The SMB Two Server Dilema, What to Do
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These scenarios work, so reliably, because the lower the total cost of the systems, while lowering the complexity to only what is necessary to accomplish the goals while not adding any additional or unnecessary fragility such as external storage (another point of dependency) or switching (again, more things to depend on) when not needed. Keeping it simple and highly available.
Both of these approaches dramatically improves reliability compared to the reliability of a single server working on its own. Many other approaches do not do this, they work by increasing risk and complexity and then mitigating the increased risk that they introduced rather than mitigating the risks inherent to the original problem.
This two server approach with replicated local storage maintains a single failure domain and mitigates the risks that it contains. It wins the risk game by reducing vertical risk (failure domains or layers) while also reducing horizontal risk (mitigating the risk within the existing failure domain.)
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Scaling up from this approach simply requires a storage layer that will continue to grow horizontally when needed or moving to one that will. Vendors like Starwind, HP VSA, VMware VSAN, Scale, Gluster, CEPH, OpenIO all tackle that scaling problem with this approach.
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@scottalanmiller said in The SMB Two Server Dilema, What to Do:
Scaling up from this approach simply requires a storage layer that will continue to grow horizontally when needed or moving to one that will. Vendors like Starwind, HP VSA, VMware VSAN, Scale, Gluster, CEPH, OpenIO all tackle that scaling problem with this approach.
A bit late but... RDMA and NVMe are game changers really. RDMA bridged NVMe device has better overall performance and a bit (irrelevant) higher latency. This means we'll see a new generation of a Software Defined Storage soon because neither "wide striping" nor "data locality" have any sense anymore
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umm... . not sure if this belong here, but has anyone used Zerto ? Any indication of the price-points ? also, are there any similar product(s)/solution(s) that're free of cost ?
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- XenServer with DRBD. DRBD is fully baked into the platform itself, and completely free and used in many other scenarios such as HA Linux servers and NAS devices. It's a very standard and battle tested component. It runs on XenServer's Dom0 and is included, not an add on. This approach is 100% free top to bottom.
DRBD is NOT included with XS, you have to manually add it via some external repo like elrepo or build it from source.
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@Francesco-Provino said in The SMB Two Server Dilema, What to Do:
- XenServer with DRBD. DRBD is fully baked into the platform itself, and completely free and used in many other scenarios such as HA Linux servers and NAS devices. It's a very standard and battle tested component. It runs on XenServer's Dom0 and is included, not an add on. This approach is 100% free top to bottom.
DRBD is NOT included with XS, you have to manually add it via some external repo like elrepo or build it from source.
Maybe management tools, but DRBD is part of the stock kernel for some time now, including the one in XS' Dom0.
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@Veet said in The SMB Two Server Dilema, What to Do:
umm... . not sure if this belong here, but has anyone used Zerto ? Any indication of the price-points ? also, are there any similar product(s)/solution(s) that're free of cost ?
XenOrchestra does that for free. Although limited value, as DRBD does this better for free as well. You only use this for specific situations where you don't want the full replication.
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@scottalanmiller of course is part of the kernel, but is useless without the management tools.
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@Francesco-Provino said in The SMB Two Server Dilema, What to Do:
@scottalanmiller of course is part of the kernel, but is useless without the management tools.
Yes, but adding a management tool is not the same as adding the functionality. It's not that you are getting something and shoehorning it in, you are just deciding what interface you want to manage the built in functionality with.
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@scottalanmiller said in The SMB Two Server Dilema, What to Do:
@Veet said in The SMB Two Server Dilema, What to Do:
umm... . not sure if this belong here, but has anyone used Zerto ? Any indication of the price-points ? also, are there any similar product(s)/solution(s) that're free of cost ?
XenOrchestra does that for free. Although limited value, as DRBD does this better for free as well. You only use this for specific situations where you don't want the full replication.
From what I read-up on Zerto, is that it can do cross hypervisor replication ... I'm not sure whether DRBD does that ..
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A lot of people don't want third party tools that come from an unknown source. That the DRBD feature is totally built into the kernel and there just waiting to be exposed with an interface is a big deal that makes users feel much better than getting the actual functionality from a different company.
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In scenarios such as these what would be the recommended backup approach: DAS, NAS, Backup Appliance, lower end server, removable disk storage, tapes (intentionally left out cloud)?
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@Veet said in The SMB Two Server Dilema, What to Do:
@scottalanmiller said in The SMB Two Server Dilema, What to Do:
@Veet said in The SMB Two Server Dilema, What to Do:
umm... . not sure if this belong here, but has anyone used Zerto ? Any indication of the price-points ? also, are there any similar product(s)/solution(s) that're free of cost ?
XenOrchestra does that for free. Although limited value, as DRBD does this better for free as well. You only use this for specific situations where you don't want the full replication.
From what I read-up on Zerto, is that it can do cross hypervisor replication ... I'm not sure whether DRBD does that ..
DRBD doesn't care what you use, it just makes identical storage in two locations. It's a pure storage solution, not a "replication" solution. This is network RAID.
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@whizzard said in The SMB Two Server Dilema, What to Do:
In scenarios such as these what would be the recommended backup approach: DAS, NAS, Backup Appliance, lower end server, removable disk storage, tapes (intentionally left out cloud)?
That's a lot more flexible. DAS, removable disk and similar are not very easy to use and backups + hard to use = no backups. NAS, file server, backup appliance and tape are the good solutions and each depends heavily on your needs. Appliances vs. software + storage is basically "what product do you want". NAS vs. file server is just two of the same thing, different look and feel. Tape is the odd man out here, but has a lot of good use cases. It's ability to remain cold, last for a really long time and be totally disconnected from the original storage is all really nice.
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@whizzard said in The SMB Two Server Dilema, What to Do:
In scenarios such as these what would be the recommended backup approach: DAS, NAS, Backup Appliance, lower end server, removable disk storage, tapes (intentionally left out cloud)?
Should be separate (physically!) entity non-related to your production cluster. Cheap NAS is OK.
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@KOOLER said in The SMB Two Server Dilema, What to Do:
@whizzard said in The SMB Two Server Dilema, What to Do:
In scenarios such as these what would be the recommended backup approach: DAS, NAS, Backup Appliance, lower end server, removable disk storage, tapes (intentionally left out cloud)?
Should be separate (physically!) entity non-related to your production cluster. Cheap NAS is OK.
For the average scenario (and I really just mean average) it's Synology or ReadyNAS that I recommend. Easy, supported, cost effective, desktop or rackmount options, well known, good brands, nice features.
