[Pacemaker] [PATCH]Bug 2567 - crm resource migrate should support an optional "role" parameter

[Holger Teutsch]

Hi Dejan,

On Tue, 2011-04-05 at 12:27 +0200, Dejan Muhamedagic wrote:
> On Tue, Apr 05, 2011 at 12:10:48PM +0200, Holger Teutsch wrote:
> > Hi Dejan,
> > 
> > On Tue, 2011-04-05 at 11:48 +0200, Dejan Muhamedagic wrote:
> > > Hi Holger,
> > > 
> > > On Mon, Apr 04, 2011 at 09:31:02PM +0200, Holger Teutsch wrote:
> > > > On Mon, 2011-04-04 at 15:24 +0200, Andrew Beekhof wrote:
> > > [...]
> > > > 
> > > > crm_resource --move-off --resource myClone --node C
> > > >    -> I want the instance moved off C, regardless where it is moved on
> > > 
> > > What is the difference between move-off and unmigrate (-U)?
> > 
> > --move-off -> create a constraint that a resource should *not* run on
> > the specific node (partly as before --move without --node)
> > 
> > -U: zap all migration constraints (as before) 
> 
> Ah, right, sorry, wanted to ask about the difference between
> move-off and move. The description looks the same as for move. Is
> it that in this case it is for clones so crm_resource needs an
> extra node parameter? You wrote in the doc:
> 
> 	+Migrate a resource (-instance for clones/masters) off the specified node.
> 
> The '-instance' looks somewhat funny. Why not say "Move/migrate a
> clone or master/slave instance away from the specified node"?

Moving away works for all kinds of resources so the text now looks like:

diff -r b4f456380f60 doc/crm_cli.txt
--- a/doc/crm_cli.txt	Thu Mar 17 09:41:25 2011 +0100
+++ b/doc/crm_cli.txt	Tue Apr 05 13:08:10 2011 +0200
@@ -818,10 +818,25 @@
 running on the current node. Additionally, you may specify a
 lifetime for the constraint---once it expires, the location
 constraint will no longer be active.
+For a master resource specify <rsc>:master to move the master role.
 
 Usage:
 ...............
-        migrate <rsc> [<node>] [<lifetime>] [force]
+        migrate <rsc>[:master] [<node>] [<lifetime>] [force]
+...............
+
+[[cmdhelp_resource_migrateoff,migrate a resource off the specified
node]]
+==== `migrateoff` (`moveoff`)
+
+Migrate a resource away from the specified node. 
+The resource is migrated by creating a constraint which prevents it
from
+running on the specified node. Additionally, you may specify a
+lifetime for the constraint---once it expires, the location
+constraint will no longer be active.
+
+Usage:
+...............
+        migrateoff <rsc> <node> [<lifetime>] [force]
 ...............
 
 [[cmdhelp_resource_unmigrate,unmigrate a resource to another node]]

> 
> I must say that I still find all this quite confusing, i.e. now
> we have "move", "unmove", and "move-off", but it's probably just me :)

Think of "move" == "move-to" then it is simpler 8-)

... keeping in mind that for backward compatibility

crm_resource --move --resource myResource

is equivalent

crm_resource --move-off --resource myResource --node $(current node)

But as there is no "current node" for clones / masters the old
implementation did some random movements...

Regards
Holger

> 
> Cheers,
> 
> Dejan
>