Comments on: Replicated Local Storage

By: Shamil

Shamil — Wed, 25 Oct 2017 16:32:49 +0000

Very helpful.. thanks alot for sharing knowledge.

By: gchapman

gchapman — Mon, 01 Jul 2013 18:12:43 +0000

Just found your site today, lots of good stuff there. I’d be curious about your feedback on what we are doing at SimpliVity. I think we offer an attractive platform for the SMB/MID markets that help address a lot of the pain points that the market segment. Not trying to be all “salesy” but its a pretty cool piece of technology.

http://www.simplivity.com/

By: Scott Alan Miller

Scott Alan Miller — Mon, 01 Jul 2013 17:50:05 +0000

As solutions like DRBD are completely synchronous deduplication would not be needed as any deduplication at the source end would be replicated at the receiving end. The synchronous nature makes that not a factor since the two sides need to have their writes done at the same time. The nature of being needed on one end means that it is needed on the other.

Compression can be done, although I’ve never seen anyone try this, but the risk there is that you add latency and latency, more than throughput, is the key concern with synchronous storage replication. So even if there was a good option I think it would be very rare to want to implement it. Providing for GigE or even 10GigE between nodes is trivial in a two node replication model so it is pretty rare that throughput is of concern.

I’m pretty excited that one of the vExperts jumped in here! Thanks for commenting!!

By: gchapman

gchapman — Mon, 01 Jul 2013 17:40:26 +0000

Good points, alas software based replication is not without its faults. If I’m only concerned with file level replication then it can tend to be a simple to deploy tool for a site to site level replication of specific user data, but if I need to replicate an entire workload, ie the virtual machine itself, then the available solutions out there are a bit wanting in terms of functionality.

Second, you can end up replicating data multiple times if the underlying solution doesnt support native deduplication and compression. That is simply a waste of bandwidth and makes the replication process much longer than it should be.