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

Sat, 01 Aug 2026 14:00:00 +0700

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.

Archiving Millions of Small Files to Glacier: When the 'Cheap Storage' Trick Backfires

Fri, 10 Jul 2026 09:00:00 +0700

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.

S3 on The David Page

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

Archiving Millions of Small Files to Glacier: When the 'Cheap Storage' Trick Backfires