Re: Attempt to Move Root
On Tue, 22 Dec 2015 10:57:41 -0500 (EST), Nicolas George wrote:
>
> What you write is slightly inaccurate. The core of your inaccuracy is this:
> LILO does not use the BIOS to read FILES, but SECTORS. How to map files to
> sectors is entirely LILO's problem.
That depends on your point of view. To lilo's map installer (the lilo command
that runs at a Linux shell prompt) they are files. The LILO boot loader
itself reads an ordered list of sectors created for it by the map installer.
But it is still a file. If what you mean is that the LILO boot loader,
at boot time, cannot determine which sectors to read based on examining
the file system structures, then yes, that is true.
>
> IIRC, the mapping is computed when (re)installing LILO on the boot-sector
> and hard-coded in the boot-sector itself, with one level of indirection (the
> map file). After a quick glance at the sources, it uses the FIBMAP ioctl and
> various others to ask the kernel the blocks used by a file and converts to
> sectors. At the same time, I noticed that LILO seems to be actually capable
> of finding the sectors for files on LVM.
In the general case, the sectors of a file on an LVM2 logical volume may
reside on multiple physical partitions on multiple physical disks. But if
all of those disks are addressable via the BIOS, and all of the sectors
are accessible via the BIOS, then it may be theoretically possible for LILO
to read the map file, the kernel image file, and the initial RAM file system
image file from an LVM2 logical volume at boot time. I guess I was making
an implicit assumption that they would all have to be on the same physical
device. But maybe that's not true. I'll have to look into that.
>
> I have not read this thread carefully, so maybe it has already been
> addressed, but all this suggest that the OP should install GRUB instead of
> LILO and be done with that kind of trouble.
As subsequent posts have indicated, the trouble was with an incorrect UUID.
It had nothing to do with the OP's choice of boot loader.
--
.''`. Stephen Powell <zlinuxman@wowway.com>
: :' :
`. `'`
`-
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