[email protected] 2001 1 EMC Performance John Popplewell ICL Distinguished Engineer...

AXIS 2001 [email protected]

EMC Performance

John Popplewell

ICL Distinguished Engineer

[email protected]


Disclaimer• EMC have two product ranges

– Symmetrix – Clariion

– This presentation is primarily about Symmetrix

• An EMC system is an intelligent piece of software controlling a cache, controlling industry standard discs.

• Two aspects to its performance– FC or Trimetra Controller Cabinet performance– EMC cache performance

• Outside the scope of this presentation


EMC Overview

• EMC models– Symmetrix 32 Gb cache– Clariion 0.5 Gb cache

• ICL processor models– DL & Nova – direct FC connect– SY - connect via ICL peripheral controller (SDS3)

• Clariion => DL & Nova• Symmetrix => SY & Nova & DL


EMC StorageWhat does it provide?

• Disc Storage– Guaranteed availability

• Symmetrix Raid 1 & Raid S*• Clariion [Nova & DL] Raid 1/0 – mirrored and striped (64 kb)

– Good performance

• Multi platform support within one box– Common storage– Flexibility - investment protection

• Fast data copying– Background volume copies (BCV’s)– Offline archiving

• Business Continuity– Remote mirrors (SRDF-Symmetrix Remote Data Facility)

[* Raid S not supported on VME]


EMC Symmetrix Connection to VME SY

SMARTfibre

VME Connection

Sym Manager

Mini Hub Mini Hub

Trimetra SDS Cabinet

Ctrl pair Ctrl pair

Mini Hubs (or use existing

SMARTfibre Hubs)

Channel Directors (CDs) for VME

connection (paired for resilience)

4 SCSIs per CD

SCSI

Remote Link Channel Directors (RLDs), for SRDF (paired for resilience)

A Controller-pair supports up to 32 Logical Volumes

SRDF links (dark fibre), external converters needed to use E3/ATM links etc

Sym Manager (usually on NT) used to control Symmetrix

VME System(s)

Groups of VME Logical Volumes

(mirrored for resilience) & their

(optional) BCVs

Symmetrix

CD (SCSI)

CD (SCSI)

CD (RLD)

CD (RLD)

Log Vol

BCV Copy

Node Node Node Node

VISA (via RDC)

Phone Home


EMC Symmetrix Connection to VME NOVA & DL

Fibre channel

VME Connection

IOP IOP

Channel Directors (CDs ) for VME

connection (paired for resilience)

Remote Link Channel Directors (RLDs ), for SRDF (paired for resilience)

SRDF links (dark fibre), external converters needed to use E3/ATM links etc

VME System

Groups of VME Logical Volumes

(mirrored for resilience) & their

(optional) BCVs

Symmetrix

CD (Escon)

CD (Escon

CD (RLD)

CD (RLD)

Log Vol

BCV Copy

Node Node Node Node

Phone Home

Switch Switch

IOPIOP


EMC Configurations

– Capacity

– Connectivity

– Performance

Any SDS3/EMC configuration must be addressed from the three points of:


EMC Symmetrix Model range

8430 8730

Minimum number of physical discs

8 16

Maximum number of physical discs

96 384

Type of disc 18GB , 36GB, 73GB

18GB , 36GB, 73GB


SDS3/EMC Capacity

• Work out the amount of filestore require to replace the existing discs

• EMC physical volume– 18, 36 or 73 Gb

– Nova Configured as 4 or 9Gb logical volumes

– SY Configured as 9Gb logical volumes

– DL Configured as 4Gb logical volumes

– Each VME 9 Gb logical volume contains ~ 8 Gb• VME is a variable block architecture, therefore 2048 bytes requires 5 * 512 byte fixed

blocks• Red tape, headers trailers etc.• Capacity is block size dependant


EMC CapacityEMC/CLARiiON Capacity (1 VME Volume)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

Blocksize

GB

EMC 512

CLARiiON 4GB

CLARiiON 9GB

SAT300

SAT300

CLARiiON (9GB)

CLARiiON (4GB)

EMC (512)

•0 2048 ` 10k


EMC Connectivity

Cache

Channel directors

Disc directorsx discs per bus (depends on Symmetrix type)4 buses per disc director

EMC view

4 SCSI per channeldirector

BUS


VME SY - EMC Connectivity

• EMC Symmetrix are connected to VME-SY via a Trimetra Controller cabinet

• Each TCC contains 4 controllers• Controllers are organised in pairs• A controller pair supports 32 9 Gb logical volumes• The EMC systems are configured with varying numbers

of channel directors.• Each channel director supports 4 SCSI interfaces.• Each controller pair requires two SCSI connections in

different channel directors.


VME SY - EMC Connectivity

• Use fully populated Trimetra Controller cabinets• No resilience benefit in configuring two cabinets with 1 controller

pair, rather than one cabinet with two controller pairsunless the cabinets are in different rooms

• Smartfibre recommendations– No more than 4 controllers per Smartfibre

• Same controller connectivity rules as existing VME controllers, i.e. a SDS controller can be attached to a single or multi-node system, or a partitioned system

• An EMC channel director can connect to more than 1 VME system.


