IBM Systems magazine, IBM Z - May/June 2020 - 37

transaction per second (TPS),
which averaged 37,230 for SCSI
disks and 33,632 for DASD. The
TPS for SCSI disks is 10% better
than ECKD disks.

Skills and Existing
Investments
Other aspects to consider when
choosing a storage option
are available skills, current
processes, existing investment,
ease of management and cost.
If your organization has strong
distributed skills and investments,
using SCSI disks is a wise choice.
If you have strong IBM Z skills
and investments, you might be
more inclined to favor DASD. FCP
and SCSI don't integrate with IBM
GDPS® and IBM HyperSwap-
so, if you're invested in these
technologies for backup and
disaster recovery, then FICON
AND DASD would be a good option.

The Choice Comes Down to
Existing Investments
There's much to consider when
choosing between FICON and
DASD or FCP and SCSI for Linux
on IBM Z (see Table 2, page 36).
No one option is always better
than the other. Performance
between FICON and FCP is on par
when using zHPF. SAP doesn't
provide substantial performance
advantages for FICON devices.
The emulation overhead of FICON/
DASD for Linux on Z-while
measurable-may or may not have
a real effect on storage capacity.
Choosing a storage option comes
down to existing investments
in either architecture, available
skills, and administrative and
backup processes.

Application Tier Considerations
for Moving to the Cloud or x86

W

ith more enterprises
moving to the cloud or
x86, traditional IBM
z/OS® applications are being
examined for deployment on the
cloud or x86-based servers. z/OS
applications are mostly single-tier,
while applications on other platforms are multitier. A fundamental
difference exists between singleand multitier application architectures and their placement on
cloud and x86 requires important
considerations.

1

When using DASD in this article, it is
assumed to be ECKD DASD
2
A third choice is to use a Fixed Block
Architecture (FBA) device, but that has
limited applications and won't be
discussed here.
3
Using a FICON Express 16S+ on an
IBM z14®

Single-Tier Applications
So, what's a single-tier application? Most applications have a

programming component and a
data component-meaning programs will use data, which could
be in the form of a simple sequential file, through a complex
database. The programs run and
use data, which must be in-memory with the application. On z/
OS, all resources are shared and
thus many processes run concurrently. This allows for programs
to run and for data to reside, and
be accessed on the same physical
box. If the application component and the data component
run together within the same OS
image, it can be considered to be
single-tier.

John Gustavson is the worldwide CTO of the IBM Eagle Team.
IBMSYSTEMSMAG.COM MAY/JUNE 2020 | 37


http://www.IBMSYSTEMSMAG.COM

IBM Systems magazine, IBM Z - May/June 2020

Table of Contents for the Digital Edition of IBM Systems magazine, IBM Z - May/June 2020

