Google told me to use apt-mirror. My updates repository turned out to have some metadata filename with an @ in it, apt-mirror refuses to do anything with this state of affairs. I learned (after poking apt-mirror's page( that this bug was two years old, but the project is not maintained any more. Digging through aptly-mirror's bug tracker I caught a reference to aptly.
I got aptly to work, after applying a reasonable amount of elbow grease. The only unsolvable problem was that after taking a few seconds to download a handful of updates it takes aptly well over an hour to republish the local repository snapshot, to incorporate those updates. The full repository adds up to about 18000 packages, and looks like aptly recompresses each one of them, every time. I don't know why but that's what it does. I see it launching xz over and over again, while aptly keeps me in the loop of how many of those 18000 packages are left to process.
Although I don't need to worry about wearing any SSDs (since it's spinning rust), this is still somewhat suboptimal. So, that brings me to: what do folks use to mirror repositories?
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