From 0bfbb3e8d1d31e92ad01b53f317abedd868eabab Mon Sep 17 00:00:00 2001 From: Iustin Pop Date: Tue, 13 Oct 2009 12:10:29 +0200 Subject: [PATCH] Update the hbal manpage w.r.t. job execution Signed-off-by: Iustin Pop Reviewed-by: Michael Hanselmann --- hbal.1 | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/hbal.1 b/hbal.1 index 1f8149c..0f24896 100644 --- a/hbal.1 +++ b/hbal.1 @@ -15,7 +15,7 @@ hbal \- Cluster balancer for Ganeti Backend options: .BI "[ -m " cluster " ]" | -.BI "[ -L[" path "]]" +.BI "[ -L[" path "] [-X]]" | .BI "[ -n " nodes-file " ]" .BI "[ -i " instances-file " ]" @@ -175,6 +175,20 @@ The options that can be passed to the program are as follows: .B -C, --print-commands Print the command list at the end of the run. Without this, the program will only show a shorter, but cryptic output. + +Note that the moves list will be split into independent steps, called +"jobsets", but only for visual inspection, not for actually +parallelisation. It is not possible to parallelise these directly when +executed via "gnt-instance" commands, since a compound command +(e.g. failover and replace-disks) must be executed serially. Parallel +execution is only possible when using the Luxi backend and the +\fI-L\fR option. + +The algorithm for splitting the moves into jobsets is by accumulating +moves until the next move is touching nodes already touched by the +current moves; this means we can't execute in parallel (due to +resource allocation in Ganeti) and thus we start a new jobset. + .TP .B -p, --print-nodes Prints the before and after node status, in a format designed to allow @@ -340,6 +354,17 @@ socket on which the master daemon listens; otherwise, the default path used by ganeti when installed with "--localstatedir=/var" is used. .TP +.B "-X" +When using the Luxi backend, hbal can also execute the given +commands. The execution method is to execute the individual jobsets +(see the \fI-C\fR option for details) in separate stages, aborting if +at any time a jobset doesn't have all jobs successful. Each step in +the balancing solution will be translated into exactly one Ganeti job +(having between one and three OpCodes), and all the steps in a jobset +will be executed in parallel. The jobsets themselves are executed +serially. + +.TP .BI "-l" N ", --max-length=" N Restrict the solution to this length. This can be used for example to automate the execution of the balancing. -- 1.7.10.4