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The Invisible Files on S3: Paying for Data You Can't See (Incomplete Multipart Uploads)

A large upload to S3 dies mid-transfer. The parts that already made it up don’t just vanish — they keep sitting there, billed every month, invisible to the console and to aws s3 ls. Hi everyone 👋 When an application uploads a large file to S3 using multipart upload and the connection drops partway through, the obvious assumption is: the upload failed, nothing happened, no harm done. That assumption is wrong in a way that quietly costs money.

Saturday, August 1, 2026 Read
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Archiving Millions of Small Files to Glacier: When the 'Cheap Storage' Trick Backfires

S3 Glacier Deep Archive is famous for dirt-cheap long-term storage. Point a Lifecycle Rule at millions of tiny log files, though, and “cheap” can flip into “more expensive than doing nothing at all.” Hi everyone 👋 I once confidently set up an S3 Lifecycle Rule: “any object older than 30 days automatically transitions to Glacier Deep Archive.” Simple, standard cost-optimization advice. The catch: the bucket in question held millions of small log files, each only a few KB.

Friday, July 10, 2026 Read