HA/DR solutions

  • The company I work for is pretty small and currently we have 20+ DBs running on 2008r2 and 2012. DB sizes are anywhere between 50 to 250 GB. As of now, we rely on our backups and have no HA/DR solution in place. Now we are thinking about it but don't know which solution to go with because of the limited budget the company has. Any recommendation?

  • Personally, I've had good experience using a separate DR device that's basically a separate machine that's entire focus is backing up locally and offloading to a external cloud platform for offsite/HA in case of fire. It wasn't too expensive for a small business ($10K) with a monthly subscription and it's own directive of ShadowProtect that allowed daily/weekly snapshots of the servers and the database along with my own daily/weekly database backups. This was able to be automated and provided offsite DR with a cloud service you could spin up the entire infrastructure in case you get destroyed by Skynet or aliens.

    We eventually replaced it years later, but it served a small business well.

  • If you have the hardware (or VM's) for a failover setup, then DH2i's DxEnterprise is a nice HA/DR solution.  We don't use it for a full DR solution, but if one of our SQL Server servers dies on us, it will fail it over to a second one pretty darn fast.

    Where I work, we have about 20 live databases and a bunch of test and we use DxEnterprise for our HA on live.  One server hosting SQL goes down, it fails over (disks and all) to the second and starts stuff back up.  Very similar to Polyserve (for those who remember that tool), but more modern and works better from my experience.  They add new features all the time.  They are even getting it working with both Linux and Docker.

    product demo video - https://youtu.be/XXau278uOVc

    As for the cost, I do not remember what it was unfortunately, but in my opinion you do not want to cheap out on a HA/DR solution.  I would do a cost analysis of how much money your company will lose per hour of downtime and compare that to the cost of an HA/DR solution.  One SQL instance going down might not cost that much for the company, but you generally buy these types of tools for if the whole server goes down at once, not an individual instance.  Where I work, losing a server meant we would be losing a LOT of money per hour and the software then came out to be relatively cheap.

    It depends too on the need.  xsevensinzx's solution would be good if you require uptime when your building is down.  DH2i's solution is nice if you want to run everything on premise (ie not in the cloud).  Where I work, there is still the fear that the cloud is insecure, so we want as much as we can on premise.  We have multiple buildings though so if the main one goes down, things are recoverable.

    NOTE - I do not work for DH2i; I just really like their tool.

    The above is all just my opinion on what you should do. 
    As with all advice you find on a random internet forum - you shouldn't blindly follow it.  Always test on a test server to see if there is negative side effects before making changes to live!
    I recommend you NEVER run "random code" you found online on any system you care about UNLESS you understand and can verify the code OR you don't care if the code trashes your system.

  • HA and DR are 2 different, but related things...like cousins, not twin siblings 🙂

    How much disaster are you wanting to recover from?   Database deleted?  Server toasted? Server room?  Building? City?   As you get wider the choices are more plentiful but also more expensive.

    If you don't need crazy fast HA, Might I suggest Log Shipping to a different data center?  That will protect your user databases, and allow for a manual "failover" in the event the primary goes down.  It can be a lesser box if necessary due to budget.  Also, you can put a delay on how current it is, which allows you to save yourself from the dreaded "Oops" moment when someone deletes the DB, or drops a critical table.

    ------------------------------------------------------------------------------------------------Standing in the gap between Consultant and ContractorKevin3NFDallasDBAs.com/BlogWhy is my SQL Log File HUGE?!?![/url]The future of the DBA role...[/url]SQL Security Model in Plain English[/url]

  • bmg002 - Wednesday, May 10, 2017 12:32 PM

    It depends too on the need.  xsevensinzx's solution would be good if you require uptime when your building is down.  DH2i's solution is nice if you want to run everything on premise (ie not in the cloud).  Where I work, there is still the fear that the cloud is insecure, so we want as much as we can on premise.  We have multiple buildings though so if the main one goes down, things are recoverable.

    Just a bit of clarification here too. You can run your VM's on that device too if the hardware fails. Cloud is for the building/major issues. 🙂

  • This was removed by the editor as SPAM

  • I am not sure how true that is but I heard that the secondary server in log shipping doesn't have to be licensed. Is that true?

  • On the availability side, we use Windows Server Failover Cluster.  Perry Whittle has a stairway series on this site at http://www.sqlservercentral.com/stairway/112556/.  His part 4 at http://www.sqlservercentral.com/articles/cluster/107539/ covers WSFC.  I learned a lot about how it works from these articles.  It's so much nicer on Windows Server 2012 than on previous versions of Windows that I'd recommend you start there.

    Disaster recovery is a different animal and requires a different midset.  Like Kevin pointed out above, you need to consider different types of disasters.  I generally go to the physical destruction of a building and everything in it.  You data has to exist elsewhere so it can be recovered.  Our data, logs and backups all live on SAN volumes.  We copy our backups from live SAN to a completely different SAN in a different location.  It's done by the SAN management software and managed by the domain administrators.  Because it's handled by the SAN software, it's ridiculously fast.  I'm sure there are far better solutions out there, but like you, I'm pretty heavily constrained by budgetary limitations.

  • newdba2017 - Wednesday, May 17, 2017 4:28 PM

    I am not sure how true that is but I heard that the secondary server in log shipping doesn't have to be licensed. Is that true?

    I think (but am not sure...call microsoft) that if you only use it for DR you are ok.  If you set log shipping in standby/read-only, you need to license it.   

    Always call MS licensing number...never trust the internet people 😉

    ------------------------------------------------------------------------------------------------Standing in the gap between Consultant and ContractorKevin3NFDallasDBAs.com/BlogWhy is my SQL Log File HUGE?!?![/url]The future of the DBA role...[/url]SQL Security Model in Plain English[/url]

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