I have about 1.5 PB of data in the Archive tier of an Azure Storage account. The data is no longer needed, and I want to delete it all while also removing the lifecycle rule that moves blobs into Archive. I initially assumed that removing the Archive tier would rehydrate the data and move it into Cold storage, after which I could delete it.
If rehydration were necessary, I estimated that keeping 1,500 TB in Cold storage for one week at roughly $4 per TB per month would cost about $1,400, based on a 30-day month. Is that a reasonable way to estimate the charge, or does Azure calculate this differently? Are there additional retrieval or rehydration costs?
Also, is there a simpler way to delete blobs directly from Archive without rehydrating them first?
3 Answers
Your Cold storage estimate is roughly correct as a storage-only calculation: 1,500 TB × $4 per TB per month is about $6,000 per month, or around $1,400 for seven days using a 30-day month. However, rehydrating first would add retrieval charges, which could be much more expensive. At an approximate $0.02 per GB, 1.5 PB could mean roughly $30,000 in retrieval charges before considering storage.
You can delete blobs directly while they’re still in the Archive tier. There’s no need to change the tier or rehydrate the data first. Delete operations can be performed through the portal, CLI, or SDK, and you should also disable or remove the lifecycle rule so new data doesn’t get archived.
Check the Archive early-deletion minimum. Blobs generally have a 180-day minimum retention period in Archive, so deleting data before that period expires can result in a prorated charge for the remaining days. Data that has already satisfied the minimum period should not incur that additional early-deletion cost.
It’s effectively a charge for the remaining minimum-retention period rather than a separate deletion fee. If the blobs have already been in Archive for the full minimum period, deleting them directly is usually the least expensive option.
That’s what I found after testing it. The data was still accessible for deletion even though I initially thought rehydration would be required.