dm developers,
I'm in need of an asynchronous replication method for active/passive clusters using direct-attached disks. Please advise if you know tools (other than drdb an rsync) to do the job. (How goes dm-replicator btw ?).
Pending an existing project, I toyed with a replication scheme I'd like to sketch here for comments and fool-proofing.
Source and destination are logical volumes : lv_src => lv_dst
Upon cold start lv_src and lv_dst are unsynchronized.
==== pseudo-code start
snap lv_src (lv_src_snap0)
full copy lv_src_snap0 on lv_dst
while true:
wait n seconds
snap lv_src (lv_src_snap1)
for each changed chunk in lv_src_snap0 cow table:
copy chunk from lv_src_snap1 to lv_dst
drop lv_src_snap0, and rename lv_src_snap1 to lv_src_snap0
==== pseudo-code end
Snapshoting the lv_dst would make sense as a rollback safety net ... even if the rollback is a bit hard pending the snapshot merging patchset inclusion.
If this sketch looks sane to you, I'm interested in how to list the changed chunks for a snap. A pointer to existing code would do great.
Regards,
cvaroqui
--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel
