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The importance of Unattended Guest OS Installs

PostPosted: 8. Jul 2011, 20:19
by Technologov
Copyright (C) 2011. Alexey Eromenko "Technologov"

The importance of Unattended Guest OS Installs

One killer feature, that we still lack as compared to the competition is
Automatic / Unattended installtion of Guest OS. (Wish #5810)

There is simply no reasons why millions of users should waste millions of hours, collectively, when such job can clearly be done by computers.

Performance benefits: (on modern Core2-class hardware)
Installing Windows XP by coffee-drinking people takes about 30 min
Installing Windows XP by active geek, clicking instantly takes about 15 min
Installing Windows XP by Unattended Install, takes about 10 min, letting people to drink coffee in first place.

Unattended Install eliminates many steps -- they are simply skipped. Those, that aren't skipped (such as formatting and copying) are near-instant.

All Major OSes have built-in mechanism for this (Windows Unattended Setup,
Red Hat Anaconda, SUSE AutoYast, etc...)
So I won't speak about re-inventing the wheel, but about using the already existing wheel properly.
This single major feature saves countless hours for both newbies and advanced users alike. BETA testing also occur *much* faster this way, improving product quality.

What is needed -- is to integrate between this GuestOS-family-specific procedure and VirtualBox.
VirtualBox should, on the fly, create the necessary GuestOS-family-specific startup scripts,
and boot the new VM from them.

When I say GuestOS-family, it means, that once we implement WinNT 5.x backend,
we automatically support Win2000/WinXP/WinXP.x64/Win2003/Win2003.x64 OSes.
Same for Red Hat Anaconda: one good backend can support everything from RHEL3 to latest Fedoras,
including Oracle Linux and CentOS in between.

Let's Analyze the typical of automatically installed Windows XP:
1. New VM is created with 1 HDD (unformatted), 1 CD-ROM (WinXP) and 1 floppy

This floppy contains the Unattended Setup script, "winnt.sif",
which describes everything (how to format drive, what to install, what to config, etc...), including CD-Key.

All VirtualBox has to do, is to create the needed unattended setup script on-the-fly, then write it to media
and insert the media.

In case of Windows XP, the "VBox Unattended Setup" wizard should ask for CD-Key,
User name (+optional password) and Company name.
Then VBox should create "winnt.sif", describing this procedure in a language WinXP setup can understand.
Then "winnt.sif" must be written to a formatted FAT12 floppy image.
Then the floppy image must be inserted as drive A:.
Boot order is critical ! It must be: Hard Disk->CD-ROM->Floppy.

I can provide a good example "winnt.sif" scripts for NT 5.x family.

Red Hat Linux case:
This one is more complex than Win XP, because it doesn't have the option to
just inject simple script into floppy.
It requires modified "initrd" to install in unattended mode, which can be
loaded via PXE, or CD-ROM ISO or via Direct Linux Boot.
This one can affect how Anaconda Setup works.

I have only basic understanding of initrd scripting, and no good examples.

VBox lacks certain preconditions for this major feature to happen, namely:
#1. Floppy emulation from host filesystem (Wish #7836)
#2a. Create CD ISO on the fly (Wish #1970)
#2b. Direct Linux Boot (Wish #8401)

VMware Workstation 7.x simply ships pre-compiled "mkisofs.exe" on Windows hosts
solving precondition #2a. It also ships with pre-compiled binary for #1.

Qemu has preconditions #1 and #2b integrated directly into qemu.exe. (no separate binary)

Competing products with those features:
-Qemu/KVM - KVM Autotest add-on.
-VMware Workstation 6.5 (and above)
-Parallels Desktop/Workstation

With the best implementation being VMware.

Discuss this topic on:

-Technologov, 08.Jul.2011.

Re: The importance of Unattended Guest OS Installs

PostPosted: 17. Jul 2011, 04:19
by Technologov