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On Fri, May 16, 2014 at 7:10 AM, Stefan G. Weichinger <lists@×××××.at> wrote: |
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> Am 16.05.2014 13:56, schrieb Bruce Schultz: |
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> |
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>>> I ask because in all my reorganizing furor I also thought that now |
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>>> with btrfs only I could get rid of "lvm mdraid" as dracut-modules. |
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>>> I can try ... ;-) (don't call me "ricer") |
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>> |
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>> If you have a multi-disk btrfs, I think you need to add the btrfs |
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>> dracut module. At least that's how I remember it, but its been a |
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>> while & my memory could be failing me, or it could well have changed |
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>> since then. |
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> |
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> I currently have in /etc/dracut.conf: |
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> |
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> add_dracutmodules+="bash systemd" |
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> hostonly="yes" |
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> hostonly_cmdline="yes" |
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> |
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> and am able to boot via grub2 and efi, that means, |
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> |
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> /boot/efi (vfat) on /dev/sda1 (sda is the SSD) |
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> |
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> and |
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> |
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> / as btrfs-subvol on /dev/sda2 (with /boot as directory on it). |
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> |
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> So no multi-disk btrfs for / or /boot on this machine. |
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> |
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> - |
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> |
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> removing "lvm mdraid" from dracut slimmed down the initrd from around |
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> 6.8 MB to 5.5 MB ... nice, but not necessary as Canek mentioned. |
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> |
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> I just "play" with it to learn and understand even better. |
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> |
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> I am not sure what the module "systemd" does or is good for, and |
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> |
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> https://www.kernel.org/pub/linux/utils/boot/dracut/dracut.html#dracut.kernel |
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> |
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> does look scary and didn't tell me more about that module yet. |
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|
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With the systemd module, dracut uses systemd as init. So you have your |
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initramfs, which executes systemd to setup the machine up until /usr |
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is mounted, and then that instance of systemd calls the instance of |
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systemd in the hard drive. |
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|
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If you don't use the systemd module, your initramfs uses a custom init |
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script to mount /usr and similar stuff. It seems to work, but I trust |
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more systemd to do it, and I certainly prefer not to rely on any |
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script during boot up. |
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|
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Also, for non-trivial setups, I'm sure systemd handles them better |
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that a custom init script; that's why I recommended John to use the |
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systemd module. |
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|
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Regards. |
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-- |
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Canek Peláez Valdés |
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Profesor de asignatura, Facultad de Ciencias |
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Universidad Nacional Autónoma de México |
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