To effectively use network bandwidth for replication, data is replicated to a disaster recovery (DR) site in bulk at 256 KB. This bulk data transfer reduces VVR CPU overhead and increases the overall replication throughput. With compression enabled, bulk data transfer improves the compression ratio and reduces the primary side CPU usage.
Bulk transfer requires secondary logging to be enabled, and is supported with both TCP and UDP protocols. Bulk transfer is not supported with bunker replication, and in cross-platform replication.
Bulk transfer for replication is automatically enabled from disk group version 190. If bulk transfer is enabled, the vxprint -Vl command displays bulktransfer under the RVG flags field.
# vxprint -Vl -g vvrdg rvg Rvg: rvg info: rid=0.1061 version=2 rvg_version=45 last_tag=1 state: state=ACTIVE kernel=ENABLED assoc: datavols=vol srl=arl rlinks=rlk_c1059rhel6_rvg exports=(none) vsets=(none) att: rlinks=rlk_c1059rhel6_rvg flags: closed primary enabled attached bulktransfer device: minor=23002 bdev=199/23002 cdev=199/23002 \ path=/dev/vx/dsk/vvrdg/rvg perms: user=root group=root mode=0600