About bulk transfer with secondary logging

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.

For example:

# 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
att:      rlinks=rlk_c1059rhel6_rvg
flags:    closed primary enabled attached bulktransfer
device:   minor=23002 bdev=199/23002 cdev=199/23002 \
perms:    user=root group=root mode=0600