ENERGY STAR® Data Center Storage
DRAFT Initial Data Collection Procedure
November 2009

Introduction
As part of the ENERGY STAR Data Center Storage specification development process,the EPA is inviting interested parties to perform a series of tests and performancemodeling exercises on data center storage systems using the protocol specified in thisdocument.
The objective of this first round of data center storage power consumption testing is tounderstand the relationship between hardware and software configuration and systemenergy performance in both Active and Idle states. EPA would like to collect a
substantial amount of test data and simulated (modeled) test results in order to performa sensitivity analysis on the effect of single-variable configuration changes on power
consumption. Items such as Hard Disk Drive (HDD) selection (e.g. capacity vs.
performance), Reliability, Availability, Serviceability (RAS) features (e.g. single vs.
redundant controllers, RAID level), and use of Small Form Factor (SFF) and Solid State
Disk (SSD) technologies are all of interest.
Data submissions will be collated, anonymized, and made available to the stakeholder
community for analysis in preparation for the first draft Version 1.0 ENERGY STAR
Data Center Storage specification.

Definitions & Acronyms
Maximum Time to Data (MaxTTD): The maximum time before an entire data object isaccessible within the constraints imposed by its storage media. For random-accessmedia, a data object is accessible when any byte may be accessed. For sequentialaccess media, a data object is accessible when the requested object has begun
streaming from a previously inactive drive.
Maximum Sustainable Performance: Maximum IOPS or GB/s that the UUT is able todeliver under a specified workload. To be considered sustainable, the performance
metric must be maintained within 5% for the duration of the test phase.
Response Time: The time required for the UUT to complete an I/O request.
Generic System Configurations (GSC): Four GSC options are proposed as a baseline
for discussion:
GSC-1:
GSC-2:
GSC-3:

Transaction-oriented Value Configuration
Transaction-oriented High-reliability Configuration
Archival/Streaming-oriented Value Configuration

ENERGY STAR Data Center Storage
DRAFT Initial Data Collection Procedure

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GSC-4:

Archival/Streaming-oriented High-reliability Configuration

Note that the specifics of each configuration will be up to the individual vendor or test
facility and dependent on product options, availability of components, test equipment,and other resources. The data collection process will be sufficiently detailed to capture
hardware and software configuration details that are pertinent to energy consumption.
Within many of the taxonomy cells, it will be possible to configure a system that isrepresentative of a typical high-volume customer installation for each of the GSC
classifications. For example, in the Online-3 taxonomy category, a GSC-1 system
would likely utilize high-speed, high-performance HDDs or SSDs with minimal RAS
hardware and software features installed; whereas a GSC-2 system may include
additional RAS features such as redundant controllers, mirroring, and other RAS
features. There are other taxonomy categories for which certain GSC classifications
would not be representative of actual customer implementations (e.g. the Removable
Media Library taxonomy category does not lend itself to transaction-oriented GSC-1 andGSC-2 applications), and there is no expectation that these non-realistic configurations
be tested.

Scope
This document references the v0.0.18 DRAFT “SNIA Green Storage Power
Measurement Specification” Storage Taxonomy Summary, shown here as Figure 1.
Additional details may be found at: http://www.snia.org/green/.
Figure 1: SNIA GSI Storage Taxonomy
OnllineOnStorage
Sto

Near On
NearOnline
StoSt
orage

Prime ststororagage,e, abl
able
e to serve
random as well as sequentequentiial
workloads with mininim
mal deldelayay

IntendInten
ded as second titierstorage behi
behinnd Online
Stororage.
age. Able to service
RandomRandom and Sequequent
entiialworkloads, but pe
perrhaps withnotiiceabl
noteablee delay
delay in titim
me to 1stdata
data acc
access.

