NAND flash is a genuinely difficult storage medium – it wears out, has slow erases, and requires complex management. This article summarises the Understanding Flash series and explains why architecture is what separates great all-flash arrays from merely fast ones.
SLOB benchmark results measuring the I/O overhead of virtualisation on Violin flash – comparing VMware ESX against Oracle VM to see which hypervisor costs less in raw database performance.
Slow ASM rebalance operations usually come down to a handful of overlooked settings. Here are three practical fixes that have dramatically cut rebalance times in real customer environments.
Running Linux DM-MPIO alongside EMC PowerPath requires careful configuration to avoid conflicts. Here's a precise walkthrough of how to make them coexist correctly.
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 … Continue reading Paris Oracle Meetup (Jeudi 26 Mars 2015 @ 7pm)
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 … Continue reading Postcards from Storageland: Three Years At Violin
NAND flash manufacturers have been shrinking transistors for decades, but 2D planar NAND is hitting its physical limits. This article explains process geometries, 3D NAND as the answer, and why new memory technologies face a billion-dollar barrier to market.
Now that the dust has settled on the announcement of Oracle's new Exadata X5 Database Machine, I've been doing some research in order to update my History of Exadata post (it'll be ready soon). While reviewing the datasheets and other collateral for the X5 I was struck by the meteoric increase in one particular statistic: the … Continue reading Oracle Exadata X5: The Road To Ten Billion Dollars
Oracle deprecated the non-CDB architecture in 12c, signalling a forced migration to Multitenant. Here's what that means for DBAs still running traditional single-instance databases.
NAND flash wears out because repeated program and erase operations degrade the oxide layer in floating gate transistors. This article explains how flash cells store data and why wear affects SLC, MLC and TLC differently.
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