Managing Serviceguard Sixteenth Edition, March 2009

2) single heartbeat network with standby LAN card(s)
3) single heartbeat network with APA.
CVM 3.5 supports only options 2 and 3. Options 1 and 2 are the minimum recommended
configurations for CVM 4.1 and later.
Comparison of Volume Managers
The following table summarizes the advantages and disadvantages of the volume
managers.
Table 3-4 Pros and Cons of Volume Managers with Serviceguard
TradeoffsAdvantagesProduct
• Lacks flexibility and extended
features of some other volume
managers
• Software is provided with all versions
of HP-UX.
• Provides up to 3-way mirroring using
optional Mirrordisk/UX software.
• Dynamic multipathing (DMP) is active
by default as of HP-UX 11i v3.
• Supports exclusive activation as well as
read-only activation from multiple
nodes
• Can be used to configure a cluster lock
disk
• Supports multiple heartbeat subnets;
the one with the faster failover time is
used to re-form the cluster.
Logical Volume
Manager (LVM)
• Lacks extended features of other
volume managers
• Software mirroring
• Lower cost solution
Mirrordisk/UX
• Lacks the flexibility and extended
features of some other volume
managers.
• Limited mirroring support
• Provided free with SGeRAC for
multi-node access to RAC data
• Supports up to 16 nodes in shared
read/write mode for each cluster
• Supports exclusive activation
• Supports multiple heartbeat subnets.
• Online node configuration with
activated shared volume groups (using
specific SLVM kernel and Serviceguard
revisions)
Shared Logical
Volume Manager
(SLVM)
116 Understanding Serviceguard Software Components