while testing grub2 2.02-beta2 it appeared the grub is inserting backslash escapes for symbols '\\', '\\'' and '"' while processing multiboot command line. Unfortunately current libzfs only allows simple disk illumos kernel does not process such escapes and mirror setup therefore the bootpath and diskdevid properties (set by -B $ZFS_BOOTFS mechanism) processing is broken if such escapes appear. The problem is that current code, while looking for boot pool, property value, is expecting quote (" or ') to appear as loader does support booting from raidz, this feature first symbol of value string, but instead it will remove raidz restriction from boot pool setup. find the '\\', and therefore whole quote check logic will be broken and property values are split at commas and quoting is not recognised. the result is broken values for bootfs and diskdevid, therefore rootfs can't be mounted and kernel will panic, as there is no rootfs.