SDS/EMC Performance

• SDS Controller performance

Type IOP’s Controllers /

controller cabinet

SDS Mk3 ~600 4

Depends a lot on the blocksize(above for reasonable response times, i.e. less than 30 msec response times for 2 Kb xfer)

• Safe figure is 250 IO’s second per controller

• 4 Controllers per Cabinet

• 64 spindles per cabinet

• Therefore, a safe figure is ~15 IO’s per second per spindle


Disc Performance

Machine SX SY SY DL Nova

Disc SA300T - 9Gb SDS3 EMC Clariion Denali Clariion -alpineRead Write Read Write Read Write Read Write Read Write

Single disc - 2Kb 530 230 800 650 1069 980 1285 1332Single disc - 16Kb 1630 2520 2090 3165 3045 3892 4344Single disc - 23Kb 3880 1660Single disc - 64Kb 5303 4226 6013 6221Single disc - 256Kb 5940 3600 7390 5640 6000 5550 7571 4931 9477 7111


SDS3/EMC Performance

• CAFS– 4 CAFS controllers per Trimetra Controller Cabinet– Searching speed is a function of hit rate, record size

etc.– Rates in Mb / sec

hit rate SDS3 SA300T & SA300

• Min 20% 2.56 3.4

• Ave 6.1 6.9

• Max 0% 6.6 7.5


EMC PerformanceDisc Gb Disc Index

SA100 1.43 2.06SA200 2.88 1.77SA300 (4.3) 4.3 1.99SA300 (9) 9.0 1.95SA150 2.15 2.25SA300T(9) 9.0 1.86SA300T(4) 4.0 2.08LY Disc (9) 9.0 1.63LY Disc (4) 4.0 1.80EMC (SDS3) 32 (36) 4.68 assuming 80 % cache hitsEMC (SDS3) 8 (18) 4.97 assuming 80 % cache hitsGI20 2.88 1.54GI30(4) 4.0 1.88GI30(9) 9.0 1.70ESS 0.65 4.34FDS20G 2.3 1.14FDS5000 1.27 1.00FDS2500 0.62 1.05FDS760 0.76 1.01FDS300 0.31 0.91

Mixture of serial, random and different block sizes


EMC Performance

• Benchmark results– Runtime

• Heavy IO ~30% of original time• Typically ~70% of original time• OCP dominant ~100% of original time

– BCV Establishment• Depends on number of drives etc.• Establish (measured)32 * 9Gb volumes ~ 75 mins• Establishment done in parallel• Therefore done 36 Gb in 75 mins• rate is 8 Mb/sec (Ultrafast SCSI nominal 40 Mb/sec)• Disc rate ~10 => 15 Mb/sec• Split BCV from 1st system and introduce into 2nd system ~ 5 mins


EMC Q&A’s

• Q1 Mainframe attach

– “Can a SDS controller attach to two VME Systems”

– While an EMC system can attach to more than one system, each SDS controller can attach to a single or multinode system - or a partitioned multinode system


EMC Q&A’s

• Q2 RAID

– Is RAID1 (mirroring) standard?• Yes

– Is RAID S supported• No


EMC Q&A’s

• Q3 VME / IDMS Duplexing or SRDF?

– Discuss !

•IDMS or VME•1 read and two writes through SDS3 controller•With single EMC frame, twice as much data in EMC cache

•EMC Mirroring•1 read and 1 write through the SDS3 controller

•Propose•VME Systems distributed < 2Km

•VME or IDMS plexing rather than EMC SRDF•Each site will have processors, Smartlans, Internodes etc•With EMC mirroring, 4 copies of data

•VME systems distributed > 2 Km•Use EMC SRDF•Need alternative system at remote end•Min of 3 copies of data, probably 4


EMC Q&A’s

• Q4 CAFS

– “Does CAFS work and what rate can we expect”

– Yes, CAFS works, low hit rate comparisons

Controller EMC RateSA300 7.5 Mb/secSDS2 4.7 Mb/secSDS3 6.6 Mb/sec


EMC Q&A’s

• Q5 Facilities

– SRDF (non sys discs) – BCV’s

– IPL – SRDF & Sys discs


EMC Q&A’s

• Q6 VME Release

– “What release of VME is required?”

– OVME2 onwards– EMC is SY only


EMC Q&A’s

• Q7 BCV issues

– Outside the control of VME– BCV’s of a total system are OK– Catalogue and FLF contain information– BCV’s of part of a system (application) are possibly

fraught with danger -think– Careful filestore design


EMC Q&A’s

• Q8 Hot spares

– “are these included in the limit of 96 or 384 discs physical discs?”

– Yes and No, • they are invisible to VME• however, the customer has to purchase the hot spares, so

beware if fully populating boxes• why buy them -- speedy availability


EMC Summary

• Disc Storage– Guaranteed availability (Raid 1 & Raid S***)– Good performance

• Multi platform support within one box– Common storage– Flexibility - investment protection

• Fast data copying– Background volume copies (BCV’s)– Offline archiving

• Business Continuity– Remote mirrors (SRDF-Symmetrix Remote Data Facility)

[**** Raid S not available on VME]

[email protected] 2001 1 EMC Performance John Popplewell ICL Distinguished Engineer...

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