Fault Domains – refers to rack of servers with subsystems like network, power, cooling etc. VMs in the same availability set means Azure will provision them in 2 different racks. The maximum value of fault domain is 2.
Update Domain – refers a logical unit of a deployment. Whenever any update needs to be applied at the host level, the VMs in same update domain would be restarted in the order to avoid impact to services and applications.
Storage Replication options – 4LZGRaG
- Locally Redundant (Standard_LRS) – 3 data copies in single facility in a single location
- Zone Redundant (Standard_ZRS) – 3 data copies in two or three facilities in a single location (BLOB only)
- Geo-Redundant (Standard_GRS) – LRS + 3 data copies stored in a secondary location (most resilient)
- Read-Access Geo-Redundant (Standard_RAGRS) – Same as GRS but at a failover state the data in secondary location is Read Only
Types of Storage – 4BTQF
- BLOB Storage – Binary Large Objects; any type of file or binary data; Storage for storing unstructured data. E.g., Documents, images, videos, logs files, VM Disks (vhd)
- Table Storage – Tables to store data; these tables have no schema, developers can use table storage to develop based on fast changing requirements.
- Queue Storage – Distributed applications need to communicate asynchronously. Queueing is one mechanism for such communication.
- File Storage – It is like a file share; SMB share. Can be mapped using a network drive
Types of blob Storage 3BAP
- Block blobs are optimized for streaming and storing cloud objects, and are a good choice for storing documents, media files, backups etc.
- Append blobs are similar to block blobs, but are optimized for append operations. An append blob can be updated only by adding a new block to the end. Append blobs are a good choice for scenarios such as logging, where new data needs to be written only to the end of the blob.
- Page blobs are optimized for representing IaaS disks and supporting random writes, and may be up to 1 TB in size. An Azure virtual machine network attached IaaS disk is a VHD stored as a page blob.
This blog list the basic questions and answers we come across as System Admins on Microsoft Technologies.
The posts are divided into levels as L1, L2 and L3.