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R: Cluster mode - Market vs field
I agree with you and Todd but I've another point of view.
I know very well other competitor (really ones) in the field of 'cluster' such as Isilon (and this one considers a real competitor only NetApp).
For Isilon and such companies cluster mean over all HPC, parallel f/s, single name spaces, grid computing, they mean also to share network and other resources in a scale-out point of view.

I think for that reason that to propose CM to justify a 'never poweroff', 'move a single vol without interruption' and so on is a very limited vision maybe because in the scale-out sharing of resource the NetApp disk ownership is a constraint? Or more realistically because to speak of CM thinking to 2200 systems could be a nonsense (customer with limited budget and needs..


-----Messaggio originale-----
Da: Bennett Todd [] Per conto di Bennett Todd
Inviato: domenica 17 giugno 2012 18:27
A: Blackmor, Chris; Milazzo Giacomo
Oggetto: Re: Cluster mode - Market vs field

On Jun 17, 2012 12:08 PM, "Blackmor, Chris" <> wrote:
> With all the missteps NA has had getting C-mode out the door I don't think they can really push it on anyone. Remember Auspex 1.8.  Where's Auspex now?

A very fond memory, if triste; the months that felt like years that I spent trying to master the art of handholding the recovery of lock state after failover, and appreciating the cleverness of the multicast tricks and nfs protocol.shortcuts, taught me lessons about how NFS really works (when it does) that will last me.

H-A is great when it works, but I've rarely seen implementations that aren't seriously lower availability than the single-point-of-failure system they try to replace.

Though I think what did for Auspex wasn't their ambitious H-A, it was NetApp's ability to cling tenatiously to the Juggernaut as Moore's Law drove costs of processing, memory, and bandwidth down, and down, and ever down.

Toasters mailing list
R: Cluster mode - Market vs field [ In reply to ]
I really appreciate this contribution.

Da: [] Per conto di Bohemen, Anton van
Inviato: lunedì 18 giugno 2012 11:56
Oggetto: RE: Cluster mode - Market vs field

Well, to be honest, I think it is time to (at least) start thinking about moving to cluster mode. A FAS2220 is a bit on the positive side as you can’t do SAN with it in C-Mode, but a 2240 can, so then you are fine. I’ve been testing quite extensive with the simulator and it actually works fine. A bit to my surprise as well I must admit, I was just as skeptical as you all. The concepts are great and the VServer virtualization layer is a great addition to the WAFL storage virtualization layer. VServers work so much better than vFilers and with c-mode you get all the scalability advantages you need.

So, I’m not surprised all the commercial people at NetApp and partners are pushing to C-Mode. If you have a technology refresh in a few years, you should definitely consider it. If you have one this year, I’m not really sure yet. Not because not all features are supported in c-mode (yet), but right now it is quite a steep learning curve if you’re used to 7-mode. You need to re-think most of your storage setup but once you do, I think c-mode will fit a lot of environments.

Bottom line: start reading and testing, I think c-mode actually is a good product.



From:<> []<mailto:[]> On Behalf Of Blackmor, Chris
Sent: zondag 17 juni 2012 17:45
To: Milazzo Giacomo
Subject: Re: Cluster mode - Market vs field

They can say that all they want but I think NA has had way too many missteps with C-mode to be pushing it down anyone's

Sent from my iPhone

On Jun 17, 2012, at 10:24 AM, "Milazzo Giacomo" <<>> wrote:
Hi all,

I’ve recently attended an official event where people from NetApp in few words said:

“DOT 8 7-mode has done its time, it’s over, it has been a great os but It’s now time to move and push DOT 8 Cluster Mode, everytime, everywhere…” and this also if with a simple two node HA system, including 2220!

What do you think about? Also let us assume that cluster mode can (I add ‘theoretically’) do all what 7 mode does, don’t you think that is quite premature to trumpet this out?


