So HA it is
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We have some Colo's at Time Warner Telecom, all Level 3 backbone connections. I'm pretty happy with it.
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@DustinB3403 said:
So in having a discussion with my boss, a few things have been decided. We need the ability to have some level of HA. Likely in the same building. Specifically protecting from scenarios where a single host goes up in flames.
Was this a discussion involving numbers of how much the risk is versus the cost and value of mitigation? Or is it all emotionally driven, which SMBs typically run on emotion and it is what keeps them from becoming enterprises, in many cases. HA should never be a decision from IT, IT isn't the department with the skills or insight to know when HA is appropriate.
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@DustinB3403 said:
So a single Hypervisor Host is off the table.
Most important rule of HA: HA is something that you do, not something that you buy.
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WIth Hyper-V (and probably XenServer) you could use replication to the colocataed server and then local to the colocation backup if also desired.
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I specifically spoke to the reasons why we likely don't need HA. But my boss made the decision, from emotion.
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Key steps to HA involve redundant generators, good fuel supply plan, high availability and very intensive HVAC solutions, that kind of stuff. Your plant is 10 fold as important as your gear.
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@DustinB3403 said:
I haven't looked into any providers, but have considered it. I doubt that we're willing to invest into another server, plus racking cost. I can look into it, do you have any recommendations?
No, sorry we don't have many collocation facilities around here (without driving 3-5 hours). This is something that would be local to you.
I think the long term cost of a server and rackspace would be less then storing 24TB in the cloud (I'm not saying you will do that) you will need to do some cost analysis to see what is the better idea.
You also need to remember the time it takes to retrieve data from the internet. "Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway."
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@coliver Yes, thank you for the reminder.
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@coliver said:
You also need to remember the time it takes to retrieve data from the internet. "Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway."
If it was really important you could get ethernet to the colo and have your internet go out of the colo instead.
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What's your bandwidth? Moving your entire infrastructure to an enterprise collocation site would probably be less expensive then building out a new server room with HVAC, generators, etc. @scottalanmiller beat me to it.
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@coliver said:
What's your bandwidth? Moving your entire infrastructure to an enterprise collocation site would probably be less expensive then building out a new server room with HVAC, generators, etc. @scottalanmiller beat me to it.
Scott may have said something, but your suggestion puts it in black and white. If you're boss isn't willing to put this in a DC, it's probably not worth spending the money on HA.
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I like the potentional not use a backup to get it offsite. I have not done the replication myself, but know another group that has. very little data replicating in each change.
They brought in the server locally, seeded the initial replicas, moved it to the colocation facility, and then let it catch back up.
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@JaredBusch said:
I like the potentional not use a backup to get it offsite. I have not done the replication myself, but know another group that has. very little data replicating in each change.
They brought in the server locally, seeded the initial replicas, moved it to the colocation facility, and then let it catch back up.
I've never done replication over a high latency wire. Not sure how it would work.
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@DustinB3403 said:
The next is the choice of storage, consumer or enterprise grade SSD's. Having a much lower weekly delta change for our shares than the daily delta for the consumer grade SSDs (which the write delta mark for the consumer grade SSD's is 20GB per day), so we have to ask: "Are enterprise drives really worth over double the cost of each SSD?"
Depends if they are part of the server support package or not, and if they will work with your controller or not. Often enterprise SSDs have special firmware to go with your hardware controller. The decision is holistic, not separated out to just consumer vs. enterprise.
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@JaredBusch said:
I like the potentional not use a backup to get it offsite. I have not done the replication myself, but know another group that has. very little data replicating in each change.
They brought in the server locally, seeded the initial replicas, moved it to the colocation facility, and then let it catch back up.
We replicate ours every 5-10min depending on the server. So we see little traffic from this.. Most of the time.
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@Dashrender said:
Scott may have said something, but your suggestion puts it in black and white. If you're boss isn't willing to put this in a DC, it's probably not worth spending the money on HA.
Or another way.... if your boss refuses to do HA, you can't do HA even if he requests HA
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@coliver said:
@JaredBusch said:
I like the potentional not use a backup to get it offsite. I have not done the replication myself, but know another group that has. very little data replicating in each change.
They brought in the server locally, seeded the initial replicas, moved it to the colocation facility, and then let it catch back up.
I've never done replication over a high latency wire. Not sure how it would work.
Latency does not affect replication. That is the benefit of it.
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@JaredBusch said:
@coliver said:
@JaredBusch said:
I like the potentional not use a backup to get it offsite. I have not done the replication myself, but know another group that has. very little data replicating in each change.
They brought in the server locally, seeded the initial replicas, moved it to the colocation facility, and then let it catch back up.
I've never done replication over a high latency wire. Not sure how it would work.
Latency does not affect replication. That is the benefit of it.
Good to know.
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@coliver said:
I've never done replication over a high latency wire. Not sure how it would work.
If it is async, hardly affects it at all. As long as you are replicating in the "minutes" range and not in the "seconds" range. High latency wire is normally no more than 300ms and 2,000ms tops.
Full Sync is super latency sensitive because every write has to be confirmed before anything continues.
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@coliver said:
Good to know.
It is basically just like transaction logging in SQL server. It writes the changes to a log file and then ships the log file. There is not a concern for latency. Obviously, you need to still have enough bandwidth for these changes. or you will always be getting farther behind, but because it is replicating, there is never a problem like a new full backup.