Storagagee Taxonom
Taxonomyy SuSummmaryMaximu
mumm Ca
Capacitityy Guidan
Guidance
Note: Maxi mum C ap ac ity Gui danc
dancee r efl ects the maxi mum c ap ac ity a gi
givven ofofferin g can be p urch ased wi
with and/o
and/or fieleldd upgra
upgr aded t o. It is intend
ended
ed

to be used as
as a gu
guiideldeliine as app
appo
osed to an abs
absol
olututee value. There wi
willl be cca
ase wher
where a device mamayhave grea
hav
eatter or smal
alll capa
capabibillities, bu
butt othe
herrwise is an appro
approppri
ria
ate match fo
for a gigiven
ven clcla
assi
siffi catcatiion due
to otheherr cri
critteria, e.g.: redun
edundancdancy
y capabicapabilli ties

Max StStorage
Devi
De
vic
ces

Max StoStorage
Devi
Devic
ces

(Up to 80 Ms MTTD)(Over 8080Ms MTTDMTTD)

Up to 4 Devices

MTTD = Max Time to Data
Maximum time needed toaccess any data stored in any
place on the storage system

Removabl
RembleeMedMe
dia
Libra
Libra ri e sVirtVi
rtuualMed
Me
dia
Librar
Librariies

Archival storora
age usused
ed inin asequeequenti
ntia
al ac
acc
cess mode. A
Typi
piccal exexam
ampl
plee would
would bebeTape babased ararc
chivalal,, bot
bothhStand Al
Alonong
g andand Robot
Robotiicalalllyassassisted lilibr
brarariies.

Stor
orage
age which si
sim ulates
removabl
blee MediMediaa Lib
Libraries.
W ill typipiccally ususe
e non
non tapetapebased ststor
ora
age andand as suchare abable to respond to data
requques
ests
ts more qui
quic
ckly

Infrastr
Infra
tru
uctur
turee
Appl
pplianiances
ces

Infr
fra
astr
tru
uctur
turee
Inte
Int
erconnonnec
ectt

Devices pl
Devi
plac
aced
ed in
in the storora
age
SAN or net
networwork
k addiddin
ng valuethrougthr
oughh one oror more dededi
diccatedStor
orage
age enhaenhancncem
ement
entss.
Exam
amp
ples include: SASANN
Virrtua
Viuallizatition,on, ComComp
pression, De
De-dupldupliicati
ation,on, etetcc.

Devices whi
Deviwhicch ena
enabl
blee a SASAN
Nor othothe
er Stororag
agee Networ
Networkdata
data switching or rout
outiing.

Max StStorageDeviDe
vicecess Suppor
Supporte
ted*d*

Max Tape
Tape DrDriives

Max PorPortt CountGroup 1) SoH
SoHoo & Co
ConsumernsumerStorora
age which is design
gned
ed primari
arilly for home (cononsusummer) orhomhome / smal
alll office usagagee.

Stand AlStandAlononeeDriive
Dr

Note: * Infrastructure
Appliances by definition haveno intrinsic storage, otherthan what is used for local
processing and/or local
Cashing of data.

(No RobotRobotiics)–Of ten Di
Dirrect Conne
Conneccted (USB, IP, etc)
–No opopttion fofor redundanedundancycy (will contntai
ainn SPO
SPOFsFs))

Storage Devices Support in thiscase refers to the number ofstorage devices controllable
down stream of the ApplianceGroup 2) En
Entrtryy, DAS, or JBJBODOD
Storage which isStois dededidic
cated to one or at most a ververyy limited
numbmbeer of servers. Often will nonot inincclude any inteteg
gratedcontcontrorolller, but rerelly on se
serrver hohostst for that function
onaality.

