Re: qemu test with start_vm fails

[Henning Schild <henning.schild@siemens.com>]

Am Fri, 30 Nov 2018 10:06:39 +0100
schrieb "[ext] Henning Schild" <henning.schild@siemens.com>:

> Am Thu, 29 Nov 2018 13:20:17 +0100
> schrieb Andreas Reichel <andreas.reichel.ext@siemens.com>:
> 
> > On Wed, Nov 28, 2018 at 08:34:58PM +0300, Maxim Yu. Osipov wrote:  
> > > Hi Andreas,
> > > 
> > > I would suggest to double check your statements before blaming
> > > that something is not working
> > >     
> > Hi,
> > 
> > well unfortunately I was correct. There is an error in Isar:
> > the offline cache is included in the root file system :)
> > 
> > There is a /base-apt in the resulting .ext4.img.
> > 
> > This way I got a rootfs of 720 MB with no free space, despite the
> > 64M extra space. (file system overhead).  
> 
> I think we now have a fix because we do not include the cache into the
> image anymore. But that actually just hides the bug we have in the
> ext4 class, next time someone builds a 700M image the same thing will
> happen again.
> 
> So we will also need a patch that prepares the ext4 for that case.
> Things that could be done
>  - mkfs -m 1 (instead of default 5)
>  - multiply the size with an ext4 specific overhead factor
>  - df assert the EXTRA while still mounted
>  - double check what wic is doing, maybe use wic instead of ext4

In addition the "cp -r" will drop a lot of file attributes and should
be "cp -a". In fact it would be best to "mkfs.ext4 -d", like wic.
Using wic would result in a disk and not in a partition image, but that
should not be a problem. Older mkfs.ext4 versions do not support "-d",
maybe we need to finally drop that old raspbian ... 

Henning

> Henning
> 
> > In your CI you obviously do not use the offline cache feature,
> > that's why in CI this did not happen.
> > 
> > vG
> > Andreas  
>