Messages in this thread | | | Date | Tue, 3 May 2022 14:33:39 +0200 | From | Lennart Poettering <> | Subject | Re: [PATCH 2/2] random: add fork_event sysctl for polling VM forks |
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On Di, 03.05.22 13:55, Jason A. Donenfeld (Jason@zx2c4.com) wrote:
> I'm still not convinced there's value in having a counter or a UUID, but > if you had to choose, would you prefer a counter or a UUID? It sounds > like the former, because you see a use for distinguishing between zero > and non-zero? Or did you finally agree with me that vmgenid isn't > granular enough for that?
I would prefer a monotonic counter, since it allows answering questions like the following:
1. Did this image get cloned at all? (i.e. counter != 0; usecase as per the MAC address discussion)
2. Did the image get cloned since the last time I looked? (i.e. counter != my_previously_saved_counter; usecase: detect clones in an "offline" fashion, i.e. from a component that doesn't continously run, but only from time to time)
3. How many clones did I miss? (i.e. missed_clones = my_previously_saved_counter - counter; usecase: catch up with generating proxy D-Bus signal messages for clones).
There might be more.
Using a UUID would not give us #1 or #3. It would deliver #2 however.
Lennart
-- Lennart Poettering, Berlin
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