LPAR Capacity Planning Update © Al Sherkow I/S Management Strategies, Ltd. (414) 332-3062 [email protected] Copyright©1993-2000, I/S Management Strategies,

LPAR Capacity Planning Update©

Al Sherkow

I/S Management Strategies, Ltd.(414) 332-3062

[email protected]

Copyright©1993-2000, I/S Management Strategies, Ltd., all rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written consent of the copyright owner. The OS/390 Expo and Performance Conference is granted a non-exclusive license to copy, reproduce or republish this presentation in whole or in part for conference handouts, conference CD, conference web site, and other activities only. I/S Management Strategies, Ltd. retains the right to distribute copies of this

presentation to whomever it chooses.

Session P12

Updated Presentation Available at www.sherkow.com/papers

©I/S Management Strategies, Ltd., 2000 2

Trademarks

• Trademarks, these may be used throughout this presentation– Parallel Sysplex, PR/SM, Processor

Resource/System Manager, OS/390*, S/390* are trademarks of IBM Corporation

– Other trademarks, that may be used, are the property of their respective owners

*Registered Trademarks


Goal and Objective

• Today's use of your resources– Visualization of LPARs– Visualization of Parallel Sysplexes– My experience: this is most difficult and

often misrepresents the true use of resources

• What will change• Preparing a plan

– Updating the visualization

Oct Announcements!

Dropped SomeBackground Slides!


• Consumption of Resources• Consumers of Resources• Growth of Business and Workload

– same problems and issues we’ve always had• magnitude of requirement• time of requirement

• Limits – usually hardware, but could be software,

database– batch windows– time for planned outages

What is Capacity Planning?

“Predictions are always tricky,

especially about the future”, Yogi

Berra


Important??

15Feb1999

Why You MayNeed CapacityPlanning -- It Reduces the constant need for upgrades It lets you better use idle capacity It allows better

management of hardware


Important, or Not?

21Feb2000

“Choose an architecture that can scale to at least 20 times what you really think you’ll need in six months? When was the last time anyone chewed you out for having too much disk-drive capacity?”


Resources Working Together

• Processors– Number of CPs– Memory– Channels and Links

• Coupling Facilities– Also have CPs, memory and links

• I/O• Keep Them Balanced


First, Is The Performance OK?

• What are the desired Goals for the workloads?

• Were the goals met?• What response time and throughput

were achieved?• If a goal was not met determine why

not?


LPAR Overview

Logical Partitioning PR/SM, MDF, MLPF

Operating SystemsOS/390A

OS/390BOther


Available Time on Physical System

Two Partitions Views of Available TimeOne RMF Interval

10 Minute RMF Interval2 CPs

0 200 400 600 800 1,000 1,200

Seconds of CPU Time

CICS TSO Batch STCs

Other PGs MVS PGN=0 Uncaptured Time Available

Partition PROD

Partition TEST

C92-2VU


LPAR Definitions

• The examples are a 5-way system with 3 partitions

• IBM, Amdahl or Hitachi does not matter for this discussion

LPAR Names Part A Part B Part CLogical Engines 3 3 1Processing Weight 50 40 10Share of Each Logical Processor 16.7% 13.3% 10.0%


Workload's Current Use

0

10

20

30

40

50

60

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Hour of Day


Current Use of the Physical System

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Hour of Day

Part C

Part B

Avail

Part A


Current Use of the Physical System

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

Hour of Day

Avail

Part C

Part B

Part A


Trend Important Partition

PLATFORM CAPACITY FORECAST

JANFEB

MARAPR

MAYJUN

JULAUG

SEPOCT

NOVDEC

JANFEB

MARAPR

MAYJUN

0

10

20

30

40

50

60

70

80

90

100

Month

Platform Utilization

LPAR SYS1Weight 75

AvailableLPAR CMC1Weight 15

LPAR TESTWeight 10

Test Partition

Weights

c9cap2e


Represent Engines as Columns

• All the physical engines support all the logical engines

• As the utilization of the physical box approaches 100% the processing weights are used

