Red Hat ENTERPRISE LINUX 5 - LOGICAL VOLUME MANAGER ADMINISTRATION Manual page 95

clustered_disk
The mirror is clustered and the mirror log is kept on disk. This log type takes 3 - 5 arguments:
logdevice regionsize UUID [[no]sync] [block_on_error]
LVM maintains a small log which it uses to keep track of which regions are in sync with the mirror
or mirrors. The regionsize argument specifies the size of these regions.
In a clustered environment, the UUID argument is a unique identifier associated with the mirror log
device so that the log state can be maintained throughout the cluster.
The optional [no]sync argument can be used to specify the mirror as "in-sync" or "out-of-sync".
The block_on_error argument is used to tell the mirror to respond to errors rather than ignoring
them.
#log_args
number of log arguments that will be specified in the mapping
logargs
the log arguments for the mirror; the number of log arguments provided is specified by the #log-
args parameter and the valid log arguments are determined by the log_type parameter.
#devs
the number of legs in the mirror; a device and an offset is specifed for each leg.
device
block device for each mirror leg, referenced by the device name in the filesystem or by the major
and minor numbers in the format major:minor. A block device and offset is specified for each
mirror leg, as indicated by the #devs parameter.
offset
starting offset of the mapping on the device. A block device and offset is specified for each mirror
leg, as indicated by the #devs parameter.
The following example shows a mirror mapping target for a clustered mirror with a mirror log kept on
disk.
0 52428800 mirror clustered_disk 4 253:2 1024 UUID block_on_error 3 253:3 0
253:4 0 253:5 0
0
starting block in virtual device
52428800
length of this segment
mirror clustered_disk
mirror target with a log type specifying that mirror is clustered and the mirror log is maintained on
disk
4
4 mirror log arguments will follow
The mirror Mapping Target
83