Microsoft Exchange 2013 Sizing – An Information
Behind the Guidance
About Me – Charles Derber
 Have been working on Microsoft Messaging for ALMOST a Decade
 Experienced on Planning / Implementing / Migrations / Designing / Consulting for Messaging
Enterprise & Hosting Solutions
 Also experienced on Multiple Messaging Vendor like Microsoft, IBM, Linux etc. but gained
much expertise in “Exchange” due to exposure and interest on Microsoft Products
 Speaker @Mumbai IT Professional User Group & I do blog @
http://charlesgate86.wordpress.com
Agenda
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In the beginning – Road to Sizing
Architectural Changes Impact on sizing
Sizing Server role specific Deep drive - MBX / CAS / Active Directory
Exchange Roles Sizing – Storage / Networks / Virtualization / Hardware
Exchange 2013 Sizing tools
Considering Exchange 2013 Virtualization
Sizing – Demo
Sizing is both a “Science” & an “Art” form.
Guidance
 Where it is coming from? – Pre-release environment!!
 (Test labs / Dog Food(emails are used in a way where it is not intended to
use / Yes multi profile) / MSIT / Customer / Field work)
Resources
 TechNet / MS Exchange Team Blog / Experts Blogs
 Third Party Tools
What is not possible…?
 Doesn’t cover everything because it cannot cover everything - but will
provide some base line to start with 
 Third party solution - BB / SMTP Relay / Applications
 Third Partner dependent - Every one has different architect / functionality
 Hardware support
 Needs lab testing for your environment / consider failure domains - High
Availability
6 STEPS SIZING PROCESS
6. Finalize
Design
5. Consider
Impact
4. Input Profile
Data
1. Read
Guidance
2. Collect Data
3. Define
Constraints
Sizing Process
1. Read / Understand sizing, scalability, capacity guidance
 Documentation @TechNet / Exchange Team Blog
2. Collect Data on existing deployment
 User profiles (message sent + received per day)
 Average message size
Sizing Process
3. Define constraint
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No of database copies
Backup requirement
Storage architecture
Safety Net duration
Virtualization
Growth Plans
3rd Party Products
Sizing Process
4. Input profile data and design constraints into calculator tool
 Always use latest calculator
5. Consider impact of various option provided by results via Calc.
 Cost
 Rebuilt times
 Impact on High Availability
Sizing Process
6. Finalize Design
 Storage calculator provides configuration scripts
 Archive the calculator as documentation of the sizing process
Architectural Changes / Features
Exchange Server Roles
CAS Stateless – OWA / OAB / OA / EAS / EWS / Mail Flow
MBX – PF HA / Managed Store / IOPS / Safety Net & Others
Balanced use of Hardware – CPU / Memory / Disk
Minimum Systems Requirement
 RAM
8GB – Mailbox or Multirole/Mailbox+CAS
4GB – CAS
 CPU
Follow published OS guidelines
 Disk Space
30GB
RAID vs JBOD, DAS vs SAN, Oh My!
Where is your personal/precious email – JBOD
 Google email account is stored without RAID
 Microsoft's Office 365 cloud service utilizes JBOD for storage
 Microsoft's own internal deployment of Exchange 2010 has over 180,000 users
on a JBOD infrastructure
 Microsoft's TerraServer uses JBOD to store all of the data presented through
that web site
 Microsoft therefore recommends that if you are considering utilization of drives
in a JBOD architecture that you do choose to do so with the 7.2K RPM SAS drives
rather than SATA
What Storage should I choose ?
 Even I can't tell you which storage architecture to choose
 Microsoft supports SAN and DAS+RAID along with DAS+JBOD because no
single storage architecture is right for every customer out there.
