[Gluster-devel] Documentation on 'gluster volume replace-brick' out of date?

[Anders Blomdell]

While looking into "Symlink mtime changes when rebalancing"
(https://bugzilla.redhat.com/show_bug.cgi?id=1122443), I found that 
it looks like the documentation on 'gluster volume  replace-brick' is 
out of date (v3.7dev-34-g67a6f40), gluster.8 says:

  volume  replace-brick  <VOLNAME> (<BRICK> <NEW-BRICK>) start|pause|abort|status|commit
    Replace the specified brick.

while 'gluster volume replace-brick volname old-brick new-brick start' says:
  All replace-brick commands except commit force are deprecated. Do you want to continue? (y/n)

Am I right to assume that the correct way migrate data to a new brick, is:

  # gluster volume add-brick volname new-brick
  # gluster volume remove-brick volname old-brick start
  ... wait for completion, would maybe be nice to have a
  ...   gluster volume volname wait <UUID>
  # gluster volume remove-brick volname old-brick commit
  Removing brick(s) can result in data loss. Do you want to Continue? (y/n)
  ... Would be nice if the fact that migration is complete was reflected in
  ... the dialog.

AFAICT this also means that there is no way to replace a single brick in
a replicated volume in such a way that all old brick replicas are online until the
new brick is fully healed/populated, meaning that with replica a count 2, we only 
have one active replica until healing is done.

/Anders

-- 
Anders Blomdell                  Email: anders.blomdell at control.lth.se
Department of Automatic Control
Lund University                  Phone:    +46 46 222 4625
P.O. Box 118                     Fax:      +46 46 138118
SE-221 00 Lund, Sweden