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fix: default DISK_IO to native so QEMU boots on kernels before 5.12 - #7
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dockur 6.06 lets QEMU 11 pick io_uring, which on older kernels (Ubuntu 20.04's 5.4 among them) fails at boot with "Failed to initialize io_uring: Cannot allocate memory" because the buffers count against the container's 64 KB memlock limit. native works everywhere; io_uring stays available through DISK_IO in .env. README: storage/ and shared/ are written by the container as root, so the "start over" instructions now use sudo.
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Current Behaviour
On a host with a kernel older than 5.12 (Ubuntu 20.04 ships 5.4) the first start ends right after "Booting Windows using QEMU":
and the container restarts in a loop. dockur 6.06 lets QEMU 11 choose io_uring for disk I/O, whose buffers are charged against the container's locked-memory limit on those kernels, and Docker caps that at 64 KB.
Also,
storage/andshared/are written by the container as root, so the README's "delete storage/" instructions fail for a normal user.Expected Behaviour
docker-compose.ymlsetsDISK_IOtonative, the Linux AIO backend that works on every kernel. It can be overridden from.env;io_uringremains available on kernels 5.12 and newer..env.exampleand the README table document the three values and whenio_uringis safe.sudo rm -rf storage shared.docker compose configpasses. The setting maps to QEMU'saio=native, confirmed in dockur's disk.sh. Not yet confirmed on the affected host at the time of merging; the host is being re-run with this setting.