a boot option to remove the persistent layer and create a new one

hi,

if one used more than the size of the persistent layer,
system becomes corrupted and unusable

one then can remove the layer to restore it to "factory defaults"

but telling people to create a new layer is a but difficult for end users

I suggest adding things to /etc/rc.d/init.d/livesys generated by %post
by replacing

# if we have a persistent /home, then we want to go ahead and mount it
if ! strstr "\`cat /proc/cmdline\`" nopersistenthome && [ -n
"\$homedev" ]
; then
  action "Mounting persistent /home" mountPersistentHome
fi

with

if ! strstr "\`cat /proc/cmdline\`" nopersistenthome && [ -n
"\$homedev" ]
; then
  if ! strstr "\`cat /proc/cmdline\`" resetpersistenthome
    action "Mounting persistent /home" resetPersistentHome
    telinit 6
  else
    action "Mounting persistent /home" mountPersistentHome
  fi
fi


and we also need a small fix in /usr/libexec/mkliveinitrd
just below
for o in `cat /proc/cmdline` ; do
...

resetPersistentHome and resetOverlay should simply check the size of the
img file we want to rest
then remove it then create a new one with the same size

if we want one more step
we may allow user to pass resetoverlay=200 to optionally specify the new
size



BTW: do we really need to sleep 5

    if [ -z "$setup" ]; then
        if [ -n "$devspec" -a -n "$pathspec" ]; then
           echo "Unable to find persistent overlay; using temporary"
           sleep 5
        fi

[Jeremy Katz]

On Friday, March 13 2009, ???????? ???????????? said:
>  if one used more than the size of the persistent layer,
>  system becomes corrupted and unusable
>  
>  one then can remove the layer to restore it to "factory defaults"
>  
>  but telling people to create a new layer is a but difficult for end users 
If you boot with 'reset_overlay', it resets the overlay.
 
[snip]
>  resetPersistentHome and resetOverlay should simply check the size of
> the
>  img file we want to rest
>  then remove it then create a new one with the same size 
Resetting the persistent home seems a little more questionable.  Since
it's just a filesystem image and not the weird dm-snapshot, it's a less
straight-forward call of how/when it could get corrupted and then need
any sort of resetting

Jeremy

hi,

>  On Friday, March 13 2009, ???????? ???????????? said:
> > if one used more than the size of the persistent layer,
> > system becomes corrupted and unusable
> >
> > one then can remove the layer to restore it to "factory defaults"
> >
> > but telling people to create a new layer is a but difficult for end
>  users
>  
>  If you boot with 'reset_overlay', it resets the overlay.
>  
>  [snip] 
I did not know about reset_overlay boot option

I have looked into /usr/libexec/mkliveinitrd
and just saw it
thanks

>  
>  Resetting the persistent home seems a little more questionable.  Since
>  it's just a filesystem image and not the weird dm-snapshot, it's a less
>  straight-forward call of how/when it could get corrupted and then need
>  any sort of resetting
>   
ok, forget about resetting home then

[Williamson Grant]

I think the issue I see is if /home is %100.
i.e.
I login and create a file so home reaches %100 , I get stale nfs error  
messages.
It will no longer let me delete the file. So I need to run something  
like.

This I guess follows on from the mail from yesterday, and there is no  
simple solution, however a home rescue
mode in the startup script, would atleast help some people out.
i.e. from boot rescue_home

losetup /dev/loop7 /mnt/live/LiveOS/home.img
cryptsetup luksOpen /dev/loop7 Test
e2fsck /dev/mapper/Test -y
mount /dev/mapper/Test mnt/
# interactively remove the large file(s)
umount mnt/
cryptsetup luksClose test
losetup -d /dev/loop7


On Mar 16, 2009, at 2:28 PM, Jeremy Katz wrote:

>  On Friday, March 13 2009, ???????? ???????????? said:
> > if one used more than the size of the persistent layer,
> > system becomes corrupted and unusable
> >
> > one then can remove the layer to restore it to "factory defaults"
> >
> > but telling people to create a new layer is a but difficult for end  
> > users
>
>  If you boot with 'reset_overlay', it resets the overlay.
>
>  [snip]
> > resetPersistentHome and resetOverlay should simply check the size  
> > of the
> > img file we want to rest
> > then remove it then create a new one with the same size
>
>  Resetting the persistent home seems a little more questionable.  Since
>  it's just a filesystem image and not the weird dm-snapshot, it's a  
>  less
>  straight-forward call of how/when it could get corrupted and then need
>  any sort of resetting
>
>  Jeremy
>
>  --
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