[Gluster-users] novice kind of question.. replication(raid)

[Vikas Gorur]

>> server_1  <->  server_2  <->  server_3
>>     |                        |                        |
>>    ^                      ^                       ^
>> /watch_me         /watch_me       /watch_me
>> 
>> so no mounts, a process changes something in this local /watch_me on
>> server_1
>> server_1 propagates(obviously working through the logic) the change to
>> other servers and vice versa
>> 
>> is it possible to, maybe by introducing client part of config into
>> glusterfsd.vol,
>> to have it like this? without having a client have to mount/configure
>> replication?


This is easy to do. Have a directory named /backend on all three servers. Run a GlusterFS
server there which simply exports this backend directory. Write a client volume file which has
replication in it and has these three servers as its children. Using this client volume file,
mount on /watch_me on all three servers.

Now when a process writes to /watch_me on any server, the changes are propagated to all
the three servers.

To understand how to write volume files, you can try this command and take a look at the files
it generates. This will generate files for a 2-server replicate setup, but you can easily extend
it to three servers.

$ glusterfs-volgen --raid=1 --name=testvolume server_1:/backend server_2:/backend

(you can give an IP address instead of a name like server_1).

------------------------------
Vikas Gorur
Engineer - Gluster, Inc.
+1 (408) 770 1894
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