirty Region Logging (DRL) keeps track of the regions that have been changed because I/O
writes to a mirrored volume. The DRL uses this information to recover only those portions of
the volume that need to be recovered, thereby speeding up recovery after a system crash.
• SmartMove™ Feature
SmartMove reduces the time and I/O required to attach or reattach a plex to an existing
VxVM volume, in the specific case where a VxVM volume has a VxFS file system mounted on
it. The SmartMove feature uses the VxFS information to detect free extents and avoids copying
them.
• Enhancements to the Dynamic Multipathing Feature
This release provides a number of enhancements to the DMP features of VxVM. These
enhancements simplify administration and improve display of detailed information about the
connected storage. Following are the enhancements to the DMP feature:
◦ Dynamic multipathing attributes are now persistent
◦ Improved dynamic multipathing device naming
◦ Default behavior modified for I/O throttling
◦ Specifying a minimum number of active paths
◦ Enhanced listing of subpath
◦ Enhanced I/O statistics
◦ Making DMP restore options persistent
◦ New log file location for DMP events
◦ Extended device attributes displayed in the vxdisk list command
◦ Displaying the use_all_paths attribute for an enclosure
◦ Viewing information about the ASLs installed on the system
◦ Displaying the number of LUNs in an enclosure
◦ Displaying the LUN serial number
◦ Displaying HBA details
◦ New exclude and include Options for the vxdmpadm command
◦ New command for reporting DMP node information
◦ Setting attributes for all enclosures
◦ Support for ALUA JBOD devices
• VxVM Powerfail Timeout (PFTO) feature disabled in the HP-UX Native Multipathing Devices
By default, the use of PFTO is now disabled in the HP-UX native multipathing devices. As a
result, the native multipathing disk I/O can consume additional service time to complete an
I/O successfully. In case of DMP devices, the use of PFTO is enabled by default.
For information on recommendations to maintain high levels of I/O robustness, refer to “I/O
Robustness Recommendations” (page 62).
• Support for LVM version 2 Volume Groups
The LVM version 2 volume groups are now partially supported. VxVM now identifies and
protects the LVM version 2 volume groups. However, the LVM version 2 volume groups cannot
be initialized or converted.
Veritas Volume Manager (VxVM) 11