Trending cDOT Transition Considerations: What You Need to Know

Trending cDOT Transition Considerations

When considering a transition from current 7-Mode systems to Clustered Data ONTAP (cDOT), it’s important to understand the limitations, timing and complexity. At IDS, we help our customers navigate and understand how this process impacts their production environment. We understand every customer’s architecture is different, but we have compiled some questions that continue to trend in our conversations.

Trending cDOT Transition Questions

How can we deliver benefits of cDOT without impeding the production 7-Mode systems?
We see most customers timing the cDOT transition around a tech refresh. This eliminates the need for swing gear and redundant migrations. The added costs associated with temporary setup and take-down of equipment inside the data center are risks that are being avoided.

How will this impact my applications?
Applications remain unaffected. cDOT is still a unified storage platform serving data via NAS and Block.

How do we provide disaster recovery while performing migration?
Running parallel environments is the only way to guarantee meeting DR SLAs. Remember that cDOT and 7-MODE systems are incompatible.

How many outage windows are needed for cutover?
This depends. Many applications can be migrated with no downtime at all when hosted on virtualized platforms. Since Raw Device Maps cannot be migrated without an outage, further investigation and strategy planning will be need on this topic.

Application migration methods ( i.e. SQL Always on or Exchange DAG) are other methods of achieving a no downtime migration.

Can I simply SnapMirror from 7-Mode to cDOT?
Kind of… There is a migration method called a TDP SnapMirror that can mirror data 7-Mode to cDOT. This only works for NAS data and is disruptive upon cutover.

What’s the same and what’s different?
Many of the features are the same, especially after the 8.3 ONTAP release. The enhancements in scale-out, non-disruptive operation and administration (CLI) are quite different but offer better agility and performance to the enterprise in cDOT.

The latest version of cDOT 8.3 provides many enhancements that will allow seamless integration of the following ONTAP subsystems that were previously only supported in 7-Mode until this release.

• Multistore
• MetroCluster

All other subsystems including the following have either the same or enhanced functionality.

• SnapVault (enhanced)
• SnapMirror (enhanced)
• SnapManager for SQL
• iSCSI Chap
• Networking (ifgrps and LIFs) (enhanced)
• CIFS (enhanced)
• VMware integration
• Snap Creator