More than 4
Devices

Up to 4 Devices

Up to 4 Drives

More than 20
DevicesMore than 4
DevicesMore than 4Drives

Up to 100
Devices

Supp
Su
pport
ort for up to20 De
Devices

Up to 12128
8

More than 100
DevicesMore than 100
DevicesMore than 24
DrivesMore than 100
Devices

SupporSupp
ortt for morethan 20 Device
cessMore than 128

More than 11
DrivesMore than 100
Devices

SuppSupporortt for morethan 100
100 DeDevices

Up to 32

–Of ten Di
Dirrect ConneConnec
cted (SATA, IP, etetcc .)–May opopttional
onallly ofofffer limi ted num
numbe
berr of redu
edundanndancycy feateatuuresGroup 3) Entr
tryy / Mi
Midr
drang
angee
SAN or NAS connected stor
orag
age
e wh
which plplac
ace
es a higher
emp
em
phasis on value ththan scalability anandd pe
perf
rfor
ormmance. ThiThiss isoften rerefferr
rreed to as ‘Ent
ntrry Le
Lev
vel’ ststor
oragage.
e.
–Net–Netw
work connected (IP,(IP, SAN, etetc.
c.))–Has option
onss for redundanedundanc
cy feataturures
esGroup 4) MidrMidraange / Ente
Enterprise
SAN or NAS coSAN
connnnec
ectted sto
storage which delivers a bal
balancnce
e ofperrformancpence
e andand fefeatures. Offers hihiggher level ofmanmanagememen
nt as we
wellll as scalability and relia
liabbilility
tycapabi
abillities
es..
–Netw–Net
work connected (IP,(IP, SAN, etetc.
c.))–Has optionons
s for and ofoftten deldeliivered wi th full redunda
edundanc
ncyy (no SPOF)

Group 5) EnEnter
terp
prise / Mainfr
infra
ame
StorageStor
age which exhi
exhibits large scal
scala
ability and extreme
robu
robuststne
ness
ss assoc
associiated wi
witth Mainfram
ame
e deployment
nts,s, thououg
gh
are not reres
stri
rict
cted
ed to Mainfram
ame
e onl
only dedepl
ploy
oym
ment
nts.
s.

More than 1000
Devices–Mai
ainnframe conne
onnec
ctivi ty wiwitth op
opttional network connec
onnecttion (IP, SAN..)–Always delideliverereded wi
wi th full redu
redundanndancycy (no SPOSPOFF)–Of ten Capabl
Capablee of nonon-didisrup
sruptti ve serviceab
eabiili ty© SNIA 2009

ENERGY STAR Data Center Storage
DRAFT Initial Data Collection Procedure

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For purposes of Round 1 data collection, EPA is interested in the following taxonomy
classifications:••••

ONLINE: Groups 2, 3, 4, and 5
NEAR-ONLINE: Groups 2, 3, 4
REMOVABLE MEDIA LIBRARY: Groups 2, 3, 4 and 5VIRTUAL MEDIA LIBRARY: Groups 3, 4, and 5

Objective
Stakeholders are encouraged to submit power consumption data for as many products,
in as many Generic System Configurations (GSCs), as can be reasonably
accomplished during the data collection period. If possible, testing and modeling should
be repeated on similar systems after making single-variable changes to the hardware orsoftware configuration. Examples of single-variable changes include:••••

Change disk drive type or technology
Add or remove storage capacity
Modify RAID configuration
Change from single to redundant controllers

Any simulation models used to generate data must be capable of predicting variations inenergy consumption for the various phases of the test sequence. All models should be
run using the test workload sequences defined below for the appropriate taxonomy
category.
In order to assess model accuracy, stakeholders should model any system
configurations that are tested so that results can be easily compared. Further modelingexercises can then be used to simulate the impact of a wide variety of additional singleand multi-variable hardware and software configuration changes.
To summarize, EPA is interested in collecting the following, in order of priority:
1. Data from testing of as many GSCs as possible.
2. Data from re-testing of GSCs after single-variable changes to hardware orsoftware configuration.
3. Data from modeling of any tested system configurations
4. Data from modeling of additional single- or multi-variable changes to hardware orsoftware configuration.

Test Setup
TEST EQUIPMENT
UUT input voltage and power should be measured with a power meter at an appropriate
location to capture the total power consumed by all components of the UUT. This may
be at the PDU, or some other appropriate location. The power measurement should
include all items needed to provide for the integration and operation of the UUT. ThisENERGY STAR Data Center Storage
DRAFT Initial Data Collection Procedure

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includes controllers, drawers, robotic assemblies, power distribution / PDUs as well as
data networking used internal to the UUT (e.g. integrated SAN switches).
The power meter shall have the following capabilities:• Measure and record UUT input voltage with an accuracy of 1% and ameasurement frequency of no more than 5 seconds.
• Measure and record UUT instantaneous power consumption with an accuracy of+/- 1.0 Watts and a measurement frequency of no more than 5 seconds.

