ssn08 san best practices

8/13/2019 sSN08 SAN Best Practices

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SAN Best Practices

Jim Blue

© 2011 IBM Corporation


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IBM Systems Technical University – Prague, Czech Republic, 4 – 7 April, 2011

What will be covered

rc ec ure

Zoning

Fabric

Stora e

High availability

ange managemen

Solution-centric



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rc ec ure

What is the purpose of the SAN?

How is the SAN supposed to help the business?

How critical is the data within the SAN?

a es gn an wea opera ona prac ces are

ingredients for failures



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rc ec ure: y s mpor anStorage networking architecture may benefit the organization but you

must remember there are always trade-offs.

Goal Trade-off

High availability Needs redundant components / higher costs

Performance More equipment / higher costs

Security Monitoring requirements and reduced ease of use

Scalabilit Im act on availabilit and costs

High application throughput Other applications impacted


,


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Zonin : What is it and Wh use it?

Partition the SAN in logical groups of devices

Enables secure sharing of SAN resources

Optimize SAN resources and improves workload

balance

Limits the impact of failing devices

Adds flexibility to meet the needs of different end-users

Use LUN masking in conjunction with zoning; it is not a

re lacement for zonin



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Zonin : Methods

No zoning (worse case)

Zone by operating system

Zone by application

Zone by cluster groups

Zone b sin le initiator ort best scenario


Never use WWNN for zone definitions!!!


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Zonin : Namin

Consistent naming scheme for all components

Use meaningful names

Should define who, what, where and how Location

Server

Server port

Fabric

Example: PilRd_SQL12_ed74_DS8K1_1132_A

Location_server_HBA_storage_storage port_fabric



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Zonin : Se aration of traffic t es

Would you share tape and disk devices on same SCSI bus?

epara e ss m ar s s orage sys ems

Keep FCP and FICON separate

Reduces impact range of RSCNs

FICON does not need it



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Zonin : Multi athin

Works on the host system with multiple paths to thes orage sys em

Presents only one view of a logical volumeFail-over recovery

It IS possible to have too many paths

Too many paths will degrade overall performanceMore ports does not equal N x bandwidth increase

(Bandwidth increase depends on IO size but typically ranges from1.4 to 2.9 times increase when going from 1 to 4 HBAs)



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Zonin : Im lementin chan es

If available, use automated tools to verify proposed

changes

Make changes from the same switch

core-e ge a r c es gn, use a core sw c

Introduce changes during low I/O times

redundant fabric(s)

Approximately 3-5 seconds per active port

Remove zoning items not in use

Understand the default zone policy (deny or permit?)



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Fabric: Consistenc is the word

Naming schemeServers e.g. SQL12

Storage devices e.g. DS8k_1Port descriptors e.g. SQL12_ed74

Code/firmware levels on similar devicesCabling

Labels and fully documented

Use cable guides

o no m x ca e s zes or ype

(62.5 micron and 50 micron) (OM-2 and OM-3)

Limit use of patch panels per cable run



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Fabric: Confi urations

Save device configurations before making any changesDo not store on SAN-attached storage

Fall-back mechanism

Version for the device

Another version which is human readable



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Fabric: Ex ansion

Use planning tools if available

Consult vendor interoperability matrices

If in doubt, open a proactive service ticket with vendor andask questions during the planning stage

Manual method: use number of active ports from the

Will the infrastructure need to grow?

Locally (expansion from growth and/or consolidation)

Distance (business continuance or disaster recovery)



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Stora e: Im lementation

Use stable code/firmware versions

Enable open WWPN access points on storage(if supported on the storage system)

Data replication?Don’t use the same storage port for host connections and

data replication

Do not share SVC and host traffic on the same storagedevice ort

Provide for remote access?

Your Administrators and vendor’s support personnel

v u u uServer definitions

Storage to server mappings (LUN masking)



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Stora e: Workload balance

Follow suggested fan-out ratio for storage device ports

If storage system has multiple ports, spread the

workload evenly

. .

Preferred paths

Failover scenarios

Boot from SAN scenario

Use available management tool to monitor workloads

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Must consider workload for performance

IO per second (for transaction workloads)

MB per second (for throughput workloads) Avera e size KB er IO

Read/write ratio

Sequential or random

High capacity disk does not fit all situations

Remember: Need to have similar info for ALL hosts, applications and

existing storage arrays



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Beware of rank and/or RAID array loads

Use number of data drives to develop max load factor

Do not include parity and/or hot sparesDisk s eed determines workload factor

Rule of thumb (per disk drive). : – ps

10K RPM: 120 – 150 IOps

15K RPM: 165 – 200 IOps

SSD: 1500 IOps

(sequential read traffic will be less due to cache and pre-fetch)



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Stora e: How much is enou h?

