Can copy-on-write fail in production?
Yes. If the box has tight RAM (e.g., 10 GB heap on a 12 GB instance) and writes are frequent, the memory spike during BGSAVE can trigger OOM even though the post-dump size is normal.
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Copy-on-Write Snapshotsfork() shares parent memory, copying only written pages for non-blocking snapshots. Write-heavy loads can spike memory to 2x under load.
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