See
lvm for common options.
Exactly one of --mirrors or --snapshot arguments required.
-m, --mirrors Mirrors
Specifies the degree of the mirror you wish to create. For example, "-m 1" would convert the original logical volume to a mirror volume with 2-sides; that is, a linear volume plus one copy.
--mirrorlog {disk|core}
Specifies the type of log to use. The default is disk, which is persistent and requires a small amount of storage space, usually on a separate device from the data being mirrored. Core may be useful for short-lived mirrors: It means the mirror is regenerated by copying the data from the first device again every time the device is activated - perhaps, for example, after every reboot.
--corelog
The optional argument "--corelog" is the same as specifying "--mirrorlog core".
-R, --regionsize MirrorLogRegionSize
A mirror is divided into regions of this size (in MB), and the mirror log uses this granularity to track which regions are in sync.
-b, --background
Run the daemon in the background.
-i, --interval Seconds
Report progress as a percentage at regular intervals.
-s, --snapshot
Create a snapshot from existing logical volume using another existing logical volume as its origin.
-c, --chunksize ChunkSize
Power of 2 chunk size for the snapshot logical volume between 4k and 512k.
-Z, --zero y|n
Controls zeroing of the first KB of data in the snapshot. If the volume is read-only the snapshot will not be zeroed.