Almost exactly a year ago I published a post covering my first impressions of the ASM Filter Driver (ASMFD) released in Oracle 18.104.22.168, followed swiftly by a second post showing that it didn’t work with 4k native devices.
When I wrote that first post I was about to start my summer holidays, so I’m afraid to admit that I was a little sloppy and made some false assumptions toward the end – assumptions (more...)
For the last couple of years I’ve been writing a series of blog posts introducing the concepts of flash-memory and solid state storage to those who aren’t part of the storage industry. I’ve covered storage fundamentals, some of what I consider to be the enduring myths of storage, a section of unashamed disk-bashing and then a lengthy set of articles about NAND flash itself.
Now it’s time to talk about all flash arrays. (more...)
In a proud moment for me, it appears that Mark Hurd, CEO of Oracle, has mentioned my flashdba blog during the Oracle Q4 2015 results call. At least, that’s what I’m reading into this section from the transcript published by Seeking Alpha:
We grew in storage in the quarter and this is — really we are going through a shift in storage now. We released our SAN product FS1 in the quarter which (more...)
So this is it – the last article in my mini-series on understanding flash. This is the bit where I draw it all together in a neat conclusion that makes you think, “Yes! That was worth reading”. No pressure eh?
So let me start with the conclusion first: as a storage medium, NAND flash is a royal pain in the ass.
Why? Well, let’s look back at what we’ve learned in the previous 9 (more...)
This is a very simple post to show the results of some recent testing that Tom and I ran using Oracle SLOB on Violin to determine the impact of using virtualization. But before we get to that, I am duty bound to write a paragraph of text featuring lots of long sentences peppered with industry buzz words. Forgive me, it’s just the way I’m wired.
It is increasingly common these days to find database environments running (more...)
I’ve run into a few customers recently who have had problems with their ASM rebalance operations running too slowly. Surprisingly, there were some simple concepts being overlooked – and once these were understood, the rebalance times were dramatically improved. For that reason, I’m documenting the solutions here… I hope that somebody, somewhere benefits…
1. Don’t Overbalance
Every time you run an ALTER DISKGROUP <NAME> REBALANCE operation you initiate a large amount of I/O workload as (more...)
I’m delighted to say that this is another guest post from my good friend Nate Fuzi, who performs the same role as me for Violin but is based in the US instead of EMEA. Because he is American, Nate thinks that scones are called “biscuits”, that chips are called “fries” and that there is nothing – *nothing* – that cannot be improved with the simple addition of bacon. Clearly, something is fundamentally wrong with him (more...)
A quick post to say that this week, on Thursday 26th, I will be giving a talk (in English!) on the subject of Flash for DBAs (and architects, designers, developers, managers etc) at the Paris Oracle Meetup:
Flash for DBAs: A new technology is sweeping the world of storage. Flash, a type of non-volatile memory, is gradually replacing hard disk drives. It began in consumer electronic devices such as phones, cameras and tablets (more...)
A few weeks ago, in what seems to be a truly modern phenomenon, I became aware that it was my third anniversary of joining Violin after I noticed a number of people congratulating me on LinkedIn. In many ways it feels like I’ve already been here for a lifetime, but it was only twelve months ago I was trying to think of a suitable flash-based pun for the title of an article just like this one. (more...)
Semiconductor Fabrication Plant (picture courtesy of SemiWiki.com)
Before I draw this series on Understanding Flash to a close, I wanted to briefly touch on the subject of manufacturing. Don’t worry, I’ve taken heed of the kind feedback I had after my floating gate transistor blog post (“Please stop talking about electrons!“) and will instead focus on the commercial aspects, because ultimately they affect the price you will be paying for your flash-based (more...)