• LPAR capacity limited by number of logical engines

0

10

20

30

40

50

60

70

80

90

100

CP 0 CP 1 CP 2 CP 3 CP 4

Pe

rce

nt Part C 10%

Part B 40%

Part A 50%


0

10

20

30

40

50

60

70

80

90

100

CP 0 CP 1 CP 2 CP 3 CP 4

Pe

rce

nt Part C 10%

Part B 40%

Part A 50%

Make It Easier to Understand

Arrows Highlight the Logical pushpoint between Part A and Part C


Average Growth Over Time

0

50

100

150

200

250

300

350

400

450

02

/27

/19

94

04

/27

/19

94

06

/27

/19

94

08

/27

/19

94

10

/27

/19

94

12

/27

/19

94

02

/27

/19

95

04

/27

/19

95

06

/27

/19

95

08

/27

/19

95

10

/27

/19

95

12

/27

/19

95

02

/27

/19

96

04

/27

/19

96

06

/27

/19

96

08

/27

/19

96

10

/27

/19

96

12

/27

/19

96

02

/27

/19

97

04

/27

/19

97

06

/27

/19

97

08

/27

/19

97

10

/27

/19

97

12

/27

/19

97

02

/27

/19

98

04

/27

/19

98

06

/27

/19

98

08

/27

/19

98

10

/27

/19

98

12

/27

/19

98

MIP

S


Add Percentiles

0

50

100

150

200

250

300

350

400

450

50002

/27/

1994

05/1

5/19

94

07/3

1/19

94

10/1

6/19

94

01/0

1/19

95

03/1

9/19

95

06/0

4/19

95

08/2

0/19

95

11/0

5/19

95

01/2

1/19

96

04/0

7/19

96

06/2

3/19

96

09/0

8/19

96

11/2

4/19

96

02/0

9/19

97

04/2

7/19

97

07/1

3/19

97

09/2

8/19

97

12/1

4/19

97

03/0

1/19

98

05/1

7/19

98

08/0

2/19

98

10/1

8/19

98

01/0

3/19

99

PCTCQ3

PCTCP9

Average Usage

Notice the plateau, followed by a jump upwards


Add Max to Percentiles

0

50

100

150

200

250

300

350

400

450

500

02/2

7/19

94

05/2

2/19

94

08/1

4/19

94

11/0

6/19

94

01/2

9/19

95

04/2

3/19

95

07/1

6/19

95

10/0

8/19

95

12/3

1/19

95

03/2

4/19

96

06/1

6/19

96

09/0

8/19

96

12/0

1/19

96

02/2

3/19

97

05/1

8/19

97

08/1

0/19

97

11/0

2/19

97

01/2

5/19

98

04/1

9/19

98

07/1

2/19

98

10/0

4/19

98

12/2

7/19

98

Average Usage

PCTCQ3

MAX

PCTCP9


Consider: Averages or Percentiles?

• Averages Are Not Representative of Your Workload

• In an 8 Hour Shift With 15 Minute Intervals, There Are 160 Samples. 10%, 16 Samples, or 4 Hours Are Busier Than the P90 Value

• Many Would Argue, in Today’s E-world You Should Use P95, P99 or Even MAX

• Percentiles Represent the Peaks Better• But ... ... ... Percentiles Are Very Hard to

Explain to Anyone, Technical or Management


Do Peaks Matter?

e-Commerce Simple Intermediate Advanced

Peak/Average Volume 5x 20x 100x

Cost of Outage $1K $200K $20M


Waiting for CPU?

Top Line is Partition BusyBottom Line is PCTRDYWT


Waiting for CPU?

Top line Whole Box BusySpikey line PctRdyWtBottom line LPAR Busy


Change Across an Upgrade

0

10

20

30

40

50

60

70

80

90

100

07

/02

/19

95

08

/02

/19

95

09

/02

/19

95

10

/02

/19

95

11/0

2/1

99

5

12

/02

/19

95

01

/02

/19

96

02

/02

/19

96

03

/02

/19

96

04

/02

/19

96

05

/02

/19

96

06

/02

/19

96

07

/02

/19

96

08

/02

/19

96

09

/02

/19

96

10

/02

/19

96

11/0

2/1

99

6

12

/02

/19

96

01

/02

/19

97

02

/02

/19

97

03

/02

/19

97

04

/02

/19

97

05

/02

/19

97

Pe

rce

nt Mean of CPU

90th Percentile CPU

Mean of PCTRDYWT

90th Percentile of PCTRDYWT


LPAR Review

• Views of available time• One workload• One LPAR, One LPAR of many• Trending• Representing logicals on physicals• Averages, percentiles and peaks• Latent Demand: Pct Ready Wait


