Libguestfs - Sep 2014 - libguestfs fails on FreeBSD9.3, MINIX3 qcow2 images

Hello Richard and all,

(continuing from
https://www.redhat.com/archives/libguestfs/2014-September/msg00112.html ).

I'm experimenting with libguestfs on non-linux VMs, encountered errors on
FreeBSD9.3 and MINIX3 (and few others, but these ones are easy to share), with
host Ubuntu 14.04.01 LTS x86-64.

Attached are logs from "virt-inspector -v -x" for each VM.

The images are here:
   http://files.housegordon.org/libguestfs/minixR330.qcow2.clean_install.xz
(44MB)
   http://files.housegordon.org/libguestfs/freebsd93.qcow2.clean_install.xz
(161MB)

To run them:
   xz -dc < minix3/minixR330.qcow2.clean_install.xz > minixR330.qcow2
   kvm -drive file=minixR330.qcow2,if=virtio,media=disk,index=0 \
       -m 384 -curses -net user -net nic,model=virtio

   xz -dc < freebsd93.qcow2.clean_install.xz > freebsd93.qcow2
   kvm -drive file=freebsd93.qcow2,if=virtio,media=disk,index=0 \
       -m 384 -curses -net user -net nic,model=virtio

Root password for freebsd is "12345".
Root in Minix does not require a password.


Regards,
  - Assaf


==== Disk structure from within MINIX3 VM guest ===# fdisk /dev/c0d0
Geometry of /dev/c0d0: 10402x16x63
Inconsistent size in partition 1.
Suspect head and sector parameters.
Disk appears to have mis-specified number of heads or sectors.
Try  fdisk -h256 -s63 /dev/c0d0  instead of
fdisk -h16 -s63 /dev/c0d0
Do not write the table if you are not sure!.

----first----  -----last----  --------sectors-------
Num Sorted Act  Type     Cyl Head Sec   Cyl Head Sec    Base    Last    Size
1     1    A   MINIX        0   1   1    649 255   63      63+10483199 10483137
-
2     2        None         0   0   0      0   0    0       0       0       0
3     3        None         0   0   0      0   0    0       0       0       0
4     4        None         0   0   0      0   0    0       0       0       0

# df
Filesystem    512-blocks       Used      Avail %Cap Mounted on
/dev/c0d0p0s0    4194304     111632    4082672   2% /
none                   0          0          0 100% /proc
/dev/c0d0p0s2    3831200     805792    3025408  21% /usr
/dev/c0d0p0s1    2457600      25784    2431816   1% /home
none                   0          0          0 100% /sys

# mount
/dev/c0d0p0s0 on / type mfs (rw)
none on /proc type procfs (rw)
/dev/c0d0p0s2 on /usr type mfs (rw)
/dev/c0d0p0s1 on /home type mfs (rw)
none on /sys type devman (rw)


====== Disk structure from within FreeBSD 9.3 VM guest =====# df
Filesystem   1K-blocks   Used   Avail Capacity  Mounted on
/dev/vtbd0p2   4818524 777212 3655832    18%    /
devfs                1      1       0   100%    /dev

# mount
/dev/vtbd0p2 on / (ufs, local, journaled soft-updates)
devfs on /dev (devfs, local, multilabel)

# fdisk /dev/vtbd0
******* Working on device /dev/vtbd0 *******
parameters extracted from in-core disklabel are:
cylinders=10402 heads=16 sectors/track=63 (1008 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=10402 heads=16 sectors/track=63 (1008 blks/cyl)

Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 238 (0xee),(EFI GPT)
start 1, size 10485759 (5119 Meg), flag 0
beg: cyl 0/ head 0/ sector 2;
end: cyl 1023/ head 255/ sector 63
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>

On Thu, Sep 18, 2014 at 11:38:09AM -0400, Assaf Gordon
wrote:
> Hello Richard and all,
> 
> (continuing from
https://www.redhat.com/archives/libguestfs/2014-September/msg00112.html ).
> 
> I'm experimenting with libguestfs on non-linux VMs, encountered errors
on FreeBSD9.3 and MINIX3 (and few others, but these ones are easy to share),
with host Ubuntu 14.04.01 LTS x86-64.
> 
> Attached are logs from "virt-inspector -v -x" for each VM.
Thanks -- both of these are inspection bugs.  I have filed there here:

https://bugzilla.redhat.com/show_bug.cgi?id=1144137
https://bugzilla.redhat.com/show_bug.cgi?id=1144138

Note that you can do useful things with libguestfs without necessarily
needing inspection to work.  Libguestfs will open any disk image, but
without inspection you won't be able to detect OSes in the disk image
nor map devices to mountpoints, unless you do it yourself.

The first bug (Minix) is likely quite easy to fix actually.  I suspect
that adjusting this function would do it:

https://github.com/libguestfs/libguestfs/blob/master/src/inspect-fs-unix.c#L1489

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top

Hello Richard,

On 09/18/2014 02:47 PM, Richard W.M. Jones wrote:
> Note that you can do useful things with libguestfs without necessarily
> needing inspection to work.  Libguestfs will open any disk image, but
> without inspection you won't be able to detect OSes in the disk image
> nor map devices to mountpoints, unless you do it yourself.
Two more related issues:

-1-
With minix, "virt-df" returns negative values:

====$ virt-df -a ./minixR330.qcow2
Filesystem                           1K-blocks       Used  Available  Use%
minixR330.qcow2:/dev/sda5              2075188      11892    2063296    1%
minixR330.qcow2:/dev/sda6              1215924     -94776    1310700   -7%
minixR330.qcow2:/dev/sda7              1895536     312296    1583240   17%
====

-2-
With the FreeBSD, "guestfish" can't mount the "ufs"
filesystem:
====$ guestfish -a ./freebsd93.qcow2
><fs> run
><fs> list-filesystems
/dev/sda1: unknown
/dev/sda2: ufs
/dev/sda3: unknown
><fs> mount-ro /dev/sda2 /
libguestfs: error: mount_ro: /dev/sda2 on / (options: 'ro'): mount:
wrong fs type, bad option, bad superblock on /dev/sda2,
        missing codepage or helper program, or other error
        In some cases useful info is found in syslog - try
        dmesg | tail  or so
====
The "dmesg" (from without guestfish) shows this:
====[   17.052574] You didn't specify the type of your ufs filesystem
[   17.052574]
[   17.052574] mount -t ufs -o
ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|nextstep-cd|openstep ...
[   17.052574]
[   17.052574] >>>WARNING<<< Wrong ufstype may corrupt your
filesystem, default is ufstype=old
[   17.068725] ufs_read_super: bad magic number
=====

Hello Assaf,

On Thursday 18 September 2014 11:38:09 Assaf Gordon
wrote:
> I'm experimenting with libguestfs on non-linux VMs, encountered errors
> on FreeBSD9.3 and MINIX3 (and few others, but these ones are easy to
> share), with host Ubuntu 14.04.01 LTS x86-64.
Thanks for the images!

Now with recent versions of libguestfs (>= 1.27.53, currently to be 
released yet), a basic Minix detection is done.
For further details, see
  https://bugzilla.redhat.com/show_bug.cgi?id=1144137
(feel free to subscribe to it).

-- 
Pino Toscano