Hello, as proxmox hypervisor does not offer mdadm software raid at installation time because of this bugticket "MD RAID or DRBD can be broken from userspace when using O_DIRECT" https://bugzilla.kernel.org/show_bug.cgi?id=99171 i tried to find some more references besides the kernel bugzilla entry - and - besides some discussion in the proxmox community - i did not succeed. why is this apparent fundamental design flaw (should we call it that?) so damn unknown ? and what about O_DIRECT with other software raid solutions like btrfs or zfs ? how/why do they right but not mdraid ? the latter exists for much longer time and afaik is offered as install-time option for RHEL (enterprise linux) for example, where people use oracle on top - which IS using O_DIRECT very often/likely. not accusing anyone - just being curious why totally unknown/unpopular bugticket #99171 bitrots for nearly a decade now... regards Roland Sysadmin ps: also see "qemu cache=none should not be used with mdadm" https://bugzilla.proxmox.com/show_bug.cgi?id=5235