Why You Want Parallel Sysplex

• Up to 32 OS/390 images managed as one

• Single image to applications• Price/performance• Granularity• Scalability• Availability


Sizing Coupling Facilities

• Data Sharing CFs should have MIPS that are 8% of the total in the Sysplex, or 10% of the data sharing workload. Try for %Busy < 50%

• Memory: Try out the CF Structure Sizer on IBM’s website

• Links: for redundancy two from each image, watch power boundaries, and SAPs. Monitor RMF to determine if more are needed


Recovery Issues

• Avoid Single Points of Failure– Two CFs, two CPs in each CF, two Sysplex timers,

multiple links, couple data sets on separate DASD subsystems

• Build failure-independent configurations• Cannot rebuild ISGLOCK if left “system” is lost

MVS A CF1

MVS CMVS B CF2 MVS D

ISG

LOC

KXISGLOCK is for GRS Star


What Does It cost?1

• CPU effect varies based on– data sharing workloads

• how much of system• access to shared data

– type of hardware for Links, CFs and CPUs– number of images, each adds about 1/2%

• System Level– resource sharing: 3% more– data sharing

• stress testing: 15% to 20%• typical production: 5% to 11%


What Is Making Decisions?

• Two Sysplexes via Their 7 WLMs

• Three Partitioners• Who sets the capacity?

– The site through # of LPs and weights

– The site through Goals– The partitioner does not

know your goals– The WLM tries to satisfy

your goals• may be limited by # of LPs

PROD 3

PROD 1 TEST 1 TEST2

LEGACY 2

PROD 2

LEGACY1

2PlxOn3


What Can Push?

• 3 physical CPs, 2 LPs assigned to TEST 1 with weight of 33%, 3 LPs assigned to PROD 1 with weight of 66%

• Can the Parallel Sysplexes move the line, or only the partitioner?

PROD 1 TEST 1

2PlxOn3 UpperLeft


What Can Push (IRD)?

PROD 3

PROD 1 TEST 1 TEST2

LEGACY 2

PROD 2

2PlxOn3 IRD

LEGACY1

LPA

R C

luster

LPA

R C

luster

• IRD Provides LPAR Clusters

• WLM talks to PR/SM

• z/900, z/OS in z/Architecture mode

• Optimizes CPU and Channels across LPARs


IRD-Channels

• Channels– Dynamic Channel-path Management

• Monitors I/O to LCUs• Can Add or Remove Paths to an LCU• Monitored with I/O Velocity

100* (device connect)/(device connect + channel pend time)

• Managed Channels Must Go To Switch• Managed Channels Available to Only One LPAR

Cluster


IRD-Channels

• Channels– Channel Subsystem Priority Queuing

• z900 Basic or LPAR mode• z/OS sets this based on Goal Mode Policies

– different calculation than WLM’s I/O priorities– User sets up to 8 different values

• If 2 or more I/O requests are queued in the channel subsystem the CSS microcode honors priority order


IRD-CPU Management

• Manages Processor Weighting and Number of LPs in an LPAR Cluster by Goal Policies

• Sum of Partitions’ Weights is Viewed as a Pool, Controlled by the Site

• Value– Engines run with less interference because

fewer time slices– Reduced overhead fewer LPs– Let’s PR/SM understand the Goals

• New data: Partition min, max and avg weight, time at min and time at max


IRD-CPU Management

• Clustering Does Not Communicate Between Different Parallel Sysplexes

• A Single Parallel Sysplex Can Have LPAR Clusters on Multiple CECs

• A Single CEC Can Have Multiple LPAR Clusters Belonging to Separate Parallel Sysplexes


IRD-CPU Management Controls

• WLM CPU Management Functions can be Enabled/Disabled on an LPAR Basis

• Minimum and Maximum Partition Weight

• Partition Weight is Renamed to “Initial Partition Weight


What Can Push?

PROD 3

PROD 1 TEST 1 TEST2

LEGACY 2

PROD 2

LEGACY1

2PlxOn3 Utilization Color


What Can Push?

