Veritas Storage Foundation Intelligent Storage Provisioning 5.0 Solutions Guide, HP-UX 11i v3, First Edition, May 2008

36 Remote mirror solutions
About Remote Mirror configurations
To check which disks are registered to a site, use this form of the vxdisk
command:
# vxdisk listtag
Note: All the disks in a disk group must be registered to one of the sites
before you can set the siteconsistent attribute on the disk group in the
next step.
3 Turn on the site-based allocation requirement for a site that is registered to
a disk group. Use the following form of the vxdg command for each site at
which site-based allocation is required:
# vxdg -g diskgroup [-f] addsite sitename
Each volume is checked to ensure that it has at least one plex at each site,
and the command fails if this condition is not met unless the volume’s
allsites attribute is set to off. If the -f option is specified, the command
does not fail, but instead it sets the
allsites attribute for the volume to
off.
4 Turn on the site consistency requirement for the disk group using the
following form of the
vxdg command:
# vxdg -g diskgroup set siteconsistent=on
This command fails if any of the following conditions are not met:
■ Each of the disks in the disk group must be registered to one of the
sites.
■ Each volume in the disk group must have at least one complete plex at
each site.
■ The disk group must not contain any RAID-5 volumes.
To verify whether site consistency has been enabled for a disk group, use
the following command:
# vxdg list diskgroup | grep siteconsistent
flags: siteconsistent
5 To set the site consistency requirement when creating a volume in the disk
group, specify the
siteconsistent attribute to the vxassist make
command, for example:
# vxassist [-g diskgroup ] make volume size \
nmir=4 siteconsistent={on|off}
By default, a volume inherits the value of siteconsistent that is set on its
disk group. If a volume is intended to be site consistent, the number of
mirrors that are specified should be a multiple of the number of sites.
ISP saves the intent to provision volumes across sites and follows these
rules for future allocations.