Table of Contents
Editor's Desk: Enabling your success in a hybrid multicloud world
Currents: Arvind Krishna elected IBM CEO, James Whitehurst elected president
Currents: Solutions
Currents: Sustainable battery composition
Currents: The next generation of IBMers on why IBM Z is relevant
Currents: Women in IT value community and mentorship
Currents: A call to all Canadian mainframers
Partner POV: Develop an effective package management strategy to streamline DevOps
Cover Story: Meet the New IBM z15 and IBM LinuxONE III Models: The latest air-cooled systems can help enhance resiliency, security and availability in a hybrid cloud world
The Business Value of the Transformative IBM Z Platform How Feature 1: The Business Value of the Transformative IBM Z Platform: How IBM Z provides tools and capabilities for digital transformation
TECH Showcase: The IBM DS8900F family of flash storage systems provides improved encryption, disaster recovery, uptime and scalability
Techbits: Linux on IBM Z and IBM LinuxONE: When to use SCSI versus DASD storage
Techbits: Application tier considerations for moving to the cloud or x86
Techbits: Ask the expert: How can I reduce risk when performing an IBM Z hardware upgrade?
Beyond the Box: IBMer David Hilliard on his role as a locomotive engineer for the Catskill Mountain Railroad
IBM Systems magazine, IBM Z - May/June 2020 - Intro
IBM Systems magazine, IBM Z - May/June 2020 - Table of Contents
IBM Systems magazine, IBM Z - May/June 2020 - Cover2
IBM Systems magazine, IBM Z - May/June 2020 - 1
IBM Systems magazine, IBM Z - May/June 2020 - 2
IBM Systems magazine, IBM Z - May/June 2020 - 3
IBM Systems magazine, IBM Z - May/June 2020 - 4
IBM Systems magazine, IBM Z - May/June 2020 - 5
IBM Systems magazine, IBM Z - May/June 2020 - Editor's Desk: Enabling your success in a hybrid multicloud world
IBM Systems magazine, IBM Z - May/June 2020 - 7
IBM Systems magazine, IBM Z - May/June 2020 - Currents: Solutions
IBM Systems magazine, IBM Z - May/June 2020 - Currents: The next generation of IBMers on why IBM Z is relevant
IBM Systems magazine, IBM Z - May/June 2020 - Currents: Women in IT value community and mentorship
IBM Systems magazine, IBM Z - May/June 2020 - 11
IBM Systems magazine, IBM Z - May/June 2020 - 12
IBM Systems magazine, IBM Z - May/June 2020 - 13
IBM Systems magazine, IBM Z - May/June 2020 - Currents: A call to all Canadian mainframers
IBM Systems magazine, IBM Z - May/June 2020 - 15
IBM Systems magazine, IBM Z - May/June 2020 - Partner POV: Develop an effective package management strategy to streamline DevOps
IBM Systems magazine, IBM Z - May/June 2020 - 17
IBM Systems magazine, IBM Z - May/June 2020 - Cover Story: Meet the New IBM z15 and IBM LinuxONE III Models: The latest air-cooled systems can help enhance resiliency, security and availability in a hybrid cloud world
IBM Systems magazine, IBM Z - May/June 2020 - 19
IBM Systems magazine, IBM Z - May/June 2020 - 20
IBM Systems magazine, IBM Z - May/June 2020 - 21
IBM Systems magazine, IBM Z - May/June 2020 - 22
IBM Systems magazine, IBM Z - May/June 2020 - 23
IBM Systems magazine, IBM Z - May/June 2020 - The Business Value of the Transformative IBM Z Platform How Feature 1: The Business Value of the Transformative IBM Z Platform: How IBM Z provides tools and capabilities for digital transformation
IBM Systems magazine, IBM Z - May/June 2020 - 25
IBM Systems magazine, IBM Z - May/June 2020 - 26
IBM Systems magazine, IBM Z - May/June 2020 - 27
IBM Systems magazine, IBM Z - May/June 2020 - 28
IBM Systems magazine, IBM Z - May/June 2020 - TECH Showcase: The IBM DS8900F family of flash storage systems provides improved encryption, disaster recovery, uptime and scalability
IBM Systems magazine, IBM Z - May/June 2020 - 30
IBM Systems magazine, IBM Z - May/June 2020 - 31
IBM Systems magazine, IBM Z - May/June 2020 - 32
IBM Systems magazine, IBM Z - May/June 2020 - 33