INPUT VOLTAGE
The power supplied to the UUT shall be consistent with one of the options presented
below:
Table 1: Input Power Requirements

Input Voltage
Range

PhasesAC Input
Frequency Range

100-120 VAC RMS

147-63 Hz

180-240 VAC RMS

347-63 Hz

200-240 VAC RMS

147-63 Hz

380-508 VAC RMS

347-63 Hz

Test Procedure
ONLINE & NEAR-ONLINE CATEGORIESThe following test sequence shall be applied to systems in the Online and Near-Online
taxonomy categories.
Table 2: Test Sequence for Online & Near-Online

Phase

Workload% of Max
Sustainable
Performance

Preconditioning

Random
70% Read
30% Write

100%

8K

10 minActive “A”

Random
Read

100%

8K

10 minActive “B”

Random
Write

100%

8K

10 minActive “C”

Sequential
Read

100%

256K

10 minActive “D”

Sequential
Write

100%

256K

10 minENERGY STAR Data Center Storage
DRAFT Initial Data Collection Procedure

BlockSize

SustainedDuration2

Page 4 of 6Phase

Workload% of Max
Sustainable
Performance

BlockSize

Sustained
Duration2

Active “E”

Random
70% Read
30% Write

25%8K

10 minActive “F”

Random
70% Read
30% Write

80%

8K

10 minActive “G”

Random
70% Read
30% Write

100%8K

10 minReadyIdle

n/a0%

n/a30 minDeep Idle(Optional)3

n/a0%

n/a

10 minNotes:
1. Response Time for Online and Near-online systems during Active test phases
must not exceed 30 ms.
2. Each test phase must be of sufficient duration to exercise the entire storage
system and achieve stable system performance. Once stability has beenachieved, the measurement period begins and shall continue for the “SustainedDuration” specified in the table.
3. The Deep Idle test phase is included to allow storage systems to demonstrateadvanced power saving capability by placing one or more storage devices into a
reduced power state. Deep Idle should only be performed on systems which offera Deep Idle feature that may be enabled and configured by the system operator.
Storage systems which by design require a subset of storage devices to be in a
reduced power state and as a result cannot meet the 30 ms Response Timerequirement should be considered to be in the Near-online category.

REMOVABLE & VIRTUAL MEDIA LIBRARY CATEGORIESThe following test sequence shall be applied to systems in the Removable Media
Library and Virtual Media Library taxonomy categories.
Table 3: Test Sequence for Removable & Virtual Media Libraries

Phase

Workload% of Max
Sustainable
Performance

Preconditioning

Sequential
Write →
Rewind →
Read

100%

ENERGY STAR Data Center Storage
DRAFT Initial Data Collection Procedure

BlockSize

SustainedDuration5128K

10 minPage 5 of 6Phase

Workload% of Max
SustainablePerformance

BlockSize

Sustained
Duration5

Active “A”

Sequential
Write

100%

128K

10 minActive “B”

Sequential
Read100%

128K

10 minReadyIdle

n/a0%

n/a30 minDeep Idle(Optional)6

n/a0%

n/a

10 minNotes:
4. Response Time for Virtual and Removable Media Library systems during Active
test phases must not exceed 30 ms.
5. Each test phase must be of sufficient duration to exercise the entire storage
system and achieve stable system performance. Once stability has beenachieved, the measurement period begins and shall continue for the “SustainedDuration” specified in the table.
6. The Deep Idle test phase is included to allow storage systems to demonstrateadvanced power saving capability by placing one or more storage devices into a
reduced power state. Deep Idle should only be performed on systems which offera Deep Idle feature that may be enabled and configured by the system operator.

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