PROD 3

PROD 1 TEST 1 TEST2

LEGACY 2

PROD 2

LEGACY1

2PlxOn3 Utilization Color


Engine Allocation

WORKLOAD DEF’NPROD 8.0TEST 3.0LEGACY 2.5AVAILABLE 0.0Total 13.50

0

0.25

0.5

0.75

1

1.25

1.5

1.75

2

UL CP 0 UL CP 1 UL CP 2 LL CP0 LL CP1 R CP 0 R CP 1 R CP 2 R CP 3

TEST 2

PROD 3

LEGACY 2

PROD 2

LEGACY 1

PROD 1

TEST 1


Average Utilization/Available

WORKLOAD DEF’N UsagePROD 8.0 5.5TEST 3.0 2.25LEGACY 2.5 1.75AVAILABLE 0.0 4.0Total 13.50 13.50

0

0.25

0.5

0.75

1

1.25

1.5

1.75

2


AVAILABLE

TEST 2

PROD 3

LEGACY 2

PROD 2

LEGACY 1

PROD 1

TEST 1


Capacity for Handling Peaks

WORKLOAD DEF’N Usage PROD PeakPROD 8.0 5.5 5.5TEST 3.0 2.25 2.25LEGACY 2.5 1.75 1.75AVAILABLE 0.0 4.0 0.0PROD PEAK 0.0 0.0 4.0Total 13.50 13.50 13.50

0

0.25

0.5

0.75

1

1.25

1.5

1.75

2


AVAILABLE

PROD PEAK

TEST 2

PROD 3

LEGACY 2

PROD 2

LEGACY 1

PROD 1

TEST 1


Trend Similar to LPAR

pstrend

PARALLEL SYSPLEX FORECAST

JANFEB

MARAPR

MAYJUN

JULAUG

SEPOCT

NOVDEC

JANFEB

MARAPR

MAYJUN

0

10

20

30

40

50

60

70

80

90

100

Month

Sysplex Utilization

PRODAvailable

LEGACY TEST


Software Pricing

• z/OS, z/900– Charges Based on LPAR Capacity– New External: Defined Capacity

• Rolling 4-hour average is limited by “Defined Capacity”

• Too Much Demand Leads to a “Soft Cap”– Can Run in Exception Mode!

• Records are Generated– White Space

• Can Have Engines Without LPARs• Available for Spikes, Handled through 4-hour

rolling average


Software Pricing: Why White Space5

40 40 4040404040

40 40 40 40 40 40

LPAR2limit: 3*40

= 120 MSUs

LPAR1limit: 6*40 = 240

MSUs

CICS WorkloadDB2

Workload

• Limit of Capacity is # of LPs or Weight In 100% Busy CEC

zSeries 280 MSUs

404040


Software Pricing White Space5

40 40 4040404040

40 40 40 40 40 40

WhiteSpace

55 MSUs

LPAR2defined75 MSUs

LPAR1defined 150

MSUsCertificates

CICS 225MSUsz/OS 225 MSUsDB2 75 MSUs

CICS WorkloadDB2

Workload

• Sum of LPARs Must Be Less Than Phys Box

• White Space is Not Defined, It is “Left Over” by Your Configuration

• Must Use LPARs

zSeries 280 MSUs


Summary

• LPAR– Capacity controlled by # of CPs– Flexible to 100% busy– WLMs do not talk to the partitioners IRD– Capacity on Demand may be writing on the

wall• Parallel Sysplex

– WLMs in separate Sysplexes do not talk to each other

– Your Sysplexes have goals that must be managed by you

– Handling Peaks is more important than ever!


Al Sherkow(414)332-3062

[email protected] www.sherkow.com

Questions?

1. King, Gary. OS/390 Conference Session P15. Oct99.

2. Kelley, Joan. Many Coupling Facility Presentations

3. IBM’s Parallel Sysplex website: www.s390.ibm.com/products/pso

4. IBM eServer zSeries 900 Technical Guide. Oct2000. SG24-5975

5. Workload License Charges & IBM License Manager (Expo Oct2000)

“Statistics are merely numbers and have no control over actual events.” PBS, Savage Planet, Storms of

the Century 06/17/2000

Documents

LPAR Capacity Planning Update © Al Sherkow I/S Management Strategies, Ltd. (414) 332-3062 [email protected] Copyright©1993-2000, I/S Management Strategies,