Principles of the reliability pillar
Building a reliable application in the cloud is different from traditional application development. While historically you may have purchased levels of redundant higher-end hardware to minimize the chance of an entire application platform failing, in the cloud, we acknowledge up front that failures will happen. Instead of trying to prevent failures altogether, the goal is to minimize the effects of a single failing component.
Considerations for Migration
The following section provides an overview of Skytap on Azure Architecture and is used as a lens to assess the reliability of an environment deployed in Skytap.
Migration Considerations include:
-
Skytap on Azure General Architecture
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Supported LPARs
Skytap Discovery and Migration – Support and Limits
The following section outlines Skytap on Azure support and limits for IBM i and AIX.
Skytap for Azure Support and Limits (IBM i)
Compute
LPAR Sizing and OS Support for Power
- S922 System p Frames
- IBM i P10 License Class
- 512 GB RAM per LPAR
- CPW up to 60000 per LPAR
- Supports:
- IBM i: 7.2 TR 9, 7.3 TR 5, 7.4
Network
- IPSec (SDN) / PNC Connectivity Between Skytap and On-Premises
- Range: 750 Mbps Limit
- Layer 2 networking in environment
- Range: Burst to 2.7 Gbps Limit
- 10 NICs Per Host
- 10 VPN Connections Per Account
Storage
- Limit of 32 Disks for POWER
- Each Disk Limited to 2TB
- Storage performance scalability with VM/LPAR RAM capacity
- IOPS up to 30K per LPAR
Skytap for Azure Support and Limits (AIX)
Compute
LPAR Sizing and OS Support for Power
- S922 System p Frames
- IBM i P10 License Class
- Up to 16 vCPU / 512 GB RAM per LPAR
- Higher RAM capacity supported on as needed basis (~1.6TB)
- Supports:
- AIX: 6.1 TL 9 SP 10
- AIX: 7.1 TL 4 SP 4,
- AIX: 7.2 TL 1, SP 2
Network
- IPSec (SDN) / PNC Connectivity Between Skytap and On-Premises
- Range: 750 Mbps Limit
- Layer 2 networking in environment
- Range: Burst to 2.7 Gbps Limit
- 10 NICs Per Host
- 10 VPN Connections Per Account
Storage
- Limit of 32 Disks for POWER
- Each Disk Limited to 2TB
- Storage performance scalability with VM/LPAR RAM capacity
- All SSD technology and encrypted
- IOPS up to 30K per LPAR
High-Level Considerations for Migration to Skytap on Azure
Migration to Skytap on Azure can be migrated via a hot or cold/warm migration as depicted here.
Definitions
RTO: Downtime of services, apps and infrastructure for business continuity – i.e., the amount of time it takes to get back up and running in the event of a disaster or outage.
RPO: Frequency of data backup – i.e., the amount of time in which data may be lost.
The two numbers above, combined with contingencies like distance, amount of data rate change and available bandwidth will determine whether to employ a High Availability Tool or a Disaster Recovery Tool.
This is VERY similar to a WARM versus HOT migration, and the same tools may be utilized.
Next steps
Main Overview
Operational Excellence
Resiliency
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Design
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