Re: Installation guide updated

[Roland McGrath <roland@gnu.org>]

> "You may make a swap partition too if you wish, or use your Linux one
>  (in which case you need to modify your boot scripts, but I have no idea
>  which ones to change)."
> 
> It was my understanding that Roland changed that: Hurd will now honour the
> linux swap file structure and not destroy it. But I am not sure if this
> change is in latest Debian package. Just keep an eye open for later.

That is correct.  But I have just checked in some fixes today, so no
existing snapshot has the code, and it is not at all tested (so you will be
the ones to test it!).  We will make a new snapshot soon, or you can always
use anonymous cvs (which should be up to date by tomorrow).


The new situation is as follows:

In the boot script (/boot/servers.boot), you can do (as before):

/dev/hd0s2 $(add-paging-file) $(default-pager)

It will detect a Linux signature page (2.0 or 2.2 variety) and obey what it
says.  If it sees a Linux signature page, it will print something on the
console about it.  If not, it will just use the whole partition (as before).

You can now also do two new variants:

/dev/hd0s1a $(add-raw-paging-file) $(default-pager)

This will use the whole partition regardless, not check for a Linux
signature page at all, and always clobber one if it was there.

And:

/dev/hd0s2 $(add-linux-paging-file) $(default-pager)

This will check for a Linux signature page, and obey it.  If there is no
Linux signature page, it will refuse to use the partition at all.  It will
print something on the console about it either way.  This variant is most
like what Linux does, so Linux users may prefer it.

Note that in all cases the device name can be any of: a whole device
(/dev/hd1, /dev/sd0), a whole partition (/dev/hd0s2, /dev/sd0s1a), or a
file within a disk or partition (/dev/hd1/paging_file,
/dev/sd0s3g/foobar/paging_file).  In the latter case, it can read the same
filesystem formats (ext2fs, ffs, minixfs(?)) that it can read for loading
the programs in the boot script.  Naturally, any modification of any kind
you make to that file using the normal filesystem while you're running will
ruin your life.

When adding swap partitions after boot using /sbin/swapon, it will always
"autodetect" as in $(add-paging-file), obeying a Linux signature page if
it's there but clobbering the whole partition if no signature is found.