Comment by hedora
If it’s at 5-15ms of downtime already, you’re in the space where the “zero” downtime FS might actually cause more downtime. In addition to pauses while the snapshot is taken, you’d need to carefully measure things like performance degradation while the snapshot exists (incurring COW costs) and while it’s being GCed in the background.
Also, the last time I checked the Linux scheduling quanta was about 10ms, so it’s not clear backups are going to even be the maximum duration downtime while the system is healthy.
I am not so sure you know what you are talking about. Feel free to provide some reading material for my education.
Why would the scheduler tick frequency even matters for this discussion. Even on a single cpu/core/thread system. For what is worth, the default scheduler tick rate has been 2.5ms since 2005. Earlier this year somebody proposed switching back to 1ms.
https://btrfs.readthedocs.io/en/latest/dev/dev-btrfs-design.... https://docs.kernel.org/admin-guide/pm/cpuidle.html https://docs.redhat.com/en/documentation/red_hat_enterprise_... https://sqlite.org/wal.html#ckpt https://www.phoronix.com/news/Linux-2025-Proposal-1000Hz