ai and ml

Clumsy logging implementation squirrels away data without regard for cost

Modern SSDs have a limited number of write cycles before they expire. Now, OpenAI is scrambling to fix a flawed logging implementation that has been shortening the lives of Codex users' solid state drives (SSDs) with excessive data writes and lowering the devices' value by a significant amount of money.

A bug report opened last week for the company's Codex coding agent warns of the consequences in its title: "Codex SQLite feedback logs can write ~640 TB/year and rapidly consume SSD endurance #28224."

"On my machine, after about 21 days of uptime, the main SSD has written about 37 TB," wrote developer Rui Fan, a project management committee member of Apache Flink. "Process/file-level checks show Codex SQLite logs are the main continuous writer.

"That extrapolates to roughly 640 TB/year. On a 1 TB SSD, that is about 640 full-drive writes per year. Some consumer SSDs are rated around 600 TBW, so this could consume roughly a full drive's warranted write endurance in less than a year."

SSDs have a limited lifespan, often measured in terabytes written (TBW). This number varies by model and capacity. Samsung's 2025 9100 PRO SSDs, for example, promise 600 TBW for the 1 TB SSD. And after that point, we expect their performance to degrade and failure becomes more likely.

The problem with Codex is that it has been writing so much logging data to SSD storage that users have become concerned they're shortening the life of their hardware.

Another developer posting in Rui Fan's thread remarked, "Codex analyzed the disk usage and says this bug cost me $38.64 in drive value of my Samsung 990 2 TB NVMe."

This dev subsequently cited the Codex-generated estimate of the overall cost of this bug: "This regression plausibly burned low-single-digit millions of dollars of SSD endurance across users during the March-June Window." 

Codex's economic impact assessment assumes a cost of $0.13 per TB written to SSDs.

This is based on this formula: TB written × (SSD price / SSD TBW). So given a 1 TB SSD, we estimate that Rui Fan incurred a cost of $12.33 for 37 TB of squandered storage. (Cost per TBW = SSD price / SSD endurance = $200 / 600 TBW = $0.333 per TB written.) A more spacious and more costly SSD with a higher TBW rating would cost less per wasted byte (e.g. $0.25 per TB for a $300 / 1200 TBW 2 TB Samsung 9100 PRO SSD). 

In December 2025, Codex devs announced plans to add telemetry by default (except where disallowed by law) to the Codex CLI.

But this issue has to do with local diagnostic logging, which was introduced around the time the app debuted last year and is also on by default. The logs stay on the device unless included by the user in a feedback report.

Concerns about excessive write operations using OpenAI's Codex have been surfacing in the project's GitHub repo for several months.

A spokesperson for OpenAI confirmed that company engineers are aware of the problem and are working to fix it – something evident from several recent pull requests intended to address the problem. We're told that these logs are intended to help OpenAI engineers diagnose issues and that the problem was the result of high-volume data that was being stored in a way that created far more disk activity than anticipated.

While purported fixes have been landing and the company has made some progress, users continue to file problems.

The issue appears to date back to work done in February to write app-server SQLite logs at TRACE level, which emits more verbose logs than, say, ERROR level. 

We note that Codex, presumably running GPT-5.3, reviewed this particular series of commits. That makes it all the more surprising that the code was so ill-conceived. ®