Try mounting / once

[ezrizhu]

via merger/unionfs

[ezrizhu]

we have good progress on this with root.

root@pashsn3:~# unshare --mount --user --pid --fork /bin/sh
((do gidmapping here # gidmapper 67195 0 0 65535 0 0 65535))
$ pwd
/root
$ mkdir overlay
$ cd overlay
$ mkdir low up merged work
$ mergerfs / low
$ mount -t overlay overlay -o userxattr -o lowerdir=low,upperdir=up,workdir=work merged
$ chroot merged /bin/bash
root@pashsn3:/# touch x
root@pashsn3:/# echo z > x
root@pashsn3:/#

Can not reproduce this with out running as root. Getting EOVERFLOW

[ezrizhu]

Progress also made by @SleepyMug on 0621375