mirror_zfs/dracut/README.dracut.markdown

How to setup a zfs root filesystem using dracut
-----------------------------------------------

1) Install the zfs-dracut package.  This package adds a zfs dracut module
to the /usr/share/dracut/modules.d/ directory which allows dracut to
create an initramfs which is zfs aware.

2) Set the bootfs property for the bootable dataset in the pool.  Then set
the dataset mountpoint property to '/'.

    $ zpool set bootfs=pool/dataset
    $ zfs set mountpoint=/ pool/dataset

Alternately, legacy mountpoints can be used by setting the 'root=' option
on the kernel line of your grub.conf/menu.lst configuration file.  Then
set the dataset mountpoint property to 'legacy'.

    $ grub.conf/menu.lst: kernel ... root=ZFS=pool/dataset
    $ zfs set mountpoint=legacy pool/dataset

3) To set zfs module options put them in /etc/modprobe.d/zfs.conf file.
The complete list of zfs module options is available by running the
_modinfo zfs_ command.  Commonly set options include: zfs_arc_min,
zfs_arc_max, zfs_prefetch_disable, and zfs_vdev_max_pending.

4) Finally, create your new initramfs by running dracut.

    $ dracut --force /path/to/initramfs kernel_version
Add dracut support To simplify the process of using zfs as your root filesystem a zfs-drucat sub-package has been added. This sub-package adds a zfs dracut module which allows your initramfs to be rebuilt with zfs support. The process for doing this is still complicated but there is clearly interest from the community about getting this working well and documented. This should help lay some of the groundwork. Longer term these changes should be pushed in the upstream dracut package. Once that occurs this subpackage will no longer be required for new systems, however we may want to conditionally build this package in the future for systems running older dracut versions. Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov> 2011-03-18 01:18:13 +03:00			`How to setup a zfs root filesystem using dracut`
			`-----------------------------------------------`

			`1) Install the zfs-dracut package. This package adds a zfs dracut module`
			`to the /usr/share/dracut/modules.d/ directory which allows dracut to`
			`create an initramfs which is zfs aware.`

			`2) Set the bootfs property for the bootable dataset in the pool. Then set`
			`the dataset mountpoint property to '/'.`

			`$ zpool set bootfs=pool/dataset`
			`$ zfs set mountpoint=/ pool/dataset`

			`Alternately, legacy mountpoints can be used by setting the 'root=' option`
			`on the kernel line of your grub.conf/menu.lst configuration file. Then`
			`set the dataset mountpoint property to 'legacy'.`

			`$ grub.conf/menu.lst: kernel ... root=ZFS=pool/dataset`
			`$ zfs set mountpoint=legacy pool/dataset`

			`3) To set zfs module options put them in /etc/modprobe.d/zfs.conf file.`
			`The complete list of zfs module options is available by running the`
			`_modinfo zfs_ command. Commonly set options include: zfs_arc_min,`
			`zfs_arc_max, zfs_prefetch_disable, and zfs_vdev_max_pending.`

			`4) Finally, create your new initramfs by running dracut.`

			`$ dracut --force /path/to/initramfs kernel_version`