[Libguestfs] virt-ls windows

[Richard W.M. Jones]

On Fri, Aug 03, 2012 at 10:53:53AM +0300, Evaggelos Balaskas wrote:
> In our infrastructure we have some users that dont understand about
> the basics and are keep writing small descriptions for file names !
> 
> an example is below, the name is in Greek
> 
> tar: ./Desktop/ΔΗΜΗΤΡΗΣ/ΣΥΝΤΕΛΕΣΤΕΣ ΑΠΟΣΒΕΣΗΣ Νέοι συντελεστές
> απόσβεσεις πάγιων περιουσιακών στοιχείων Οι συντελεστές απόσβεσης,
> ανώτεροι και κατώτεροι που προβλέπει το ΠΔ για κάθε είδος
> επιχειρηματικής δραστηριότητας.htm: Cannot open: File name too long
> 
> tar: Exiting with failure status due to previous errors

I looked into this more closely and it turns out that it's the tar
subprocess running *on the host* which fails.

The reason is clear: it's because the host filesystem (eg. ext4)
doesn't support a filename of this length.  ext2/3/4 supports
filenames of up to 255 bytes.  However because this filename contains
UTF-8 chars which (in this case) are encoded as 2 bytes each, your
~200 character filename is really ~400 bytes, and that is too long.

If you switched to a different host filesystem[1] then you'd be able
to do this.

Or keep your backup as a tarball (ie. replace 'copy-out' with
'tar-out'), since GNU tar can store unlimited length filenames.

We will probably document this issue, but I don't think this is a bug
in libguestfs.

Rich.

[1] eg: exFAT, NTFS, reiser are the only likely candidates.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-df lists disk usage of guests without needing to install any
software inside the virtual machine.  Supports Linux and Windows.
http://et.redhat.com/~rjones/virt-df/