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1 ajeffco commented Permalink

Is IBM planning on releasing any "live monitoring" tools for the SVC in general, and performance specifically? <div>&nbsp;</div> While performance is a subjective issue, it would still be nice to see real time what the SVC nodes themselves are doing. <div>&nbsp;</div> Al

2 orbist commented Permalink

Hi Al, <div>&nbsp;</div> At present, SVC produces so much performance data that its generally post processed by something like TPC, and of course we do supply the XML details so many users have grown their own tools. <div>&nbsp;</div> But the request is quite common and is in the 'futures' bucket - I personally would like to see a dashboard style high level summary at least - there is nothing concrete in plan at present however. <div>&nbsp;</div> Barry

3 Kuno commented Permalink

Hello! <br /> I would like to know if it's possible using SVC in two sites implement a solution that if primary site fails, the storage at the other site can be running. In other words automatic failover and almost zero downtime. is it possible? If Yes. How can we avoid the split brain problem? The problem generated when the communication is broken and each individual site thinks that the other site has gone offline. <div>&nbsp;</div> Thanks!

4 orbist commented Permalink

Kuno, <div>&nbsp;</div> Yes we can. See my post here https://www.ibm.com/developerworks/mydeveloperworks/blogs/storagevirtualization/entry/split_cluster?lang=en_us <div>&nbsp;</div> The split brain is solved easily via the same method SVC itself uses to determine cluster splits. The "lease" that is renewed around the cluster will fail very quickly if a node has gone awol and the first "half" that gains a lock on the quorum disk gets to continue. This is why the quorum disks must be in a third power domain when using a split cluster configuration, so that a power loss at either site does not take out the quorum disks at the same time. <div>&nbsp;</div> We have a large number of customers running this HA solution, and a growing number that are combining this with GlobalMirror to provide a relatively local HA solution and a third site for DR. <div>&nbsp;</div> Barry

5 Kuno commented Permalink

Hello Barry! <br /> Thank you! <br /> Do you know where I can find more details about this implementation? <br /> I'm not sure if the new Redbook about SVC covers this kind of solution. <br /> I'm from Brazil and I have a customer here that wants a scenario like this. Unfortunately it's not commom here to have SVC, Ordinary Storage arrays and 3rd site. <div>&nbsp;</div> <div>&nbsp;</div>

6 orbist commented Permalink

Kuno, <br /> The details are in the SVC configuration users guide, or online in the infocenter : <br /> http://publib.boulder.ibm.com/infocenter/svcic/v3r1m0/index.jsp?topic=/com.ibm.storage.svc.console.doc/svc_hasplitclusters_4ru96h.html <br /> Cheers, Barry

7 Han_Solo commented Permalink

Barry, maybe this is a 'see your sales rep' question. <div>&nbsp;</div> But, I was asked this the other day by one of my procurement people. <div>&nbsp;</div> If you purchase a SVC EE, and its licensed up to 60 disks I believe. <div>&nbsp;</div> If you later convert that to regular SVC does the licenses convert on a 'capacity basis' or is there some other formula at work there? <div>&nbsp;</div> Eg, if I had 60 300GB disks, would that be converted to 1800GB of regular SVC capacity based licenses? <div>&nbsp;</div> Just curious. I belive that SVC EE is a great solution, and have been recommending SVC EE to some internal customers and this 'what would happen if we ever exceeded the EE requirements'. <div>&nbsp;</div> Thanks. <br />

8 DiegoKesselman commented Permalink

Barry, <div>&nbsp;</div> is IBM planning to add some kind of embed SVC or SVC EE in products like XIV or DS5000 or DS8000 ?

9 uhaas commented Permalink

Barry, <div>&nbsp;</div> First, the Mdisk 2 TB limit is causing real pain. I'm constantly working around it and was hoping 5.1 would address this, but only Vdisks got supported. <div>&nbsp;</div> Are there plans for de-dup in the SVC? This would be a smash hit, give current storage climate. I understand it wouldn't be for every vdisk out there, but would be nice for some. It shouldn't be impossible, given the storage virtualization technology is already present. <div>&nbsp;</div> Urban

10 orbist commented Permalink

Sorry folks been in Germany at an SVC User Group meeting last week and been catching up... <div>&nbsp;</div> Han : <div>&nbsp;</div> SVC EE has license up to 250 disks now (and higher if needed) However you often find by that time that it makes more economic sense to switch to the capacity based license. So yes, you can switch to the capacity license, however remember its mdisk capacity, so 7+P (you don't pay for the P) <div>&nbsp;</div> Barry <br />

11 orbist commented Permalink

Diego, <div>&nbsp;</div> Future plans are generally held under IBM Confidential NDA's - therefore I cannot discuss future deployment of the SVC code base - if you want to learn more about our roadmap, contact your sales rep / account team and we can get the necessary NDA's setup. <div>&nbsp;</div> Barry

12 orbist commented Permalink

uhass, <div>&nbsp;</div> 2TB, yeah its is understood, with everything else we squeezed in to 5.1 (some very late in the development cycle - like the SSD support) some things had to push out. Later this year, &gt; 2TB shouldn't be an issue :) At the moment, the only solution is to create multiple mdisk per array, but if you do, keep an eye on the performance as SVC may try to drive too much I/O to such mdisks. <div>&nbsp;</div> As for dedupe, its always been an idea, and some of the team were closely involved with the Diligent acquisition, so we have a good understanding of the IBM products. The discussion over dedupe of online data vs data at rest (archive) is usually quite heated, the biggest issue is the performance impact / CPU overhead in looking for dedupe "similarities" and of course the potential for I/O generation when reading back lots of small blocks. But SSD are really good at small block reads... maybe moving forward (IMO) we will see more online dedupe as SSD and processing power increases. Thats just my opinion, and again discussing future product roadmaps on this blog isn't possible. <div>&nbsp;</div> Barry

13 jfessler commented Permalink

I have a customer who purchased the SVC before the EE was announced. It currently has only 14 disk and is expanding to 32 supporting a pSeries. None of the Microsoft servers use the SVC because it is too expensive to increase the license per TB. Is there any way to change this customers license to EE so they can utilize it for these systems?