Keith edited out a few questions in his response so I just wanted to go back to your original query and make sure I covered all the questions.
alexei@cimedia.com wrote:
According to the white paper http://www.netapp.com/technology/level3/1004.html, in a clustered failover (CF) setup 2 filers would be attached to the same fc loop, 1 filer to the A port and 1 to the B port (to determine who is "master" for that set of disks).
We think of it as owner rather than master, but I guess its the same thing.
Now, I take this to mean that on any given loop, only 1 filer can be master for that loop. Based on this assumption, how does this alter the max shelves per filer?
Max doesn't change, but you should also not that on any given loop there is one and only one FC-AL adapter (controller). We don't allow two controllers on the same loop. We make use of the dual ported nature of FC-AL disks to insure there are two independent paths to the disk so that if a takeover occurs there is a completely different path used to get at the partner's disks.
That is, on a f740 I can have 2 loops (based on the 8 shelves per loop guideline and 16 shelves per filer on a 740). If this f740 and another f740 were part of the same CF setup and both filers were "active", would I be limited to a single loop of active shelves on each filer? Or would I be able to have 4 loops, 2 active and 2 in standby (ie: my partners shelves)?
Still limited to two loops.
Or does the 8 shelves per loop guideline not apply to the CF setup?
It still applies, sorry.
I just looked through the f700 hardware guide as well as the ONTAP 5.2 sys admin guide (thanks for having that up). The chapter on CF is good. Definitely. Ok, so the hardware guide says that a f740 and an f760 can both only have 112 fcal drives, 2 fcal loops max.
Oh my goodness. Actually that was a mistake [blush], we usually put up both the release binary and the docs at the same time. But now that you mention it, perhaps its a good idea to get the docs up there early. Since we have to finish them ahead of the binary because of the cycle time for printing we could make it a policy to get the docs up earlier. I'll pass this suggestion on to the Tech Pubs group. Thanks for the idea.
How does the 760 then do 1.4TB of storage and the 740 960GB? Seems there are 56 or so drives missing.... another loop?
Yes, the plan is to allow F760 to go to 3 loops, 4 with Cluster.
So, my bottom line question is: in a CF setup with 2 f740's, what is the maximum *useable* storage space I will have (combined)?
I think I covered this in my last message
Also, why does a f630 get to have 3 fcal loops?
We actually had F630s running 168 disks before we even had the F700 series hardware running. Its just a matter of timing.
Boy, I am just full of questions tonight...
Thanks.
Alexei