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XMS communication to storage controllers
In a multi Xbrick XtremIO Cluster, how does the xms push the control configs to storage controllers? Does it randomly pick one SC to do the config or it picks SCs in a RR fashion?
scotthoward
64 Posts
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March 6th, 2016 10:00
The XMS talks to a component on the storage controllers called the "System Manager", or SYM for short.
The SYM only ever runs on a single storage controller at a time, but can move between the two storage controllers in the first brick in the array, so if a storage controller fails for any reason, the SYM will nearly immediately move to the other SC so that the XMS can still communicate with it.
Specifically for configuration events, the SYM can then push details to all of the other storage controllers in the array, which occurs over the InfiniBand backplane of the array.
Cherry251
28 Posts
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March 7th, 2016 10:00
Scott,
Does the SYM always run on one of the SCs in the first Xbrick only? What about the other Xbricks?
Kumar_A
727 Posts
1
March 7th, 2016 13:00
Yes, the SYM will run on one of the two storage controllers in the first X-Brick. If both the controllers are not available at the same time for any reason, the whole array is down and there is no point in keeping the SYM module up and running.
Even though the SYM module is running in the first X-Brick only, it knows how to contact other clustering software module running in each controller of every other X-Brick in the array.