Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

# by default, limit mirroring log lengths to 32Kbytes
max_regionloglen=32k
# use 64K as the default stripe unit size for regular volumes
stripe_stwid=64k
# use 16K as the default stripe unit size for RAID-5 volumes
raid5_stwid=16k
Using the SmartMove™ feature while attaching a plex
The SmartMove™ feature 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 avoid copying them.
The SmartMove feature is enabled by default.
The SmartMove feature takes effect when a plex is attached or reattached using
the vxplex, vxsd, or vxassist commands.
Note: The file system must be mounted to get the benefits of the SmartMove™
feature.
When the SmartMove feature is on, less I/O is sent through the host, through the
storage network and to the disks or LUNs. The SmartMove feature can be used
for faster plex creation and faster array migrations.
The SmartMove feature enables migration from a traditional LUN to a thinly
provisioned LUN, removing unused space in the process.
For more information, see the section on migrating to thin provisioning in the
Veritas Storage Foundation™ Advanced Features Administrator's Guide.
Discovering the maximum size of a volume
To find out how large a volume you can create within a disk group, use the
following form of the vxassist command:
# vxassist [-g diskgroup] maxsize layout=layout [attributes]
For example, to discover the maximum size RAID-5 volume with 5 columns and
2 logs that you can create within the disk group, dgrp, enter the following
command:
303Creating volumes
Discovering the maximum size of a volume