An unexpected storage error occurred

I just found out this…

cache at :storage/caches/df9fb128-c5f3-483e-bfc1-0520d982dfd9/windows-cache-arch1-windows-amd64-1_-14-73c6HErVXAzvJgetlV9pKGSsRHk8M10STYgLokkZAhs=.tar.gz failed:
an unexpected storage error occurred (operation id: 236f3952)

…has been occurring for months with our Windows builds. We have very similar Linux builds that have been consistently working.

Searching I found this…

It was not helpful.

85,404,139,520 bytes free

The cache file has been running about 3 GiB so there’s plenty of storage available.

Searching for “an unexpected storage error occurred” reveals the message to be unique to CircleCI and provided no help.

Does caching work under Windows? Suggestions?


We recommend keeping cache sizes under 500MB. This is our upper limit for corruption checks. Above this limit, check times would be excessively long. More information can be found on the link below

Is it possible to split your cache into smaller chunks if possible so that each cache is under 500MB?

Kind Regards
Owen Oliver

The total size of the uncompressed cached data on the Linux machine is just over 6 GiB. The restore cache step reports the size as 1.9 GiB. I assume that’s the size of the archive file. That works.

The total size of the uncompressed cached data on the Windows machine is just over 1.2 GiB. That fails. Consistently.

Is that 500 MiB limit specific to Windows?