SIOControlFlag1 flipflopping between values on one host at a time

[sjwk]

I'm seeing a curious thing in my vmkernel.log files.  It doesn't appear to be causing me any problems besides taking up log space and potentially making other messages harder to spot amongst the noise, but just want to be sure that it isn't a precursor to another issue.

On one of my hosts, I'm seeing frequent log messages every minute or so (appears to be 66 seconds give or take, with an occasional skip) with SIOControlFlag1 flipflopping back and forth between a value and zero.  Eventually it will stop on that host, but at the same time will start doing the same on a different host, yet no VMs appear to have migrated between them so don't think the messages are tied to a particular VM.  In all cases, the value is the process ID of /sbin/sdrsInjector.  None of my datastores have Storage IO Control enabled.

e.g.:

2016-03-01T11:12:05.649Z cpu0:34055)Config: 346: "SIOControlFlag1" = 0, Old Value: 34055, (Status: 0x0)

2016-03-01T11:13:11.522Z cpu0:34055)Config: 346: "SIOControlFlag1" = 34055, Old Value: 0, (Status: 0x0)

2016-03-01T11:14:17.742Z cpu8:34055)Config: 346: "SIOControlFlag1" = 0, Old Value: 34055, (Status: 0x0)

2016-03-01T11:15:23.595Z cpu2:34055)Config: 346: "SIOControlFlag1" = 34055, Old Value: 0, (Status: 0x0)

2016-03-01T11:16:29.796Z cpu6:34055)Config: 346: "SIOControlFlag1" = 0, Old Value: 34055, (Status: 0x0)

2016-03-01T11:17:35.643Z cpu10:34055)Config: 346: "SIOControlFlag1" = 34055, Old Value: 0, (Status: 0x0)

2016-03-01T11:18:41.838Z cpu4:34055)Config: 346: "SIOControlFlag1" = 0, Old Value: 34055, (Status: 0x0)

2016-03-01T11:19:47.696Z cpu10:34055)Config: 346: "SIOControlFlag1" = 34055, Old Value: 0, (Status: 0x0)

2016-03-01T11:20:53.878Z cpu8:34055)Config: 346: "SIOControlFlag1" = 0, Old Value: 34055, (Status: 0x0)

2016-03-01T11:21:59.748Z cpu5:34055)Config: 346: "SIOControlFlag1" = 34055, Old Value: 0, (Status: 0x0)

Anyone seen this before and can explain what's causing this, or know whether it indicates an issue or if it's normal behaviour?

[stacycarter]

sjwk​ Did you ever find an explanation for this?  I'm seeing the same thing in the logs of our ESXi 6.0 U3b hosts, and SIOC is not enabled.

[sjwk]

Hi stacycarter​,

Just checked the logs and still going on.  I'd had a vague feeling I'd pinned it on some issues we were having with Pernixdata acceleration and the servers' SATA controllers.  But I can't find any reference to it in my email discussions with them, and that's long fixed while I'm still getting the log entries so obviously not!  Likewise rebooting servers and installing updates also not fixed it.