livecd-iso-to-disk.sh and extension size

[D. Hugh Redelmeier]

I've often had problems with putting Linux on USB sticks.  Fedora, 
Ubuntu, and CentOS have been hit or miss.  I decided to be a little more 
adventurous with Fedora 19.

I decided to use livecd-iso-to-disk.sh so that I could know better what 
was going on.

(Is it time to change the name?  Fedora Live no longer fits on a CD
these days.  It's great on DVDs and USB sticks.)

I wanted a LARGE overlay (I wanted to experiment with installing 
updates).  When I tried
    sudo ./livecd-iso-to-disk.sh --format --overlay-size-mb 4095 --home-size-mb 200 --unencrypted-home Fedora-Live-Desktop-x86_64-19-1.iso /dev/sdi
it tried to create an MSDOS filesystem and consequently complained
that it was too big:
    mkfs.fat 3.0.20 (12 Jun 2013)
    Can't have an overlay of 2048MB or greater on VFAT

Why didn't it use ext[34]?  Reading the script, I found the answer: I
hadn't installed the systlinux-extlinux package on my host system.
There was no message to this effect.

I suggest something like this (untested!) patch be applied:

==== start
diff --git a/tools/livecd-iso-to-disk.sh b/tools/livecd-iso-to-disk.sh
index c4fb4db..0e65d3e 100755
--- a/tools/livecd-iso-to-disk.sh
+++ b/tools/livecd-iso-to-disk.sh
@@ -868,7 +868,10 @@ if [ -n "$format" -a -z "$skipcopy" ]; then

if [ -n "$efi" ]; then
         createGPTLayout $TGTDEV
-    elif [ -n "$usemsdos" -o ! -x /sbin/extlinux ]; then
+    elif [ -n "$usemsdos" ]; then
+        createMSDOSLayout $TGTDEV
+    elif [ ! -x /sbin/extlinux ]; then
+        echo "Warning: syslinux-extlinux package not installed; formatting as VFAT filesystem instead of EXT"
         createMSDOSLayout $TGTDEV
     else
         createEXTFSLayout $TGTDEV
==== end

[Brian C. Lane]

On Sat, Jul 06, 2013 at 03:06:00PM -0400, D. Hugh Redelmeier wrote:
> Why didn't it use ext[34]?  Reading the script, I found the answer: I
> hadn't installed the systlinux-extlinux package on my host system.
> There was no message to this effect.

How did you install it? The rpm requires /sbin/extlinux so normally it
should already be installed?

[D. Hugh Redelmeier]

| From: "Brian C. Lane"

| On Sat, Jul 06, 2013 at 03:06:00PM -0400, D. Hugh Redelmeier wrote:
| 
| > Why didn't it use ext[34]?  Reading the script, I found the answer: I
| > hadn't installed the systlinux-extlinux package on my host system.
| > There was no message to this effect.
| 
| How did you install it? The rpm requires /sbin/extlinux so normally it
| should already be installed?

Well, I was reading https://fedoraproject.org/wiki/LiveOS_image and
found a reference to
http://git.fedorahosted.org/cgit/livecd/tree/tools/livecd-iso-to-disk.sh
so I fetched that and ran it.

I now realize that I was supposed to have installed livecd-tools.rpm.

Anyway, it seemed to run fine except for this (silent) problem.

[D. Hugh Redelmeier]

| From: Brian C. Lane 
| 
| On Sat, Jul 06, 2013 at 03:06:00PM -0400, D. Hugh Redelmeier wrote:
| 
| > Why didn't it use ext[34]?  Reading the script, I found the answer: I
| > hadn't installed the systlinux-extlinux package on my host system.
| > There was no message to this effect.
| 
| How did you install it? The rpm requires /sbin/extlinux so normally it
| should already be installed?

It looks like you aren't going to accept my patch to warn when 
/sbin/extlinux isn't present.  Fair enough: "Can't happen".

If it cannot happen, I recommend that you remove the "-o ! -x
/sbin/extlinux" from
    elif [ -n "$usemsdos" -o ! -x /sbin/extlinux ]; then

That way an error message will be generated by the shell in the impossible
case (that would have helped me).  And the script becomes simpler.