Veritas Storage Foundation 5.1 SP1 Cluster File System Administrator"s Guide (5900-1738, April 2011)

Table 2-4
Activation modes for shared disk groups (continued)
DescriptionActivation mode
The node has read access to the disk group and denies write access
for all other nodes in the cluster. The node has no write access to the
disk group. Attempts to activate a disk group for either of the write
modes on other nodes fail.
readonly (ro)
The node has read access to the disk group. The node has no write
access to the disk group, however other nodes can obtain write access.
sharedread
(sr)
The node has write access to the disk group.sharedwrite
(sw)
The node has neither read nor write access to the disk group. Query
operations on the disk group are permitted.
off
Table 2-5 summarizes the allowed and conflicting activation modes for shared
disk groups.
Table 2-5
Allowed and conflicting activation modes
sharedwritesharedreadreadonlyexclusive-
write
Disk group
activated in
cluster as...
FailsSucceedsFailsFailsexclusivewrite
FailsSucceedsSucceedsFailsreadonly
SucceedsSucceedsSucceedsSucceedssharedread
SucceedsSucceedsFailsFailssharedwrite
To share disk groups
■ Shared disk groups can be automatically activated in any mode during disk
group creation or during manual or auto-import. To control auto-activation
of shared disk groups, the /etc/default/vxdg file must be created.
The /etc/default/vxdg file must contain the following lines:
enable_activation=true
default_activation_mode=activation-mode
The activation-mode is one of exclusivewrite, readonly, sharedread,
sharedwrite, or off.
Storage Foundation Cluster File System architecture
About Veritas Volume Manager cluster functionality
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