[Qemu-devel] RE: qemu debian etch

[Juergen Pfennig]

Hi,
win2003 (and as you say win XP) does not detect the media change.
As a consequence the cached data gets not flushed (inside win).
The "change cd /dev/cdrom" sometimes caused a qemu crash for me.

So you probably found a bug. If nobody else solves the problem it
will stay on my list as a low priority problem.

TIP: mount your cd rom (images) via loopback and export them via
smb (allow samba to follow symlinks and use simple ln -s commands
to point to your mount points). Evidently you need a working win
to do this. For (ms) win apps you don't need the iso images, just
do what ms calls an "administrative install" to your smb server.
Administrative installs are compatible with wine (if you like
that) and can be shared from multiple clients (e.g. also saving
disk space).

TIP: to install windows (from MSDN cds) ... step (1) install a
minimal system from a bootable cd. (2) make sure that the vm
can access your smb server. (3) create a "slip stream" image of
the win and SP you want to install on your smb server. (4) making
an MSDN cd bootable will often be a problem - don't try it if you
don't know better. (5) From your running vm re-install the (slip
stream) win that you want via smb. (6) You should not go the other
way round (installing a SP on the VM), which takes longer and 
wastes disk space. (7) start your VM with -vga to activate windows
(8) configure your WSUS or other update mechanism and let it 
install the official patches from MS.

TIP: don't panic. At least for win2003 the disk io can degenerate
completely so that a login can take 75s. Sometimes it helps to
run a disk-defrag (but stop it after a minute or so, otherwise
it fills your virtual disk with crap). Here some figures for a
P4 2.4 GHz and 1GByte memory (qemu -m 300 with kqemu used):

(1) win2003 takes about 60s to boot (a factor of 2-3)
(2) a login takes 6s (a factor of 3)
(3) old COM based apps like Word have a "slow down" factor of 3
(4) .NET apps seem to run a little faster (VS 2003 is usable)
(5) IO is a problem. Don't expect more than 5 MByte/s

Win XP/2003 are a least usable and the cd rom bug is not so dramatic.
It's also not a Debian problem.
Yours Jürgen