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R: Cluster mode - Market vs field [ In reply to ]
I'm really glad that my questions started a so interesting discussion.
And of course I'm also glad to read that speaking about "cluster mode" has to be based on a minimum of a two nodes (four heads) because it could be a really nonsense to speak about GNS, grid storage, HPC and so on in a "small" environment where budget and needs are no more that a 2220 with 10k SAS disks...
Isilon (that I know) has also be cited as the really competitor to compare with - and the same opinion about NetApp comes from Isilon, part of but not from EMC of course :-).
But just because I know a lot of things about Isilon technology (from field) I still continue to think that disk ownership can be the real constraint from a pure performance (in HPC word) point of view.

Thank you everybody

-----Messaggio originale-----
Da: [] Per conto di Kennedy, Jeffrey
Inviato: mercoledì 20 giugno 2012 00:47
A: Darren Sykes; Angelescu, Silviu
Cc: Michael Bergman; Toasters
Oggetto: RE: Cluster mode - Market vs field

With the access methods available today (either RRDNS or the onboard load balancing) a client can land on any lif regardless of the intended access target. pNFS fixes that, but there's no telling how far away that really is.

We see more traffic on the intercluster network than on the data network, regularly. Granted, we move volumes all the time (being able to load balance and expand capacity at will without 7 mode restraints is fantastic) and as we add nodes that traffic increases, but even without that there is and will be a significant amount of cluster traffic that is due to non-local lif's.

If your need is truly very high performance, cluster mode is not for you, at least not now. For marginally high performance and lower it performs well enough. If you are able/willing to trade some of the features of 7 mode (ok, let's be honest, it's quite a few features still) for the primary benefits of CM, you are unlikely to be disappointed. For the data set we put on CM we can do without those features, for now, but the benefits of the namespace and transparent volume migrations for capacity or load balancing is a major benefit. Enough to outweigh all the features we've yet to see on CM.

Jeff Kennedy
Qualcomm, Incorporated
QCT Engineering Compute

-----Original Message-----
From: [] On Behalf Of Darren Sykes
Sent: Tuesday, June 19, 2012 12:57 PM
To: Angelescu, Silviu
Cc: Michael Bergman; Toasters
Subject: Re: Cluster mode - Market vs field

I'll back up what has already been said - there's absolutely no guarantee you'll access a local dblade without pnfs.

The other thing to consider is infinite volumes - with no nfs4 support, by nature you'll use the cluster network most of the time.

There's no need for a sim - we're running 8.1p1 in our live environment, and will run 8.1.1RC in dev.

Sent from my iPhone

On 19 Jun 2012, at 18:33, "Angelescu, Silviu" <> wrote:

