topic Re: file based replication in Operating System - Linux

file based replication

Maaz — Mon, 31 Jan 2011 09:57:11 GMT

File-based replication does offer the ability to replicate only specific files. However, if as little as one bit of data has changed on a very large file, the entire file is considered as having changed and will be replicated with most solutions.

is it the case with 'rsync' too ? or rsync only replicates the delta ?

Regards
Maaz

Re: file based replication

Lucifer Megacruel — Mon, 31 Jan 2011 10:28:36 GMT

Hi,

man rsync gives this

"....It is famous for its delta-transfer algorithm, which reduces the amount of data sent over the network by sending only the differences between the source files and the existing files in the destination......"

Truly Evil
Lucifer Megacruel

Re: file based replication

Alzhy — Mon, 31 Jan 2011 16:29:27 GMT

"is it the case with 'rsync' too ? or rsync only replicates the delta ?"

Yes. Unfortunately.

One solution I am currently brewing in my LAB is DRBD -- an open source block level based Storage replication/clustering solution -- so say you have a 50GB file and only a few bits changed on it -- the other site/machine will only update those changed bits...

http://www.drbd.org/

See if it works for you.

Re: file based replication

Emil Velez — Mon, 31 Jan 2011 23:45:19 GMT

What are you trying to do

Disaster recovery to another site. There are many options with disk arrays that could be used.

Local replication since another system also needs access to the files. Have you considered the cluster file system ?