How will IPFailover of anXSAN client affect mounted volumes?

Woodgie · partially protected Joined: 10 Jun 2010 Posts: 8

I just had a thought.

If I have XSAN in a 4 server setup - PrimaryMDC, SecondaryMDC and 2 APF servers set with IP Failover so if the primary AFP server goes pop the secondary AFP server can take over - how does XSAN deal with one of its clients (the secondary AFP server) suddenly having an IP personality change?

I'm envisaging the set up where the secondary AFP server is sitting there with the XSAN volume mounted and the sharepoints set up as per the primary but with AFP turned off. When the primary goes pop the secondary inherits its IP address and a script kicks AFP into play and the clients should notice minimal disruption (a couple of minutes at the most).

Should I set the XSAN volume mounting as a script too? I'm just sure that the PMDC will throw its toys out of the pram if a client's IP address changes when a volume is mounted.

Thanks,
William

abstractrude · Xsan Master Joined: 13 Mar 2008 Posts: 881

i had a situation where someone wanted to do this, instead I load balanced with round robin. so afp was good to go.

Woodgie · partially protected Joined: 10 Jun 2010 Posts: 8

abstractrude · Xsan Master Joined: 13 Mar 2008 Posts: 881

you just round robin the connections. I think i used ultra monkey. so when a connection comes into the load balancer it forwards to 1 of 3 afp servers, if one of those afp servers goes down the load balancer stops forwarding. its literally been 5 years since i did it but it can work.

Woodgie · partially protected Joined: 10 Jun 2010 Posts: 8

abstractrude · Xsan Master Joined: 13 Mar 2008 Posts: 881

xsan has file locking, which was the backend. but it was for home directories so i was fortunate to not have to worry about that due to the nature of the service. i really think this ipfailover thing can work. as long as you dont do it on the controllers. ipfailover will take the service stuff i believe, haven't touched it in years.

morphenine · Xsan Master Joined: 22 Dec 2008 Posts: 126

Interesting, I hadn't thought of this. Its sorta like the AFP version of Cisco's HSRP. I like it!

Maybe try installing another Ethernet card into the server. Then you can have the primary IP (for management and OD and other Xsan-ish stuff), the Metadata, and the "floating" interface that users point at.
We've done several servers with 3+ IP addresses and it works fine sharing out AFP. This way, Xsan isn't using the IP address that gets re-assigned and it stays happy when theres a sudden change.

I suppose you could also use intelligent routing and create a Virtual IP that routes to the other if one is no longer available. Either way seems viable.