Disclaimer: I recently attended Storage Field Day 7. My flights, accommodation and other expenses were paid for by Tech Field Day. There is no requirement for me to blog about any of the content presented and I am not compensated in any way for my time at the event. Some materials presented were discussed under NDA and don’t form part of my blog posts, but could influence future discussions.
For each of the presentations I attended at SFD7, there are a few things I want to include in the post. Firstly, you can see video footage of the Kaminario presentation here. You can also download my raw notes from the presentation here. Finally, here’s a link to the Kaminario website that covers some of what they presented.
Dani Golan, CEO of Kaminario, gave us a quick overview of the company. They’ve recently launched the 5th generation of their all-flash array (AFA), with the majority (80%) of customers being in the midrange (rev $100m – $5B).
The entry level for the solution is 20TB, with the average capacity being between 50 and 150TB. The largest implementation runs to 1.5PB.
Use cases are primarily:
- VDI / Virtualisation;
- Analytics; and
Kaminario state that they’re balanced across all verticals and offer general purpose storage.
Kaminario state that architecture is key. I think we’re all agreed on that point. Kaminario’s design goals are to:
- scale easily and cost-efficiently; and
- provide the lowest overhead on the storage system to fulfil the customer’s needs.
Kaminario want to offer capacity, performance and flexibility. They do this by offering scale up and scale out.
Customers want somewhere in between best $/capacity and best $/performance.
The K2 basic building block (K-blocks, not 2K blocks) is:
- Off the shelf hardware;
- 2x K-nodes (1U server);
- SSD Shelf (24 SSDs – 2RU); and
- SSD expansion shelf (24 SSDs – 2RU).
Here’s a diagram of the K2 scale up model.
And here’s what it looks like when you scale out.
I want to do both! Sure, here’s what scale up and out looks like.
In the K2 scale-out architecture:
- Data is spread across all nodes;
- Metadata is spread across all nodes;
- Provides the ability to mix and match different generations of servers and SSDs;
- Offers global deduplication; and
- Provides resiliency for multiple simultaneous failures.
Data is protected against block (nodes and storage) failure, but the system will go down to secure the data.
As for metadata scalability, modern data reduction means fine grain metadata:
- Pointer per 4KB of addressable; and
- Signature per 4KB of unique data.
According to Kaminario, reducing the metadata footprint is crucial.
- The adaptive block size architecture means less pointers;
- Deduplication with weak hash reduces signature footprint; and
- Density per node is critical.
K-RAID is Kaminario’s interpretation of RAID 6, and works thusly:
- 2P + Q – 2 R5 groups, single Q parity on them;
- Fully rotating, RAID is fully balanced;
- Fully automatic, no manual configuration; and
- High utilisation (87.5%), no dedicated spares.
The K2 architecture also offers the following data reduction technologies:
- Global and adaptive;
- Selective – can be turned off per volume; and
- Weak hash and compare – low MD and CPU footprint, fits well with flash.
- Byte-aligned compression;
- Adaptive block size – large chunks are stored contiguously, each 4k compressed separately;
- Standard LZ4 algorithm; and
- Optimized zero elimination.
From a resiliency perspective, K2 supports:
- Two concurrent SSD failures per shelf;
- Consistent, predictable and high performance under failure; and
- Fast SSD firmware upgrades.
The architecture currently scales to 8 K-Blocks, with the sweet spot being around 2 – 4 K-Blocks. I strongly recommend you check out the Kaminario architecture white paper – it’s actually very informative.
Final Thoughts and Further Reading
I first came across Kaminario at VMworld last year, and I liked what they had to say. Their presentation at SFD7 backs that up for me, along with the reading I’ve done and the conversations I’ve had with people from the company. I like the approach, but I think they have a bit of an uphill battle to crack what seems to be a fairly congested AFA market. With a little bit more marketing, they might yet get there. Yes, I said more marketing. While we all like to criticise the marketing of products by IT vendors, I think it’s still a fairly critical piece of the overall solution puzzle, particularly when it comes to getting in front of customers who want to spend money. But that’s just my view. In any case, Enrico did a great write-up on Kaminario – you can read it here. I also recommend checking out Keith’s preview blog of Kaminario.