 Unless you are in a situation where money is no object and will continue
to be no object, you must seriously evaluate the storage solutions
available to you
Sizing Exchange 2013
– Mailbox Role
Mailbox Role - Impact
 Increased resource usage
 Cache sizing is different
 New content indexing architecture impacts performance
 By default UM enabled on MBX
 Managed availability
Mailbox Role - Storage
 Mailbox Database, content indexes, log space
 20% database overhead is now 0%
 Content Index size is now 20% of EDB
 Plus space for additional index set per volume (master merge)
 Note that impact of space for master merge is reduced with multiple DBs
per-volume
Mailbox Role – Storage Bandwidth
 BDM in 2013 now consuming ~1MB/sec/DB copy, significant reduction from
2010
Mailbox Role – Transport Storage
 Transport queue database takes advantage of ESE IO improvements to reduce
IOPS
 Microsoft production observations show ~1 DB IO per 75KB message
 Low IOPS suggest that placing transport queue on system/install volume is
now feasible in many scenarios
 Significant transport throughput benefit seen from a protected write cache
disk controller, set to 100% write cache
 Transport capacity requirements include queue and Safety Net
Mailbox Role – IOPS
 Exchange 2013 reduced IOPS requirements (~33% reduction compared to
2010)
 Checkpoint depth is now consistent for all DB copies, so IOPS requirements
are the same
Mailbox Role – CPU
Messages sent or
received per mailbox
per day
50
100
150
200
250
300
350
400
450
500
Mcycles per User,
Active DB Copy or
Standalone (MBX
only)
2.13
4.25
6.38
8.50
10.63
12.75
14.88
17.00
19.13
21.25
Mcycles per User,
Active DB Copy or
Standalone (MultiRole)
2.66
5.31
7.97
10.63
13.28
15.94
18.59
21.25
23.91
26.56
Mcycles per User,
Passive DB Copy
0.69
1.37
2.06
2.74
3.43
4.11
4.80
5.48
6.17
6.85
Note: Baseline platform for CPU guidance changed in 2013. Mcycle requirements in 2010 and 2013 cannot be
directly compared.
Mailbox Role – CPU
 Hyperthreading (SMT) – Fantastic Technology increases CPU throughput –
DONT USE IT…!
 .Net framework allocates memory per core heaps
 Significant impact to some Exchange service memory footprints
Mailbox Role – Memory
 Memory on the Mailbox role sized based on ESE
cache requirements
 Cache requirements have remained constant from
2010
 Overall cache sized to 25% of RAM, so guidance
(based on total system memory) is 4x of 2010
cache sizing recommendation
 Multi-role servers require additional memory for
CAS based on user concurrency during worst-case
failure
Messages sent or
received per
mailbox per day
Mailbox role
memory per active
mailbox (MB)
50
100
150
200
250
300
350
400
450
500
12
24
36
48
60
72
84
96
108
120
Mailbox Role – Memory
 Memory is allocated within heaps
 .NET garbage collector has different “modes” which optimize for different allocation
scenarios
 Workstation GC
 Uses common heap and cleanup process (can be concurrent or not)
 Server GC
 Allocates a heap and thread per logical proc
 Server GC results in dramatically larger memory requirements at rest when SMT is
enabled
Mailbox Role – Memory
 Best practice to install KB 2803754 or 2803755
 http://support.microsoft.com/kb/2803754 (Windows Server 2008 R2)
 http://support.microsoft.com/kb/2803755 (Windows Server 2012)
 Reduces memory consumption in each store worker
No impact to sizing guidance
Memory is available for use by other processes
 Decreases CPU spent in .NET garbage collector
 Benefits Mailbox & multi-role
 Enable by installing hotfix and setting regkey:
HKLM\Software\Microsoft\.NETFramework\DisableRetStructPinning (REG_DWORD) = 1
Mailbox Role – Network
 Seeding of multiple database per disk may require increased bandwidth
between servers
 Avoid bottlenecking on network
 Plan for reseed operations, particularly in JBOD deployments
 10GB Ethernet expected to become more common for Exchange
infrastructure
 Cost has dropped, many customers are standardizing on 10GB Ethernet
in their datacenters
Mailbox Role – Unified Messaging
 UM is sized using a concurrency model – you cannot have a dedicated server
role as UM
 Plan for a maximum of 100 concurrent calls per server
 Note that UM in 2013 is a component of the Mailbox role, may need to
adjust user distribution to optimize UM utilization/concurrency
 Voicemail transcription is a heavy consumer of CPU
 Plan for 1 CPU core per concurrent transcription If server is CPU starved,
voicemail transcription may be skipped (voicemail delivered without
transcription)
Sizing Exchange 2013
– CAS Role
CAS Role - Impact
 Low resource utilization makes multi-role deployment (or virtualization)
attractive
 CAS is intelligent director of traffic work
 Shift of processing resources from LB layer to CAS may negate new
resource demand
CAS Role – Processor
 CAS CPU is sized using a percentage of Mailbox CPU active user requirements
 2013 CAS requires 25% of Mailbox active-user mcycles, down from 75% in
2010
 Given significant reduction, ensure that enough CAS servers are deployed to
handle failures and provide high availability
CAS Role – Memory
CAS memory is sized using a simple formula of 2GB + 2GB per-CPU core.
