New blocks remain in an uncommitted state until they are specifically committed or discarded.
Writing a block does not update the last modified time of an existing blob.
Each block can include an MD5 hash to verify the transfer, so you can track upload progress and re-send blocks as needed.
You can upload blocks in any order, and determine their sequence in the final block list commitment step.
Each block can be a different size, up to a maximum of 100 MB (4 MB for requests using REST versions before 2016-05-31), and a block blob can include up to 50,000 blocks.
The maximum size of a block blob is therefore slightly more than 4.75 TB (100 MB X 50,000 blocks).
Writes to page blobs happen in-place and are immediately committed to the blob. With the introduction of new Premium Storage, Microsoft Azure now offers two types of durable storage: Premium Storage and Standard Storage.Storage clients default to a 32 MB maximum single block upload, settable using the Single Blob Upload Threshold In Bytes property.When a block blob upload is larger than the value in this property, storage clients break the file into blocks.You can also upload a new block to replace an existing uncommitted block of the same block ID.You have one week to commit blocks to a blob before they are discarded.