Selective LUN Mapping on ONTAP 8.3

We have a customer with a pretty kick-ass ONTAP environment that we built up last year – dual sites, each with 2x FAS8040 HA pairs in a cluster. This year we added an HA pair of AFF8080s with 48 x 3.84TB SSDs to each site, which included an upgrade to ONTAP 8.3.2.

We’re in the process of migrating from older FAS3270s with ONTAP 8.2 for these guys – we did a bunch of migrations last year, and we started again this year. Depending on application, workloads, etc we have a number of different methods for migration, but we got caught out last week with some LUN migrations.

Turns out there is a new features in ONTAP 8.3, which is turned on by default for new and migrated LUNs – selected LUN mapping. SLM reduces host failover time by only announcing paths from the HA pair hosting the LUN. But it’s only turned on for new LUNs – existing ones still show all 12 paths (2 per node). This is a bit of an odd choice to my thinking – I think it should optional if the system is already in production.

So our excellent tech working on the project, thinking it was a bug, called NetApp Support – and spent way too long being told to upgrade HUK, DSM and MPIO. Needless to say.. this didn’t work. Kinda disappointing. I’m told there’s a magic phrase you can use – “I feel this call isn’t progressing fast enough, can you please transfer me to the duty manager?”. Has this ever worked for you? Let me know in the comments 😉