I just want to confirm. Will it be disruptive to active CIFS sessions if I failover/migrate the LIF?
TR 4100 covers this really well.. a really nice reference. See page 6. a LIF migrate and vol move are non-disruptive to SMB 2 and SMB 3. lif migrate is disruptive only if SMB 1.0. An aggregate relocate (from takeover/giveback or by command) is disruptive to SMB 2.0 though but not 3.0 with CA.
Judging by the fact that NetApp created a solution to make sure SMB1 will still work, I guess NetApp left it to the Windows environment to decide if they will eliminate SMB1 or not. Security engineers may not like this. lol
TR 4100 covers this really well.. a really nice reference. See page 6.
Page 7 is more interesting as it details conditions when LIF migration is really non-disruptive. It seems that SMB 2 or 3 alone does not gurantee it; there are situations when session may be lost.
I wonder if Windows is using durable handles by default (and in which versions). I could not find any explanation, but then I am not really Windows guy.
This is what it says in page 7
In order for the LIF migrate to be nondisruptive, the SMB 2.x and 3.0 connections must establish and maintain a durable handle to the open file handle. When a LIF is migrated between nodes, those SMB 2.x and 3.0 clients with durable handle connections have their handles put into a temporary “disconnected” state. In order for the file handles to remain open, the client applications need to reconnect to the “disconnected” file handles
All this tells me is that I cannot guarantee to my managers that there will be no outage in CIFS. You are right, I am not sure how to identify that "durable handle".