We are building a backup solution for our storage accounts in Azure. We sync our data to a secondary storage account. To reduce cost, we are thinking about placing our destination storage account in the 'Cool' access tier since recovery operations are almost never needed. We are using the recent "sync" option of AzCopy to execute the sync between our storage accounts. I was wondering if the "sync" operation was actually accessing all the blobs in the destination storage account (killing the purpose of the cool access tier) or if the operation was only retrieving the metadata/properties of the blob, hence not incurring access fees.
Thanks!
From azcopy sync documentation:
The last modified times are used for comparison. The file is skipped if the last modified time in the destination is more recent.
Considering last modified time property is fetched when you list the blobs (or perform head request on the blob to get blob's properties), you're not really accessing the blob (i.e. reading it).