Looking to Buy a SAN
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This would be for our VMs. We mostly have application servers and SQL database servers. We have 5 new hosts for VMware to connect up to it.
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@ScottyBoy said in Looking to Buy a SAN:
This would be for our VMs. We mostly have application servers and SQL database servers. We have 5 new hosts for VMware to connect up to it.
VMs are specifically a time when a SAN really never applies. And especially highly critical workloads like databases. This is, by far, the absolute extreme of "a SAN should never enter the conversation for this." This is the textbook example worst workload for SAN.
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This issue goes way beyond storage, but involves overall system architecture basics. Using a SAN with virtualization hosts like this is called an IPOD or an "Inverted Pyramid of Doom" and is considered the most fundamental system design failure that you can have. (This goes great with my engineering topic from two days ago about how systems are often engineered / setup by people who aren't familiar with the basics, then handed to experienced people to manage who are stuck with those decisions.)
We covered this at MangoCon 1 four years ago, here is the video...
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Here is an article helping to explain the Inverted Pyramid of Doom.
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@scottalanmiller said in Looking to Buy a SAN:
@ScottyBoy said in Looking to Buy a SAN:
This would be for our VMs. We mostly have application servers and SQL database servers. We have 5 new hosts for VMware to connect up to it.
VMs are specifically a time when a SAN really never applies. And especially highly critical workloads like databases. This is, by far, the absolute extreme of "a SAN should never enter the conversation for this." This is the textbook example worst workload for SAN.
What use cases do you recommend SANs for?
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@ScottyBoy said in Looking to Buy a SAN:
What use cases do you recommend SANs for?
Almost none, but here is an article (from me) detailing when they DO make sense: https://smbitjournal.com/2013/06/when-to-consider-a-san/
But to break it down, SANs are slow, risky, and complex. Those are the negatives. Pretty big ones. Their advantages are that they are flexible. That's really it.
They fall into a pattern known as a "never until you have to". That means, you never want a SAN, unless you have to have a SAN - that's because there are times when no other technology CAN work, but a SAN will. But if any other technology can work, then a SAN shouldn't be considered. This makes it easy, because you simple never consider a SAN at all, you never discuss it, until you are in a situation where there is no other choice, then you get stuck with it. And in that case, it's awesome because it does what nothing else can do and the expensive, complex or risky simply don't matter because the alternative is simply failure.
The standard pattern for success with virtualization for the past 12+ years is hyperconvergence and it was a pretty standard pattern prior to that. For virtualization essentially your storage should never be remote from your compute. Storage and compute use almost no overlapping system resources, so separating them wastes a ton of money and performance, and having multiple points of failure when you only need one means creating huge complexity and risks for no benefit.
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When you DO need a SAN, it'll generally fall into one of two cases:
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The big one, production. You have a need for production level storage and nothing but a SAN will work (never a case when database and/or virtualization is involved, so this cannot apply to your situation realistically.) When in production, you need SAN that is insanely reliable and this means full redundancy and that means insanely expensive, high end systems like EMC Clariion or HPE 3PAR (and I've had both of those fail, too, but not often.) You have to have complete redundancy meaning two SANs, minimum, to even call it a risky production system.
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The small one, not production. In non-production environments where you need bulk flexible storage and you simply don't care (much) about performance, uptime, or dataloss then you can consider more affordable SAN options like EqualLogic which simply isn't realiable enough to qualify for production usage by any reasonable standard, but in a lab or something, would be potentially fine.
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The HPE engineer we talked said that's not really the case with them anymore, and they are designed much better these days to handle fault issues.
Aside from that we already have bought 5 new hosts (1U hosts with just SD cards for VMware)
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@ScottyBoy said in Looking to Buy a SAN:
This would be for our VMs. We mostly have application servers and SQL database servers. We have 5 new hosts for VMware to connect up to it.
holy shit - 5 hosts - that's a TON of compute... what are you doing?
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@ScottyBoy said in Looking to Buy a SAN:
The HPE engineer we talked said that's not really the case with them anymore, and they are designed much better these days to handle fault issues.
This is exactly the lie they've told from day one and nothing, literally nothing, has changed - and nothing really can, he's making an impossible claim and banking on you not calling his obvious bluff. This is a lie so brazen that I'd not only never do business with any vendor that said it, I'd charge them with trespassing if they ever tried to speak to us again. This is as false as false gets and they openly just mocked you. Do NOT let them get away with this.
