You’re correct. Attaching a persistent disk currently prevents zero-downtime deploys (Disks for Persistent File Storage | Render). We plan to remove this limitation, but in the meantime I think we can find a workaround.
Am I correct in assuming that the image resizing happens as part of the build process? If so, you may be able to leverage the build cache. Anything you store in
XDG_CACHE_HOME (the cache directory) will persist between builds, unless you deliberately clear the cache with a “Clear build cache & deploy” or the total cache size exceeds 7GB.
You may also want to consider creating a Render static site that rewrites to your Next.js web service (see URL Redirects and Rewrites | Render). This would let you leverage our free global CDN and would prevent downtime, at least for static assets that are cached in the CDN.
I’m happy to elaborate on any of this if you have questions!