COW and volume management?
COW and volume management?
Posted Feb 5, 2026 12:38 UTC (Thu) by anton (subscriber, #25547)In reply to: COW and volume management? by marcH
Parent article: Filesystem medley: EROFS, NTFS, and XFS
How do you know it was hype?The kind of fearmongering used for selling ZFS was really off-putting. One supposedly-relevant scenario that ZFS defends against is when a HDD writes a block to the wrong disk sectors. This scenario has never happened in my experience, and the way HDDs work, it cannot happen in the way that the scenario suggests (by the read-write-head arm moving to the wrong track without any additional hardware failure).
That being said, we have used ZFS on many machines since about 2019 (mainly because it was not clear at the time whether RAID1 works well on btrfs), it works nicely. The only downside I see in it is that it is its own universe that ignores things like /etc/fstab and you need to learn the ZFS terminology even for terms that have a correspondence outside the ZFS universe. Another downside I read about is that ZFS supposedly does not utilize RAM as well as native Linux file systems which make better use of the buffer cache or somesuch. We certainly see little free RAM on our machines with ZFS. That's why I have decided to go for btrfs again for one machine recently.