IBM Systems magazine, IBM Z - May/June 2020 - 34
IBM Systems magazine, IBM Z - May/June 2020 - Techbits: Linux on IBM Z and IBM LinuxONE: When to use SCSI versus DASD storage
IBM Systems magazine, IBM Z - May/June 2020 - 36
IBM Systems magazine, IBM Z - May/June 2020 - Techbits: Application tier considerations for moving to the cloud or x86
IBM Systems magazine, IBM Z - May/June 2020 - 38
IBM Systems magazine, IBM Z - May/June 2020 - Techbits: Ask the expert: How can I reduce risk when performing an IBM Z hardware upgrade?
IBM Systems magazine, IBM Z - May/June 2020 - Beyond the Box: IBMer David Hilliard on his role as a locomotive engineer for the Catskill Mountain Railroad
IBM Systems magazine, IBM Z - May/June 2020 - Cover3
IBM Systems magazine, IBM Z - May/June 2020 - Cover4
IBM Systems magazine, IBM Z - May/June 2020 - SD
IBM Systems magazine, IBM Z - May/June 2020 - CoverSD1
IBM Systems magazine, IBM Z - May/June 2020 - CoverSD2
IBM Systems magazine, IBM Z - May/June 2020 - SD1
IBM Systems magazine, IBM Z - May/June 2020 - SD2
IBM Systems magazine, IBM Z - May/June 2020 - SD3
IBM Systems magazine, IBM Z - May/June 2020 - SD4
IBM Systems magazine, IBM Z - May/June 2020 - CT1
IBM Systems magazine, IBM Z - May/June 2020 - CT2
IBM Systems magazine, IBM Z - May/June 2020 - SD5
IBM Systems magazine, IBM Z - May/June 2020 - SD6
IBM Systems magazine, IBM Z - May/June 2020 - SD7
IBM Systems magazine, IBM Z - May/June 2020 - SD8
IBM Systems magazine, IBM Z - May/June 2020 - SD9
IBM Systems magazine, IBM Z - May/June 2020 - SD10
IBM Systems magazine, IBM Z - May/June 2020 - SD11
IBM Systems magazine, IBM Z - May/June 2020 - SD12
IBM Systems magazine, IBM Z - May/June 2020 - SD13
IBM Systems magazine, IBM Z - May/June 2020 - SD14
IBM Systems magazine, IBM Z - May/June 2020 - SD15
IBM Systems magazine, IBM Z - May/June 2020 - SD16
IBM Systems magazine, IBM Z - May/June 2020 - SD17
IBM Systems magazine, IBM Z - May/June 2020 - SD18
IBM Systems magazine, IBM Z - May/June 2020 - SD19
IBM Systems magazine, IBM Z - May/June 2020 - SD20
IBM Systems magazine, IBM Z - May/June 2020 - SD21
IBM Systems magazine, IBM Z - May/June 2020 - SD22
IBM Systems magazine, IBM Z - May/June 2020 - SD23
IBM Systems magazine, IBM Z - May/June 2020 - SD24
IBM Systems magazine, IBM Z - May/June 2020 - SD25
IBM Systems magazine, IBM Z - May/June 2020 - SD26
IBM Systems magazine, IBM Z - May/June 2020 - SD27
IBM Systems magazine, IBM Z - May/June 2020 - SD28
IBM Systems magazine, IBM Z - May/June 2020 - SD29
IBM Systems magazine, IBM Z - May/June 2020 - SD30
IBM Systems magazine, IBM Z - May/June 2020 - SD31
IBM Systems magazine, IBM Z - May/June 2020 - SD32
IBM Systems magazine, IBM Z - May/June 2020 - SD33
IBM Systems magazine, IBM Z - May/June 2020 - SD34
IBM Systems magazine, IBM Z - May/June 2020 - SD35
IBM Systems magazine, IBM Z - May/June 2020 - SD36
IBM Systems magazine, IBM Z - May/June 2020 - SD39
IBM Systems magazine, IBM Z - May/June 2020 - SD40
IBM Systems magazine, IBM Z - May/June 2020 - SD41
IBM Systems magazine, IBM Z - May/June 2020 - SD42
IBM Systems magazine, IBM Z - May/June 2020 - SD43
IBM Systems magazine, IBM Z - May/June 2020 - SD44
IBM Systems magazine, IBM Z - May/June 2020 - SD45
IBM Systems magazine, IBM Z - May/June 2020 - SD46
IBM Systems magazine, IBM Z - May/June 2020 - SD47
IBM Systems magazine, IBM Z - May/June 2020 - SD48
IBM Systems magazine, IBM Z - May/June 2020 - SD49
IBM Systems magazine, IBM Z - May/June 2020 - SD50
IBM Systems magazine, IBM Z - May/June 2020 - SD51
IBM Systems magazine, IBM Z - May/June 2020 - SD52
IBM Systems magazine, IBM Z - May/June 2020 - SD53
IBM Systems magazine, IBM Z - May/June 2020 - SD54
IBM Systems magazine, IBM Z - May/June 2020 - SD55
IBM Systems magazine, IBM Z - May/June 2020 - SD56
IBM Systems magazine, IBM Z - May/June 2020 - CoverSD3
IBM Systems magazine, IBM Z - May/June 2020 - CoverSD4
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