Overlay File Health?

[Kam Salisbury]

How do I see how much space is used in the overlay file (Fedora USB)?

[liveuser@localhost ~]$ df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/live-rw   3.0G  2.2G  771M  75% /
tmpfs                1013M  288K 1013M   1% /dev/shm
/dev/sdb1              15G  8.3G  6.8G  55% /mnt/live
varcacheyum          1013M     0 1013M   0% /var/cache/yum
/tmp                 1013M  104K 1013M   1% /tmp
vartmp               1013M     0 1013M   0% /var/tmp

The above command output does not seem to reflect the 2GB overlay.

Is there a way to output "just" the overlay contents? Something like 'du
-hs' (du shows what /dev/mapper shows).


-- 
Kam Salisbury
http://kamsalisbury.com
GPG key: FAF1751E

[Forrest Taylor]

On Wed, 2009-01-14 at 06:42 -0500, Kam Salisbury wrote:
>  How do I see how much space is used in the overlay file (Fedora
> USB)?
>  
>  [liveuser@localhost ~]$ df -h 
I also have a question regarding the overlay, that will probably be
answered by whomever answers your question.  Is the overlay ever used?
The /home directory is setup using the live script, but the overlay is
never setup as far as I can see.  Is it meant to be used to add disk
space to the root directory?

Thanks,
-- 
Forrest Taylor
Global Learning Services Project Manager III
Cell: 303-913-5169
AIM: forresttaylorred
Red Hat IRC: forrest

[Forrest Taylor]

On Wed, 2009-01-14 at 06:42 -0500, Kam Salisbury wrote:
>  How do I see how much space is used in the overlay file (Fedora
> USB)?
>  
>  [liveuser@localhost ~]$ df -h
>  Filesystem            Size  Used Avail Use% Mounted on
>  /dev/mapper/live-rw   3.0G  2.2G  771M  75% /
>  tmpfs                1013M  288K 1013M   1% /dev/shm
>  /dev/sdb1              15G  8.3G  6.8G  55% /mnt/live
>  varcacheyum          1013M     0 1013M   0% /var/cache/yum
>  /tmp                 1013M  104K 1013M   1% /tmp
>  vartmp               1013M     0 1013M   0% /var/tmp
>  
>  The above command output does not seem to reflect the 2GB overlay.
>  
>  Is there a way to output "just" the overlay contents? Something like 'du
> -hs' (du shows what /dev/mapper shows). 
Kam,

I wrote a script to check the status of the overlay (attached).  I'll
see if I can get it included for future use.

-- 
Forrest Taylor
Global Learning Services Project Manager III
Cell: 303-913-5169
AIM: forresttaylorred
Red Hat IRC: forrest

[Stewart Adam]

On 1/27/09 9:21 AM, Forrest Taylor wrote:
>  On Wed, 2009-01-14 at 06:42 -0500, Kam Salisbury wrote:
> > How do I see how much space is used in the overlay file (Fedora USB)?
> >
> > [liveuser@localhost ~]$ df -h
> > Filesystem            Size  Used Avail Use% Mounted on
> > /dev/mapper/live-rw   3.0G  2.2G  771M  75% /
> > tmpfs                1013M  288K 1013M   1% /dev/shm
> > /dev/sdb1              15G  8.3G  6.8G  55% /mnt/live
> > varcacheyum          1013M     0 1013M   0% /var/cache/yum
> > /tmp                 1013M  104K 1013M   1% /tmp
> > vartmp               1013M     0 1013M   0% /var/tmp
> >
> > The above command output does not seem to reflect the 2GB overlay.
> >
> > Is there a way to output "just" the overlay contents? Something like
> 'du -hs' (du shows what /dev/mapper shows).
>
>  Kam,
>
>  I wrote a script to check the status of the overlay (attached).  I'll
>  see if I can get it included for future use. 
Has anyone else had the overlay become
corrupted when it gets full? I had 
this problem too... df -h said I had a bunch of free space so I installed 
lots of extra packages but then I got a error message saying "read only 
filesystem" I after that I couldn't run "rm" or even "ls".
When I rebooted 
from the USB key again, it complained about logical buffer errors and I had 
to regenerate the overlay to fix it.

Stewart

[Forrest Taylor]

On Tue, 2009-01-27 at 09:45 -0500, Stewart Adam wrote:
>  On 1/27/09 9:21 AM, Forrest Taylor wrote:
>  > On Wed, 2009-01-14 at 06:42 -0500, Kam Salisbury wrote:
>  >> How do I see how much space is used in the overlay file (Fedora USB)?
>  >>
>  >> [liveuser@localhost ~]$ df -h
>  >> Filesystem            Size  Used Avail Use% Mounted on
>  >> /dev/mapper/live-rw   3.0G  2.2G  771M  75% /
>  >> tmpfs                1013M  288K 1013M   1% /dev/shm
>  >> /dev/sdb1              15G  8.3G  6.8G  55% /mnt/live
>  >> varcacheyum          1013M     0 1013M   0% /var/cache/yum
>  >> /tmp                 1013M  104K 1013M   1% /tmp
>  >> vartmp               1013M     0 1013M   0% /var/tmp
>  >>
>  >> The above command output does not seem to reflect the 2GB overlay.
>  >>
>  >> Is there a way to output "just" the overlay contents? Something like
> 'du -hs' (du shows what /dev/mapper shows).
>  >
>  > Kam,
>  >
>  > I wrote a script to check the status of the overlay (attached).  I'll
>  > see if I can get it included for future use.
>  Has anyone else had the overlay become corrupted when it gets full? I had 
>  this problem too... df -h said I had a bunch of free space so I installed 
>  lots of extra packages but then I got a error message saying "read only 
>  filesystem" I after that I couldn't run "rm" or even "ls".
> When I rebooted 
>  from the USB key again, it complained about logical buffer errors and I had 
>  to regenerate the overlay to fix it. 
Yeah, that is what happens when you fill up the overlay.  df really
isn't a valid measure of the space that you can use.  You should use a
larger overlay if you want to use more disk space.  I've been toying
with the idea of using multiple overlay files (e.g., on FAT you cannot
have files larger than 2GB), but it seems more work than it is worth at
this time.

BTW, instead of regenerating the overlay, you can clear it out by
booting the LiveUSB using the reset_overlay kernel option.

-- 
Forrest Taylor
Global Learning Services Project Manager III
Cell: 303-913-5169
AIM: forresttaylorred
Red Hat IRC: forrest