Re: [uml-user] sparse files as root images

[<ro...@mm...>]

richard -rw- weinberger wrote:
> Hi,
>
> On Mon, Dec 5, 2011 at 7:20 PM,  <ro...@mm...> wrote:
>> dd if=/dev/zero of=$OUTFS bs=1024 count=1 seek=$((20*1024*1024-1))
>
> Does it work if the filesystem is not sparse?

After all, it doesn't seem this to be the problem.

Today I started from scratch in a different machine having:
OS: Slackware.12.2
RAM: 512MB

I compiled kernel.3.1.2 for ARCH=um, built a 5GB sparse file as an image
and a 1GB non-sparse for swap.
Installed Slackware.12.2 into the 5GB sparse file.
Executed 'make modules_install INSTALL_MOD_PATH=/mnt/sparse-file ARCH=um'.
Installed fstab thus:
----
/dev/ubdb        swap             swap        defaults         0   0
/dev/ubda        /                ext3        defaults         1   1
#/dev/cdrom      /mnt/cdrom       auto        noauto,owner,ro  0   0
#/dev/fd0         /mnt/floppy      auto        noauto,owner     0   0
devpts           /dev/pts         devpts      gid=5,mode=620   0   0
proc             /proc            proc        defaults         0   0
tmpfs            /dev/shm         tmpfs       defaults         0   0
---
and fired UML with:

./linux ubda=uml_fs ubdb=uml_fs_swap mem=xxxM

trying 64, 128, 384, 448 and 512 as values for mem.

No problems whatsoever. I even started mysql and played around for a while.

I realize this is a different configuration than the one I was having
issues with. Is it possible though that my fstab is somehow not 'correct'?

Anyway, I won't have access to the machine that gave troubles until
Monday, so I can't be more specific.

Thank you for your interest,
-Stathis

>
>> but I'm having kernel panics (not syncing) whenever I try to run various
>> commands inside UML.
>
> Please post the complete panic.
>
>> So far I got kernel panics with top and updatedb.
>>
>> Please consider that I am able to boot into UML. The trouble begins when
>> I'm trying to actually use the beast.
>>
>> Background:
>> kernel.3.1.4, built with defconfig ARCH=um
>> host OS = Slackware.13.37
>> Guest OS = Slackware.13.37
>> Host RAM=256MB
>> Guest RAM= mem=128M
>
> What is the exact command line?
>
> --
> Thanks,
> //richard
>