Yes, Windows does this. I stumbled onto that too when my incremental backups were ‘randomly’ big. It’s just one of many many thing that are terribly broken about Windows and especially NTFS. The issue is that the scheduled task performs media-specific “optimizations” by default, which in case of SSD does normally only mean retrim, but every so often also an actual defrag. I disabled the task and do it manually now. You still have “live” trims when you deleted files, at least on NVMe, I think it’s off for SATA drives though, as many are buggy with it.
Another really stupid thing is that you should disable shadow copies, otherwise it can happen that data gets written as many times as you have (persistent) shadow copies, eg writing 1G with 6 shadow copies -> 6G written. Absolutely insane.
You often hear this type of “internet wisdom” repeated from decades ago that all this is a solved problem, but it’s really not and no one cares about fixing these fundamental issues at Microsoft. They did seemingly pick up work on ReFS again, but from reports it’s still very buggy and who knows if it will be ready for Windows 12 next year or if that is even their goal.
Yes, Windows does this. I stumbled onto that too when my incremental backups were ‘randomly’ big. It’s just one of many many thing that are terribly broken about Windows and especially NTFS. The issue is that the scheduled task performs media-specific “optimizations” by default, which in case of SSD does normally only mean retrim, but every so often also an actual defrag. I disabled the task and do it manually now. You still have “live” trims when you deleted files, at least on NVMe, I think it’s off for SATA drives though, as many are buggy with it.
Another really stupid thing is that you should disable shadow copies, otherwise it can happen that data gets written as many times as you have (persistent) shadow copies, eg writing 1G with 6 shadow copies -> 6G written. Absolutely insane.
You often hear this type of “internet wisdom” repeated from decades ago that all this is a solved problem, but it’s really not and no one cares about fixing these fundamental issues at Microsoft. They did seemingly pick up work on ReFS again, but from reports it’s still very buggy and who knows if it will be ready for Windows 12 next year or if that is even their goal.