Triple mirroring requires complete copies of data to be stored in three locations, while 3-geo OBS configuration distributes erasure encoded fragments of data across three locations. 3-geo OBS uses approximately 48% less storage than triple mirroring and consumes less bandwidth. It also allows data to be rehydrated from a subset of locations and has no rebuild or failover times. Management of the 3-geo OBS configuration is also centralized through a single console.

1. Quick FAQ
Triple Mirroring vs.
3-Geo OBS Configuration

2. Triple Mirroring vs. 3-Geo OBS Configuration
Remote
DR Site
Remote
DR Site
OR
Westchester NYC Jersey City
WAN
Jersey City, NJ
New York City, NY
Westchester Co., NY
3 Redundant Sites
One System Spread
Across 3 Sites
BitSpread™
Resilience is a system attribute
Self-healing and no SPOF
48% reduction of the Disk Overhead of Triple Mirror*
*based upon Western Digital Corporation internal testing

3. Triple Mirroring vs. 3-Geo OBS Configuration
Triple Mirroring requires 3 identical data stores in 3 discrete locations, each with its own
complete copy of the data. Whereas a 3-geo OBS configuration distributes one data
store across 3 locations, each containing 1/3 of the erasure encoded data.
Why you should care
• You can protect data while using ~48% less storage* (160% vs. 300% of data) and
consume less network bandwidth with 3-geo OBS compared with triple mirroring.
• You can manage a 3-geo OBS as a single namespace through one management console.
• You can rehydrate data from only a subset of the erasure coded objects even if an
entire data center is not accessible and there are no “failover” or “rebuild” times.
*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

4. Thanks for watching
Clay Ryder
DCS Marketing
itblog.sandisk.com/author/clayryder

5. © 2017 Western Digital Corporation. All rights reserved. Western Digital, the Western Digital Logo, and BitSpread 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/
@WesternDigiDC
SanDisk Data Center Solutions
@BigDataFlash
HGST, a Western Digital brand