MSL2024, p421 controller, Win2012, device SAS addresses repeatedly change by themselves!

[Neal Howard]

I've got a 2xLTO5 MSL2024 library connected to a p421 smartarray card in a Proliant DL380e Gen8 running Windows Server 2012 Standard edition. About once every 7-10 days all of a sudden, all the SAS device addresses are spontaneously changing by themselves to new numbers... which causes my backup software to fail because suddenly the hardware can no longer be found at the addresses configured into the backup software. In Windows Device Manager the devices are all still present, but have diffeent SAS address numbers than they formerly had.

Anybody have an idea of what could be causing this?

This system was installed and first set up in January and ran fine with no issues untill mid-March, then the SAS addresses of the hardware started "squirming around" about once every week or thereabouts.

For instance last week, when I rescanned the hardware and deleted/re-added the devices in my Netvault backup configs, the Library itself was located at SAS address 2.2.3.1, with Drive1 at 2.2.3.0 and Drive2 at 2.2.4.0.

Now today I find that the Library is now detected at 2.2.1.1, Drive1 is 2.2.1.0 and Drive2 is 2.2.2.0.

Previously a few weeks ago, the addresses had been yet a different set of numbers.

The system has had no reboots, nobody else has been monkeying with it or anything. These changes are happening spontaneously, automatically, and without warning or notice all the while the operating system has been up and running continuously 24x7.

Is something in Windows 2012 doing something to the p421 card and cause it to re-assign the addresses?

Is the firmware in the p421 card doing this all by itself?

Or is something in the MSL2024 Tape Library doing it?

[StephenWagner7]

Have you updated the drives and library to the latest firmware?

[madscientist159]

This sounds like it might be related to my post here:
http://h30499.www3.hp.com/t5/Tape-Libraries-and-Drives/Ultirum-3000-Spontaneous-Hard-Resets/td-p/6471338

Are you using Ultrium 3000 drives in the library? Does the address change tend to occur when the drives are in use?