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Under the Covers of a Distributed Virtual Computing Platform – Built For Scale and Agility – via @dlink7, #Nutanix
I must say that Dwayne did a great job with this blog post series!! It goes into expelling the Nutanix Distributed File System (NDFS) that I must say is the most amazing enterprise product out there if you need a truly scalable and agile Compute and Storage platform! I advise you to read this series!!
Under the Covers of a Distributed Virtual Computing Platform – Part 1: Built For Scale and Agility
Lots of talk in the industry about how had software defined storage first and who was using what components. I don’t want to go down that rat hole since it’s all marketing and it won’t help you at the end of the day to enable your business. I want to really get into the nitty gritty of the Nutanix Distributed Files System(NDFS). NDFS has been in production for over a year and half with good success, take read of the article on the Wall Street Journal.
Below are core services and components that make NDFS tick. There are actually over 13 services, for example our replication is distributed across all the nodes to provide speed and low impact on the system. The replication service is called Cerebro which we will get to in this series.
This isn’t some home grown science experiment, the engineers that wrote the code come from Google, Facebook, Yahoo where this components where invented. It’s important to realize that all components are replaceable or future proofed if you will. The services\libraries provide the API’s so as newest innovations happen in the community, Nutanix is positioned to take advantage.
All the services mentioned above run on multiple nodes in cluster a master-less fashion to provide availability. The nodes talk over 10 GbE and are able to scale in a linear fashion. There is no performance degradation as you add nodes. Other vendors have to use InfiniBand because they don’t share the metadata cross all of the nodes. Those vendors end up putting a full copy of the metadata on each node, this eventually will cause them to hit a performance cliff and the scaling stops. Each Nutanix node acts a storage controller allowing you to do things like have a datastore of 10,000 VM’s without any performance impact… continue reading part 1 here.
Under the Covers of a Distributed Virtual Computing Platform – Part 2: ZZ Top
In case you missed Part 1 – Part 1: Built For Scale and Agility
No it’s not Billy Gibbons, Dusty Hill, or drummer Frank Beard. It’s Zeus and Zookeeper providing the strong blues that allow the Nutanix Distributed File System to maintain it’s configuration across the entire cluster. Read more…
Single File Restore – Fairy Tale Ending Going Down History Lane – via @Nutanix and @dlink7
Great blog post by Dwayne Lessner!
If I go back to my earliest sysadmin days where I had to restore a file from a network share, I was happy just to get the file back. Where I worked we only had tape and it was crapshoot at the best of times. Luckily, 2007 brought me a SAN to play with.
The SAN made it easier for sure to go back into time and find that file and pull it back from the clutches of death by using hardware based snapshots. It was no big deal to mount the snapshot to the guest but fighting with the MS iSCSI initiator got pretty painful, partly because I had a complex password for the CHAP authentication, and partly because clean-up and logging out of the iSCSI was problematic. I always had ton of errors, both in the windows guest and in the SAN console which caused more grief than good it seemed.
Shortly after the SAN showed up, VMware entered my world. It was great that I didn’t have to mess with MS iSCSI initiators any more but it really just moved my problem to the ESXi host. Now that VMware had the LUN with all my VMs, I had to worry about resignatureing the LUN so it wouldn’t have conflicts with the rest of production VMs. This whole process was short lived because we couldn’t afford all the space the snapshots were taking up. Since we had to use LUNS we had to take snapshots of all the VMs even though there were a handful that really need the extra protection. Before virtualization we were already reserving over 50% of the total LUN space because snapshots were backed by large block sizes and ate through space. Due to the fact that we had to snapshot all of the VMs on the LUN we had to change the snap reserve to 100%. We quickly ran out of space and turned off snapshots for our virtual environment.
When a snapshot is taken on Nutanix, we don’t copy data, nor do we copy the meta-data. The meta-data and data diverge on a need basis; as new writes happen against the active parent snapshot we just track the changes. Changes operate at the byte level which is a far cry from the 16 MB I had to live with in the past.
Due to the above-mentioned life lessons in LUN-based snapshots, I am very happy to show Nutanix customers the benefits of per-VM snapshots and how easy it to restore a file.
To restore a file from a VM living on Nutanix you just need to make sure you have a protection domain set up with a proper RPO schedule. For this example, I created a Protection Domain called RPO-High. This is great as you could have 2,000 VMs all on one volume with Nutanix. You just slide over what VMs you want to protect; in this example, I am protecting my FileServer. Note you can have more than one protection domain if you want to assign different RPO to different VMs. Create a new protection domain and add 1 VM or more based on the application grouping.
The IT Melting Pot! 