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5.7. Online Data Relocation

You can move data while the system is in use with the pvmove command.
The pvmove command breaks up the data to be moved into sections and creates a temporary mirror to move each section. For more information on the operation of the pvmove command, see the pvmove(8) man page.


In order to perform a pvmove operation in a cluster, you should ensure that the cmirror and cmirror-kmod packages are installed and that the cmirror service is running. The cmirror-kmod package that must be installed depends on the kernel that is running. For example, if the running kernel is kernel-largesmp, it is necessary to have cmirror-kmod-largesmp for the corresponding kernel version.
The following command moves all allocated space off the physical volume /dev/sdc1 to other free physical volumes in the volume group:
# pvmove /dev/sdc1
The following command moves just the extents of the logical volume MyLV.
# pvmove -n MyLV /dev/sdc1
Since the pvmove command can take a long time to execute, you may want to run the command in the background to avoid display of progress updates in the foreground. The following command moves all extents allocated to the physical volume /dev/sdc1 over to /dev/sdf1 in the background.
# pvmove -b /dev/sdc1 /dev/sdf1
The following command reports the progress of the move as a percentage at five second intervals.
# pvmove -i5 /dev/sdd1