Post by @fedops@fosstodon.org

2026-04-13 18:37 UTC

@quad@akko.quad.moe I started with 4 disks in raidz1 as I'll likely catch a failing disk early on. With raidz expansion I can always add more when the time comes. I'm more interested in capacity than performance though with a measly gigabit the CPU barely budges (on a Ryzen 7, not the Terramaster).

Replies (1)

@quad@akko.quad.moe 2026-04-13 18:48

@fedops@fosstodon.org Well I currently have the same setup. Four drives in a Z1. My main problem is mostly async IO clogs. if we pretend that hard links don't exist a moment for the sake of demonstration. Copying a 100GB folder containing a few seasons of anime to another location, the copy technically reports as "finished" pretty quickly and the command exits. But the next time zfs flushes async (is it every 5 seconds by default?) my HDDs will go into overdrive and be 100% active, causing iowait to go from like 10ms to 150ms for everything else on the system and my load average will exceed my number of CPU cores. The system then basically chugs like that for ages while ZFS figures out the actual work behind the scenes and everything else trying to access the pool suffers. With mdraid+ or bcachefs the copy command itself would actually work until the copy had really happened, but while the copy was happening the impact on the rest of the system would be a lot lower.

Open ##1132308