Managing Serviceguard Nineteenth Edition, Reprinted June 2011

Where cDSFs Reside
cDSFs reside in two new HP-UX directories, /dev/cdisk for cluster-wide block devicefiles and
/dev/rcdisk for cluster-wide character devicefiles. Persistent DSFs that are not cDSFs continue
to reside in /dev/disk and /dev/rdisk, and legacy DSFs (DSFs using the naming convention
that was standard before HP–UX 11i v3) in /dev/dsk and /dev/rdsk. It is possible that a
storage device on an 11i v3 system could be addressed by DSFs of all three types of device —
but if you are using cDSFs, you should ensure that you use them exclusively as far as possible.
NOTE: Software that assumes DSFs reside only in /dev/disk and /dev/rdisk will not find
cDSFs and may not work properly as a result; as of the date of this manual, this was true of the
Veritas Volume Manager, VxVM.
Limitations of cDSFs
• cDSFs are supported only within a single cluster; you cannot define a cDSF group that crosses
cluster boundaries.
• A node can belong to only one cDSF group.
• cDSFs are not supported by VxVM, CVM, CFS, or any other application that assumes DSFs
reside only in /dev/disk and /dev/rdisk.
• cDSFs do not support disk partitions.
Such partitions can be addressed by a device file using the agile addressing scheme, but not
by a cDSF.
LVM Commands and cDSFs
Some HP-UX commands have new options and behavior to support cDSFs, specifically:
• vgimport –C causes vgimport (1m) to use cDSFs.
• vgscan –C causes vgscan (1m) to display cDSFs
See the manpages for more information.
The following new HP-UX commands handle cDSFs specifically:
• vgcdsf(1m) converts all persistent DSFs in a volume group to cDSFs.
Legacy DSFs in the volume group will not be converted, but you can use HP-UX the vgdsf
script to convert these legacy DSFs to persistent DSFs if you need to. For more information on
the vgdsf script, see the white paper LVM Migration from Legacy to Agile Naming Model
at http://http://www.hp.com/go/hpux-core-docs. For more information on vgcdsf, see the
manpage.
• io_cdsf_config (1m) displays information about cDSFs.
See the manpage for more information.
About Easy Deployment
In the past you had two main choices for configuring a cluster: using Serviceguard commands, as
described in detail in Chapter 5 (page 149), or using the Serviceguard Manager GUI (or some
combination of these two methods). As of Serviceguard A.11.20, there is a third option, called
Easy Deployment.
100 Planning and Documenting an HA Cluster