Bug 1027270

+++ This bug was initially created as a clone of Bug #1025240 +++

Description of problem:
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Grammar: Usage: volume remove-brick <VOLNAME> [replica <COUNT>] <BRICK> ... {start|stop|status|commit|force}

remove-brick can be executed without any options i.e we need not have to use any of these options : "{start|stop|status|commit|force}". Hence We should be placing these options in between "[ ]" brackets. 


Command execution output message improvements:
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Command 1 :  gluster v remove-brick replica 2 rhs-client13:/rhs/bricks/b3 start

wrong brick type: 2, use <HOSTNAME>:<export-dir-abs-path>
Usage: volume remove-brick <VOLNAME> [replica <COUNT>] <BRICK> ... {start|stop|status|commit|force}

In this case we have not specified the volume name. The error message should just be the "Usage". The additional message :"wrong brick type: 2, use <HOSTNAME>:<export-dir-abs-path>" is confusing and doesn't make any sense in this context. Why would the brick type be "<HOSTNAME>:<export-dir-abs-path>" ?

Command 2 : gluster v remove-brick vol_rep replica 2 rhs-client13:/rhs/bricks/b3 start

volume remove-brick start: failed: Rebalancing not needed when reducing replica count. Try without the 'start' option

a. Instead of "Rebalancing not needed" message it would be appropriate to replace it with "Migration of data is not needed"

b. Try without the 'start' option can be replaced with "Use 'force' option"


Documentation improvements:
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Documentation link : http://documentation-devel.engineering.redhat.com/docs/en-US/Red_Hat_Storage/2.1-RC/html/Administration_Guide/sect-User_Guide-Managing_Volumes-Shrinking.html

1. Existing documentation doesn't have information about the usage of remove-brick command when we are reducing the replica count i.e "gluster volume remove-brick VOLNAME replica <replica_count> BRICK force". The changes which went into the patch "https://code.engineering.redhat.com/gerrit/#/c/11755/" needs to documented. 


Version-Release number of selected component (if applicable):
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glusterfs 3.4.0.35.1u2rhs built on Oct 21 2013 14:00:58

--- Additional comment from RHEL Product and Program Management on 2013-10-31 06:09:47 EDT ---

Since this issue was entered in bugzilla, the release flag has been
set to ? to ensure that it is properly evaluated for this release.

--- Additional comment from Ravishankar N on 2013-11-06 08:00:13 EST ---

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Command 1 :  gluster v remove-brick replica 2 rhs-client13:/rhs/bricks/b3 start

wrong brick type: 2, use <HOSTNAME>:<export-dir-abs-path>
Usage: volume remove-brick <VOLNAME> [replica <COUNT>] <BRICK> ... {start|stop|status|commit|force}
-----------------------------------
Though the 'wrong brick type 2' log might not make sense at first glance, the 'Usage' log helps interpret the output in a meaningful way, more so for sys-admins. According to the Usage syntax, the word that follows 'gluster v remove-brick' is parsed as the VOLNAME. Here it happens to be 'replica'. If the next phrase is the optional keyword 'replica', the subsequent argument must be an integer (the replica count). Since that isn't the case, the CLI expects that the next phrase ('2' in this case) to be a brick-path of the format "<HOSTNAME>:<export-dir-abs-path>". If there is a format mismatch it gives out the error message.

On a lighter note, the message is akin to a cryptic compiler error which might not make full sense immediately but tells you exactly what the error is :)

The other improvements in the description can be addressed.