The per-core value assumes utilized CPU cores at peak (worst case failure), so
this can get a little complicated
total user count
× Mailbox mcycles per−user × 0.25
CAS
server
count
in
worst
case
Per−server CAS memory = 2GB + 2GB ×
mcycles per−core
Kemp Hardware Load Balancer & MS Exchange
Why Hardware Load Balancer…?
 Microsoft Recommends
 Service Aware, Pre-auth, SSO for Exchange & Lync
 Evenly distributes load(Http/Mapi{Exchange 2010}/Https) between CAS
servers
 CA-FE now a stateless proxy server
 SSL Acceleration & Reverse Proxy
 Site HA & Geo Auto-failover
 “Kemp HLB” is Microsoft Certified & Few others too!!!
 Engineered especially for Microsoft Exchange & Lync
 Lync / Application servers load balances too not limited to Exchange
 Play around with Trial Virtual Load Balancer from Kemp to experience the
functionality and its features.
Active Directory
 Recommend deploying 1 AD GC core for every 8 Mailbox cores handling
active load (assuming 64-bit GCs)
 Size memory such that the entire NTDS.DIT can be contained within RAM for
optimal query performance
Exchange 2013 Diagnostic & Perfmon
 Logs:
 Microsoft\Exchange Server \V15\Logging\Diagnostics\DailyPerformanceLogs folder
 Microsoft\Exchange Server\V15\Logging\Diagnostics\PerformanceLogsToBeProcessed
 MS Exchange Health Management Service
 Works towards assessing the health of Exchange components – OWA / EAS / EWS /
ECP
 It also captures information about activities such as the Calendar Repair Assistant,
Mailbox Assistants, Mailbox Replication service, Migration service, OAB generation,
and so on – V15\Logging root
Exchange 2013 Diagnostic & Perfmon
 Most of the logs generated in CSV which are helpful in troubleshooting issues – at
times root cause.
