[Gluster-devel] Uh, another gotcha with AFR, pre-existing data specific

[Brandon Lamb]

I just did some testing, and came to the conclusion that trying to
setup afr using one server with pre-existing data and a blank server,
and copying your data and removing xattr's on the copied data then
initiating afr DOES NO GOOD.

server1 - 400 megs of data in 10 tarballs, removed all xattr
server2 - copied the files from server1
server1 - started glusterfsd, then ran setfattr
trusted.glusterfs.version to 1, files on server2 have no xattr.

At this point i should have identical copies of data *assuming* i had
no writes in between.

SO, now in a client i do head -c 1 file0.tar.bz2 and it seems that
since files on server2 have NO xattr, it copies them all over again!!!

So, is there no viable way to PRECOPY a copy of pre-existing data?
Looks like what we will have to do is a directory by directory
migration or stop all services that rely on the data store, copy the
data to both machines while there are no writes (no changes) going on,
then start everhting back up.

For those of us that need this in a mail storage scenario, this is not
good. I cant stop my entire mail system for 4 hours while I copy over
170 gigs of 4 million files.

Now I will have to think of something a little more tricky like moving
a single maildir subdirectory letter at a time.

Thoughts, comments, suggestions?