Hot-tier storage accounts averaging under 0.05 transactions a day
What does ZopNight detect here?
Hot tier buys cheap transactions with an expensive per-GB rate, which is backwards for cold data. ZopNight flags accounts whose measured blob transaction rate averages below 0.05 per day over 30 days, pricing the Cool switch as the real hot-to-cool rate difference multiplied by the account's stored gigabytes.
Signal and threshold
| Field | Value |
|---|---|
| Rule IDs | RC-1325 |
| Category | rightsizing |
| Severity | medium |
| Metric | none — pure configuration read |
| Source | storage_tier.go |
Where it applies
Hot pricing is a bet on activity
Azure’s Hot access tier trades a premium per-GB storage rate for the cheapest transactions; Cool inverts the trade. An account holding archives, old exports, or a finished project’s artifacts on Hot is paying the activity premium on data nobody touches. The mispricing is per-GB and compounds monthly, which makes large cold accounts some of the most durable savings in a storage estate.
Measured coldness, at a strict threshold
The rule requires the account’s tier metadata to read hot, then consults a measured transaction-rate series derived from the blob service’s own metrics. Only an average below 0.05 transactions per day, effectively one or two touches a month, counts as cold. The gate fails closed: with no metric present, an account is never assumed cold, because a wrong retier moves active data onto per-GB read penalties.
The savings math shown in full
The dollar figure is the hot-to-cool per-GB rate difference multiplied by the account’s stored capacity, computed from your region’s actual rates over a 730-hour month, never a percentage guess. When ZopNight’s separate storage-account traffic rule fires a Hot-to-Cool retier on the same account, the two are consolidated into one recommendation so the identical delta is never counted twice. Missing capacity or rate data means the finding is withheld.
Confirm tier and traffic together
az storage account show -n <account> -g <rg> --query accessTier -o tsvaz monitor metrics list \ --resource "$(az storage account show -n <account> -g <rg> --query id -o tsv)/blobServices/default" \ --metric Transactions --interval P1D --offset 30d --aggregation TotalSwitching tiers without surprises
The account-level flip to Cool is one setting under Configuration, applies to base blobs without rehydration delay, and is reversible. Two caveats deserve a check first: Cool reads carry a small per-GB access charge, so verify the account stays cold; and blobs deleted or retiered within 30 days of landing in Cool incur an early-deletion charge.
Inputs behind the finding
Reader supplies the tier metadata, Monitoring Reader the transaction series, and Cost Management Reader the billed baseline the delta is clamped against. The saving is always capped at the account’s actual monthly cost.