 It fills the Exchange drive when not monitored – use data collector set to create
resource policy and delete or follow Removing Old Exchange 2013 Log Files
 Diagnostic logging – 70 New Added & 81 Old Removed
 Removal of events for Public Folders and the addition of Front End Transport server
events seem to be the biggest change. The ExchangeSA\OALGenerator one,
commonly used to troubleshoot Offline Address Book issues, has been removed as
well
Exchange 2013
- Sizing Tools
Sizing Tools – Exchange Role Calculator
 Role Requirements Calculator turns published sizing guidance into a
modeling tool
 Try out various failure scenarios
 Understand the impact of different hardware & storage choices
 Provides scripts for DAG, database & copy creation
 Many new features
 CAS sizing
 Transport storage sizing
 Multiple databases per-volume (JBOD) support
 High availability architecture improvements
http://aka.ms/E2013Calc
Sizing Tools – Exchange Role Calculator
Sizing Tools – Exchange Profile Analyzer
 Helps administrators collect estimated statistical information from a single mailbox
store or across an Exchange Server organization
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Can only be run on Exchange 2003(SP2) & 2007
Exchange View-Only Administrator permission to run
Run during non-business hours to avoid performance issues(on CAS) if any
Improve capacity planning method
Sizing Tools – Exchange Profile Analyzer
Sizing Tools – Collectlogs.vbs
 Calculate Exchange transaction logs generated for each hour in the day
 A simple VBS script that will collect all files in a folder and output it to a log file
 Use Task Scheduler to execute this script at certain intervals in the day (e.g. every 15
minutes)
Sizing Tools – EmailStatistics.ps1
 Script parses messaging tracking logs of your Exchange Servers and then
tabulates the information into a CSV file
 Demo
Messages Received per Mailbox Per Day = Received Total
Messages Sent per Mailbox Per Day = Sent Unique Total
Average Message Size = Average of Received MB Total & Sent Unique MB Total
Sizing Tools – Processor Query Tool
 Quickly look up SPECint benchmark for a particular processor type
 Takes average across multiple vendor submissions
 Provides specific value to insert into Role Requirements Calculator
http://aka.ms/ExProcQueryTool
Sizing Tools – Jetstress 2013
 Jetstress 2013 released March 2013
 Validates that the physical deployment is capable of meeting specific performance
requirements
 Validates that the storage design is capable of meeting specific performance
requirements
 Finds weak components prior to deploying in production
 Proves storage and I/O stability
http://aka.ms/Jetstress2013
Sizing Tools – Jetstress 2013
 Jetstress is dumb tool that is used worldwide by thousands of Exchange
professionals
 When the Jetstress test reports a failure, Jetstress has not failed
Windows Operating System
Hardware
Reporting and Verification
Extensible Storage Engine
(ESE)
Background Database
Maintenance
Thread Dispatcher
Transactional I/O
Background Log Checksummer
Offline Log & Database Checksummer
Device Drivers
Auto tuning
Storage Subsystem
Windows I/O Manager
Jetstress Application
Performance Data
Windows Performance Counters
Sizing Tools – Exchange Client Bandwidth Calculator
 This Calculator has been designed to profile the network bandwidth
requirements of both Exchange on-premises and Exchange Online (Office
365) workloads.
 Hub site consolidation planning
 Exchange service externalisation planning
 Cloud requirements planning for Exchange Online (Office 365)
 Demo
Exchange 2013 – Virtualization Sizing
 Sizing methods for Exchange 2013 for physical and virtual hardware is the same
 However you need to consider the impact of a shared virtual infrastructure
 ~10% for Hyper-V (follow vendors guidance for other hypervisors)
 Co-locating Exchange with other virtual machines and workloads
 Use resource reservation options to ensure that Exchange gets what it needs
Exchange 2013 – Virtualization Supportability
 Supportability –
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Windows Server 2008 R2
Hyper-V Server 2008 R2
Windows Server 2012
Hyper-V Server 2012
Third-party hypervisors (SVVP)
 Exchange Roles
 Both Exchange 2013 roles supported for virtualization
 Live migration & Host based clustering is supported
Exchange 2013 – Not Supported
 Dynamic Memory
 Memory over commit / CPU over subscription
 Hyper V snapshots
 Differencing / delta disk
 Apps on the parent OS
Exchange 2013 – Not Supported
Hyper-V replica
• Replica provides DR for “any” VM via log shipping to a remote hypervisor
• Use Data Availability (DAG) to obtain better HA & DR with Exchange 2010 &
2013
• Replica makes sense for apps that don’t have DR capability built-in to the
product
Windows Azure Infrastructure Services, AWS or similar
Exchange 2013 – Dynamic Memory Impact
RPC Averaged Latency
Available Bytes
60
6E+09
50
5E+09
40
4E+09
30
3E+09
20
2E+09
10
1E+09
0
0
Questions…?