His JOB is to lie to you. He's not an engineer, he's a salesman for the vendor. His job is to trick you, that's his ONLY job. You should never go to a sales person to ask if their product is any good, in doing so you have given him social permission to lie to you because you can't claim that you didn't know that his job was to promote the product and to be totally biased against your interests.
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@ScottyBoy said in Looking to Buy a SAN:
Aside from that we already have bought 5 new hosts (1U hosts with just SD cards for VMware)
Wow. Can you add drives to them? Can you return them? And why VMware, that's crazy expensive and you can't be leveraging their key features because they don't match with the SAN (crazy high end support and availability stuff.)
And while this doesn't matter.... people are buying half the system without having even chosen the other half yet? Where is the holistic decision making to know what products make sense?
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@ScottyBoy said in Looking to Buy a SAN:
The HPE engineer we talked said that's not really the case with them anymore, and they are designed much better these days to handle fault issues.
Aside from that we already have bought 5 new hosts (1U hosts with just SD cards for VMware)
Sadly, this was the cart before horse. If you don't "know" how these hosts are going to connect to their storage, how do you "know" you have the right hosts?
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This sounds like unscrupulous sales people having a field day, honestly. We don't know much about your environment and what you are supporting, but VMware + SAN... this seems crazy. Super high cost on one hand that only has benefits in crazy high end production, and then SAN (and looking at non-production SAN) tied to it so it wouldn't really even classify as a production environment. This is a huge mismatch in apparent goals.
We can only armchair advise so far. But our guess is that someone forgot to look at the goals, went to sales people with a budget rather than requirements, and are getting sold whatever generates the highest margins and no one person has been overseeing the project end to end to verify that it's meeting some business goal for the customer. Just guessing, but that's normally how companies end up in this situation - especially with half the purchase complete and not designed to work with what the other half would need to be.
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@Dashrender said in Looking to Buy a SAN:
@ScottyBoy said in Looking to Buy a SAN:
The HPE engineer we talked said that's not really the case with them anymore, and they are designed much better these days to handle fault issues.
Aside from that we already have bought 5 new hosts (1U hosts with just SD cards for VMware)
Sadly, this was the cart before horse. If you don't "know" how these hosts are going to connect to their storage, how do you "know" you have the right hosts?
Exactly, that's what I was just writing up. Who bought those five servers without knowing what their storage would be? How did they spec them?
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@scottalanmiller said in Looking to Buy a SAN:
You should never go to a sales person to ask if their product is any good, in doing so you have given him social permission to lie to you because you can't claim that you didn't know that his job was to promote the product and to be totally biased against your interests.
This is a point that there are near countless threads here and elsewhere that you should read - and have your management read.
It's interesting how people just don't consider the 'job' of a sales person. They have one job - to sell you the product THEY sell, if they do anything else, then they are cheating their own company, and likely shouldn't work there.
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Here's the catch, let's assume you can't return those 5 servers, you might still be able to get a system that's WAY better than any SAN based solution and save money doing it compared to buying the SAN and using these 5 servers.
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@Dashrender said in Looking to Buy a SAN:
They have one job - to sell you the product THEY sell, if they do anything else, then they are cheating their own company, and likely shouldn't work there.
Right, people often think that "well they'll be honest with me." But they are being honest, they tell you up front where they work and their role. So you know that they are there to sell you something that you wouldn't choose if they didn't talk you into it. They are paid to promote their own product, it would be dishonest to everyone involved if they gave out free, high cost engineering advice that their employer hired them to hide.
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I'm open to options. We have 200vms supporting various roles. Should we look into something like proxmox instead of VMware? I've toyed with it but was told it's not serious for business use and has security issues.
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CDW (which we paid as a consultant, not using their sales department) recommended us to go with a Nimble SAN for the dedup and compression.
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@ScottyBoy said in Looking to Buy a SAN:
I'm open to options. We have 200vms supporting various roles. Should we look into something like proxmox instead of VMware? I've toyed with it but was told it's not serious for business use and has security issues.
LOL, I see it as a bit more serious than VMware. VMware, while not bad, is primarily there to be something to sell via sales people. It's risky and complicated and its good features are only available at extremely high cost and not in your kind of scenario.
Proxmox is very good, and fine for any production environment. But if you are wary of the vendor, and I totally get that as I have my reservations too, then vendors like Fedora and Ubuntu are great if you just want a straight hypervisor, or someone like Scale if you want an appliance that is managed end to end for you.
