[Libguestfs] libguestfs fails on FreeBSD9.3, MINIX3 qcow2 images

[Richard W.M. Jones]

On Thu, Sep 18, 2014 at 03:38:05PM -0400, Assaf Gordon wrote:
> 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%
> =====

virt-df should never print negative numbers like this.  So this is a
bug -- please file it using the link from the http://libguestfs.org
front page.

> -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
> =====

This one is a fairly well-known problem in the Linux kernel / *BSD
filesystem.  See:

  http://libguestfs.org/guestfs-faq.1.html#ufs-disks-as-used-by-bsd-cannot-be-opened

There's no good answer to this except for BSD to start properly
identifying all the variants of UFS.

Rich.

-- 
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