Hey Wol, thanks for your email. > I just thought. Is your scrub a "check" or "repair"? It's a check "using" Debian's/Ubuntu's standard /usr/share/mdadm/checkarray cronjob. But as mentioned in the other subthread, check should also fix the errors (and does seem to attempt to, given that the last out of 4 scrubs failed with a write error). > The other thing is, mdadm 3.3 ... I'd upgrade that if I were you. It's got known bugs including problems with mirrors ... I don't think there's any problems with scrubs, though, so it's a "general principles" advice to upgrade, not a "you need to". Like (probably) most people, I'm upgrading with the upgrade cycles of my Linux distribution. That's Ubuntu 16.04 LTS in this case, which is supported and supposed backport important bugfixes until 2021 (I am scheduled to upgrade to 18.04 LTS during the next holidays, ideally after this RAID situation is sorted out). >From a short look at the current changelog, it seems like they do indeed perform the promised backporting: http://changelogs.ubuntu.com/changelogs/pool/main/m/mdadm/mdadm_3.3-2ubuntu7.6/changelog Though I cannot easily judge whether this includes all fixes they should be cherry-picking.
