[systemd-devel] [PATCH] fstab-generator: Support root on tmpfs

Tobias Hunger tobias.hunger at gmail.com
Mon Mar 23 03:39:30 PDT 2015

Hi Vasiliy,

from what I read lowerdir, upperdir and workdir need to be
directories, not devices. So how can you mount those three directories
before setting up an overlayfs using them?

That should be possible with a couple of units injected into the
initrd, but to me this seems more than what the fstab-generator can
support at this time.

Best Regards,

On Mon, Mar 23, 2015 at 11:17 AM, Vasiliy Tolstov <v.tolstov at selfip.ru> wrote:
> 2015-03-23 13:02 GMT+03:00 Tobias Hunger <tobias.hunger at gmail.com>:
>> I never used overlayfs myself, can you set up an overlayfs via the
>> kernel commandline arguments supported by the fstab-generator? Those
>> are device, options and fstype for the root and usr.
>> If a overlayfs setup can not be shoehorned into the (two times) three
>> flags we have support for in fstab-generator at this time, then I'd
>> say it is out of scope for this patch.
> overlay fs simply mounts like mount -t overlay overlay
> -olowerdir=/lower,upperdir=/upper,workdir=/work /merged
> so in term of cmdline we have
> fstype - overlay
> device - none or overlay
> options - lowerdir,upperdir,work
> desitnation - /
> --
> Vasiliy Tolstov,
> e-mail: v.tolstov at selfip.ru
> jabber: vase at selfip.ru

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