Currently, We are running single machine base deployment of Enterprise 11.5 with CPU v4 and 20 GB RAM.
We are planning to run hybrid model ( keeping Portal, datastore and web adaptors, SQL Server) on premise and move ArcGIS Server (hosting) to the cloud in AZURE.
Currently, we are running about 50 to 60 map Services, may increase in future ( Some of them are dedicated and other are Shared) and have few GP Services (10 to 12).
Just wanted to know , is this correct deployment process ? Moving Hosting Server to the Cloud?
I'm not going to say it's not possible or that it won't work, but running some components on-premise and some on the cloud could very much potentially cause you to have severe performance issues with your services. I imagine the latency will be very noticeable.
All ArcGIS Enterprise components need to be in the same physical location. Either in the same physical location on-premise, or in the same region/availability zone in the cloud.
Have any link or documentation to dig further ?
I recommend visiting the ArcGIS Well-Architected Framework.
The most important thing for ArcGIS Server is to be close to the data. Since Portal communicates with ArcGIS Server mainly through HTTPS, it can handle some latency, although I would never recommend having only one component of your ArcGIS Enterprise deployment in the cloud and the rest on-prem. Specifically having an ArcGIS Server in the cloud, and its data sources are on-prem will lead to terrible performance, to the point of being unusable.
We are looking options for hybrid . Can we have portal , data store on premise and rest on cloud which includes sql server ?
Why hybrid? Why not move the entire deployment into the cloud?
If we would like to migrate all components with Database, How could we start ? like installing on the cloud, data migration etc.
This technical paper might help provide some insights on the methodology of migrating. https://www.esri.com/content/dam/esrisites/en-us/media/technical-papers/arcgis-enterprise-and-cloud-...
This video might help too: https://mediaspace.esri.com/media/t/1_6iw4ydg1/309413912
There are various approaches you can take, it just depends on the needs of your organization. There's pros and cons to each method, but I recommend viewing the resources I linked above to learn more.