Know Thy Storage
Quick FAQHow Does Erasure Coding Protect Data?
How Does Erasure Coding Protect Data?
RAID protects disk drives
Erasure Code protects data
Erasure Code
Data
Raid6.svg by CBurnett, DrJolo Licensed under Creative Commons By
Attribution-ShareAlike 3.0
(http://creativecommons.org/licenses/by-sa/3.0/), via Wikimedia
Commons
Protecting Your Data with Erasure CodingErasure code is
appliedErasure Code
Data
First object is receivedData is committed to diskSecond object
is receivedErasure code applied to new dataData is committed to
(potentially different) disksProtection against multiple concurrent
failuresHighly resilientNo concept of rebuild timeData rehydrates
on the fly
Only a subset of the shards is required
3
How Does Erasure Coding Protect Data?Erasure Coding protects
data by breaking it into shards that are parity encoded and then
stored across multiple storage media and locations.
Why you should careYou can focus on protecting data, not
hardware.You only need a subset of the shards to rehydrate data.You
can always access your data. Even with hardware failure, there is
no data rebuild time. You can protect data at a fraction of the
expense and overhead of mirroring/replication*. *per Western
Digital Corporation internal testing: using 3-geo erasure coding
requires 1.57x to 1.88x storage capacity compared with 3x required
for triple mirroring
Thanks for watchingClay RyderDCS Marketing
itblog.sandisk.com/author/clayryder
2017 Western Digital Corporation. All rights reserved. Western
Digital and the Western Digital Logo are registered trademarks of
Western Digital Corporation or its affiliates in the U.S. and/or
other countries. All other marks are the property of their
respective owners.
"Faster Does It" Kevin MacLeod (incompetech.com) Licensed under
Creative Commons: By Attribution 3.0
http://creativecommons.org/licenses/by/3.0/
@WesternDigiDCSanDisk Data Center Solutions
@BigDataFlash
HGST, a Western Digital brand
6