Just-in-case provisioningExcess ca acit waitin to use

Typically higher operating expenses

Just-in-time rovisionin Add required capacity and allocate immediately

Requires very good planning

Either method may require data relocation

Understand the traffic pattern for a new project



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g ava a y: unc ona es gn

o s ng e po nt o a ure

Very Small: Single or cascaded

Small: meshe um: par a mes

Large: core-edge

Keep high bandwidth consumers local

Storage and host(s) on same switch (core)



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g ava a y: unc ona es gnBeware of ISL oversubscription (maximum 7:1 to 10:1)

(need to understand traffic patterns at higher ratios)

Use vendor’s suggested oversubscription ratio for inter-

(don’t exceed available bandwidth – fibre channel or LAN/WAN)



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Hi h availabilit : Servers and Clusterin

Redundant components in the servers

Beware of multiple applications with the same purposeCurrent device driver levels and O/S fixes

HA cluster is not the same as workload balancing

cluster or grid cluster

Clusters shift the focus from the server hardware to

the application

Cluster scale – local or dispersed?



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g ava a y: or s r u on an res encyUsing trunking or port-channels?

prea e oa poss e

Servers connect to different switches or line modules

Spread storage system connections across

multiple switches and line modules



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Chan e mana ement: What is it and wh use it

Assess the risks of all proposed changes and decide if the

C/M does not have to be served by a dedicated application

C/M is a methodology that works for the business (end-

users) and IT team (implementers)When is a change not working and what actions are

needed to back-out / stabilize? (clear guidelines are a MUST!)

Use all available resources: Readme files, vendor, test

environment


Verify all dependencies are known and in-place


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Chan e mana ement: Documentation

Configurations of all devices (before and after)

Updated as part of the change process

Be able to explain decision for the changeDocumentation must be sufficient to build the SAN

environment from “clean slate” ( never stored on the SAN )

be simple and clear



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Chan e mana ement: Im lementation

Use out-of-band communications for management

ever use e au passwor s

If monitoring capability includes performance sampling,ca ture erformance baseline metrics re ularl

Establish threshold alerts for ISLs and high bandwidth edge

devices (varies from 66% to 75%) Automate processes where possible

Use dedicated management LAN or firewall protection

from all key systems for troubleshooting and recovery

(If in doubt, collect data anyway ASAP)



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ange managemen : agrams

Can be created by a

variety of methods

n y a po n - n- me

image of the SAN

environment

Should show how and

where key components

are interconnected



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Chan e mana ement: Watch out for …

With many management applications, keep managed

environments to a minimum. Whether h sical or

virtual SANs

Provision for what is needed plus reasonable growth

Keep individual changes simple

Administrator roles assigned

Clear admin roles: Does HBA firmware/device driver

u dates belon to server or SAN administrator?

Before any change, verify all redundant paths are



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Solution-centric: Consistenc

Consult interoperability matrices and vendor support

Use NTP (network time protocol) where possible or set

device clocks to single time zone

uppor personne w an you

Quicker resolution of problems

Know when all ma or a lications are scheduled to run

Data backups

Data warehousing

Collect performance metrics on a regular basis

Naming convention



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Solution-centric: Mana ement a lications

Tools for complex environmentsRun on standalone s stems with internal stora e – do not use

SAN-attached resources

Uses standard interfaces/protocols

-

Assist the administrator with:

Change management

Configuration

Provisioning

Automation of routine tasks and procedures



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Solution-centric: Securit

Two types of security: data and access

Passwords

How strong is strong enough?

Save in a secure back-up repository

Are roles or levels of authority in use?

Data security includes encryption. Is there a

fallback mechanism to recover encrypted data or



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Solution-centric: General

If at all possible, create and use a testbed SAN

env ronmen

Time-sharing of development environment for

Changes to business-critical applications and

services chan es should be verified before roll-out

to the production environment

Develop a regular plan for code and firmware targetlevels for future upgrades



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Solution-centric: General



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What was covered

rc ec ure

Zoning

Fabric

Stora e

High availability

ange managemen

Solution-centric



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Special Session – s99GE

Storage Roundtable Congress Hall III Thursday, April 7

305 RAMAC

STORWIZE V7000

Bring your storage questions and ask the experts.Learn about IBM’s Storage roadmaps.

© 2011 IBM Corporation35

Non-disclosure form required!


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THANK YOU!



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IBM TotalStorage: SAN Product, Design, and Optimization Guide, SG24-6384

Brocade SAN Architectural Brief Brocade White Pa er GA-AB-023-00

Building and Scaling Brocade SAN Fabrics, Brocade Pub 53-0001573-01

Scalable Fabric Design – Oversubscription and Density Best PracticesCisco white paper ETMG 203154—LSK 05/04

, -

IBM TotalStorage DS8000 Series: Performance Monitoring and Tuning, SG24-7146

Veritas Dynamic MultiPathing (DMP) for Windows, Symantec White Paper, 07/2005

Brocade Multiprotocol Router SAN Design Guide, Brocade Pub 53-0000552-01

SAN Volume Controller: Best Practices and Performance Guidelines,SG24-7521

IBM TotalStorage Enterprise Tape: A Practical Guide, SG24-4632

Virtualization in a SAN, IBM Redbooks Paper REDP3633

VMware Virtual File S stem: Technical Overview and Best PracticesVMware white paper

HP StorageWorks: SAN Design Reference Guide, H-P Pub AA-RW86D-TE

ssn08 san best practices

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