Feeds

Microsoft flash research inspires EMC

Data Domain flash-based dedupe coming

Intelligent flash storage arrays

EMC is using Microsoft research into flash use as a memory tier between DRAM and disk drives to speed up Data Domain deduplication.

FlashStore is a Microsoft research project that batches up flash writes in a server's main memory and then writes them as a page or block, in effect turning random flash writes into sequential ones and avoiding block erase/write cycles that are otherwise endemic to flash.

Such cycles both slow down flash writes and can shorten its working life by increasing the number of block erase/write cycles in a time period, flash blocks having a finite erase/write cycle capacity.

The Microsoft researchers Sudipta Sengupta, Jin Li and intern Biplob Debnath said FlashStore minimises its DRAM footprint by using an index to access the data in the flash cache.

This is a key:value store using a hash-table index. Microsoft tells us it saves space on both the vertical and horizontal dimensions of the table by using a version of cuckoo hashing - where keys in table slots serve as eggs pushed out of the nest - to reduce the number of slots and slot sizes in the hash table.

In cuckoo hashing, as we understand it, for any key value two hash functions are used instead of one, giving the key two possible locations in the table instead of one. Any pre-resident key in that slot is booted out and it is then put in its alternative slot, booting out any already resident key until an empty slot is found.

Apparently this saves up on lookup time, with just two slot inspections needed. But the table has to be less than half full and, if it gets full, it has to be rebuilt because there isn't an empty slot for the last displaced key value hash.

Returning from computer science territory

The researchers say that the FlashStore DRAM table is frugal in its use of DRAM and provides fast access time with an average of a single flash read per lookup. This means servers using it can perform many times faster; "several tens of factors of increased data throughput" is the phrasing they use.

Sengupta says this about applications with high IOPS needs: "You could replace 10 to 20 hard drives with one flash drive using FlashStore for such applications.

"That gives you a capital-expenditure savings, power savings, and operational-expenditure savings, as well, and you also get much faster throughput: an all-win situation on the three metrics of price, power, and performance.”

Deduplication

It sounds like deduplication could use this technique. Microsoft's FlashStore paper says: "FlashStore also achieved significantly better results than a RAM/hard drive or a flash drive when tested with the task of performing data-chunk indexing for data deduplication."

Beginner's guide to SSL certificates

More from The Register

next story
The cloud that goes puff: Seagate Central home NAS woes
4TB of home storage is great, until you wake up to a dead device
Azure TITSUP caused by INFINITE LOOP
Fat fingered geo-block kept Aussies in the dark
You think the CLOUD's insecure? It's BETTER than UK.GOV's DATA CENTRES
We don't even know where some of them ARE – Maude
Intel offers ingenious piece of 10TB 3D NAND chippery
The race for next generation flash capacity now on
Want to STUFF Facebook with blatant ADVERTISING? Fine! But you must PAY
Pony up or push off, Zuck tells social marketeers
Oi, Europe! Tell US feds to GTFO of our servers, say Microsoft and pals
By writing a really angry letter about how it's harming our cloud business, ta
SAVE ME, NASA system builder, from my DEAD WORKSTATION
Anal-retentive hardware nerd in paws-on workstation crisis
prev story

Whitepapers

Choosing cloud Backup services
Demystify how you can address your data protection needs in your small- to medium-sized business and select the best online backup service to meet your needs.
Forging a new future with identity relationship management
Learn about ForgeRock's next generation IRM platform and how it is designed to empower CEOS's and enterprises to engage with consumers.
Reg Reader Research: SaaS based Email and Office Productivity Tools
Read this Reg reader report which provides advice and guidance for SMBs towards the use of SaaS based email and Office productivity tools.
The hidden costs of self-signed SSL certificates
Exploring the true TCO for self-signed SSL certificates, including a side-by-side comparison of a self-signed architecture versus working with a third-party SSL vendor.
Top 5 reasons to deploy VMware with Tegile
Data demand and the rise of virtualization is challenging IT teams to deliver storage performance, scalability and capacity that can keep up, while maximizing efficiency.