[OpenIndiana-discuss] A few words about multiple operating systems with OpenIndiana

[Robin Axelsson]

During my install I have run into some problems that I resolved so I 
think it is suitable to mention these solutions here:

When you have several operating systems in one system there are a few 
things to consider when resolving conflicts that may occur when 
installing updates and service packs which I will walk you through here.

Before we go on about installation a few words about the master boot 
record is in place here. When you partition a boot hard drive, one of 
these primary partitions is the boot partition, i.e. the partition the 
BIOS will choose to boot from when the system is set to boot from that 
particular disk. This is managed by a set of flags that let the BIOS 
identify the purpose of each partition. The flag that is used to 
identify the boot partition is called the "active" flag or "boot" flag. 
This flag is set whenever you "Mark" a given partition as "active" in 
the disk management tool in Windows or tick the "boot" flag in the 
gparted tool that comes with the OpenIndiana LiveCD. Only one partition 
on a hard drive can be flagged as active, so activating one partition 
means that another partition is deactivated. Usually this is handled by 
the installers so you generally don't have to worry about it, unlesss 
you run into problems we will discuss below.

Let's say that you want to have three different operating systems on 
your system hard drive on three separate partitions. Let us assume that 
you want to have Windows XP x64, Windows 7 x64 and OpenIndiana installed 
each having its own 50GB partition to play around with and you install 
them in the order given.

So you begin by installing WinXP x64, a primary 51200MB partition is 
created and WinXP is installed into it, that's it. This partition will 
automatically be flagged as the active partition.

Then you install Windows 7 x64 on another primary partition of the same 
size after the WinXP partition. What happens is that the Win7 installer 
modifies the WinXP partition by adding a special boot menu that lets you 
choose between Win7 and WinXP. The partition with Windows 7 in it is not 
bootable and has no "ntloader" to boot. So the WinXP partition remains 
the _active_ system partition.

Then you move on to install OpenIndiana on another partition created by 
the gparted tool on the OI LiveCD. The OI installer detects the two 
Windows partitions and configures grub to let you choose between the 
three operating systems. One of the "Windows" choices however is not 
viable because as we have stated, the Win7 partition is not bootable. It 
has to be accessed through the boot menu of the WinXP partition. The 
OpenIndiana partition is set by the installer as the active partition 
and the grub boot environment that lets you choose between operating 
systems is located in the OpenIndiana partition.

Now, if you want to install Service Pack 1 into Windows 7, the service 
pack installer will not accept the OpenIndiana partition as the active 
partition and it will fail miserably. The solution is to run the 
computer management -> disk management tool and mark the Windows XP 
partition as active. Then you can install the service pack onto the 
system. Also note that you cannot do more than one change of active 
partition per bootup with the Microsoft disk management tool and it 
cannot mark non-Windows partitions as active. So when all updates are 
finished you need to use e.g. the gparted tool to move the active flag 
back to the OpenIndiana partition. So you can boot up the liveCD and 
tick the "boot" flag of the OpenIndiana partition to revert back to the 
old boot configuration.

If I had this information at hand it would save me many hours of 
troubleshooting.