> Someone mentioned below "With C-mode there's "local" and "remote"
> array access". Actually, "remote" access would never happen when LIFs
> are configured on each node (which is the recommended best practice
> configuration). The only case when you'd get remote traffic thru the
> interconnect 10GigE network is when you need to shutdown a node for an
> upgrade for example, or when you move a volume to a node where you
> don't have a LIF configured (but you could also move the LIF along
> with the volume or just create a new LIF on the destination node and
> that would provide a direct path to the new destination node for the
> volume; one LIF on each node is the bottom line recommended best practice).
> Regarding the "performance impact" of cluster-mode, you may want to
> check the latest SPC-1 benchmark results with FAS 6240 in cluster-mode:
> /A001
> 15_NetApp_FAS6240-cluster/a00115_NetApp_FAS6240-cluster_SPC-1_executiv
> e-sum
> mary.pdf
> Regarding the new CLI, I really like it. Conceptually, it's similar to
> Cisco's CLI (contextual commands, contextual help, tab to complete the
> command or get help). The tab and help features are really great.
> I suggest looking up the data about ONTAP 8.1 cluster-mode and try it out.
> Perhaps, download the cluster-mode vSim first and try it on your laptop.
> ONTAP 8.1 cluster-mode is not my "grandpa's ONTAP cluster-mode" system
> anymore. There's a lot of goodness to it now and it's stable and
> really easy to work with. You could check the Data ONTAP Cluster-Mode
> Administration course begin taught by NetApp training partners to test
> drive it further if you wish.
> Cheers,
> Sil Angelescu
> On 6/19/12 12:57 PM, "Darren Sykes" <> wrote:
>> I was trying to be diplomatic, seems Michael has lowered the bar on
>> that count :)
>> I agree with you both. I was very concerned about the latency when
>> accessing remote dblades in our environment since we have lots of
>> very small files where the difference is highlighted. There was
>> supposed to be significant improvements in 8.1 - I should really
>> re-run the tests to prove that.
>> At the moment we attempt to work around the problem by tracking where
>> volumes live and mounting the nblade local to the dblade. Admittedly,
>> that's not the most elegant solution and there is a lag as volumes move.
>> I wonder how that latency will impact the performance of infinite
>> volumes in 8.1C and beyond?
>> We also have Isilons and their infiniband backend proved extremely
>> good in reducing the overhead of access remote nodes. Not that they
>> don't have other performance gotchas.
>> Darren
>> -----Original Message-----
>> From:
>> [] On Behalf Of Blake Golliher
>> Sent: 19 June 2012 17:43
>> To: Michael Bergman
>> Cc: Toasters
>> Subject: Re: Cluster mode - Market vs field
>> In fairness, I used C-Mode at my last place and I can say a few things.
>> - the new cli isn't has hard to pick up as you might think. I feel
>> within a 3 weeks or a month I was pretty comfortable with it.
>> - there is a back way into the old ontap cli (it's not exactly the
>> same, but close) for some debugging things.
>> - the latency isn't nearly as bad as you might think. We had Nexus
>> 5k's and many 10g links, and worked pretty smoothly.
>> - While stability wasn't 100%, the failovers worked as expected and
>> filesystems never stopped being served. This was 8.0 C-Mode
>> - Moving data between cfo pairs is slick and awesome. Highly
>> recommend 64bit aggrs.
>> All that said, I don't think a C-Mode cluster should be pushed unless
>> 4 nodes are in it, two cfo pairs is what every c-mode cluster should
>> start as. Two nodes doesn't make a heck of a lot of sense. I now
>> live in a sea of Isilon and comparing and contrasting the two
>> platforms is pretty interesting.
>> Hope that helps,
>> -Blake
>> On Tue, Jun 19, 2012 at 8:40 AM, Michael Bergman
>> <> wrote:
>>> Darren Sykes wrote:
>>>> While I wouldn't disagree that it's a good product, having run GX,
>>>> then 8.0C then 8.1C I'd argue that in a 2 node configuration C mode
>>>> would be less reliable with little benefit over 7 mode at this point in time.
>>> Quite... Functionality wise, C-Mode isn't finished yet either,
>>> there's quite some work for NTAP to do still. And it's not stable
>>> in the proper sense of the word -- 8.1 7-mode isn't stable yet
>>> either.
>>>> In fact, I'd probably wager that there will be a minimal
>>>> performance degradation too.
>>> There is. But it's not minimal, not in any sense of the word. With
>>> C-mode there's "local" and "remote" array access (the back-ends
>>> below the heads so to speak) and the additional latency induced by
>>> the cluster network is big.
>>> Really big. In use cases where you need to be down at 1 ms avg
>>> internal latency for NFS (with the help of PAM-II etc), for a fair
>>> NFSops load point, you can just forget about C-Mode yet. *Maybe*
>>> some time in the future, maybe it can be polished until 8.2Px or
>>> 8.2.1 is out... We'll see.
>>>> Less speed and reliability is a hard sell and that's before you
>>>> even think about how difficult it'd be to move to C mode without
>>>> buying more hardware.
>>> Somehow "moving" to C-Mode without deploying a whole new system from
>>> scratch is unthinkable from there I stand. But of course it depends
>>> on the use case and other details.
>>> I'd argue that at this point at least and for the next 24 months
>>> C-mode is pretty much like deploying a completely new (from a
>>> different vendor) storage system at your site in your environment,
>>> effectively potentiually doubling the complexity to handle for your
>>> storage ops ppl. Remember the CLI is completely different as well
>>> (for the large group of us who need/want to use that a lot, suppose
>>> a no of customers use the Web GUI way of controlling Filers to 100%)
>>> /M
>>> _______________________________________________
>>> Toasters mailing list
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