Bootable partitions

[Ben Scott]

On 3/13/06, Paul Lussier <p.lussier at comcast.net> wrote:
>> I don't think it matters, not if you have LILO or GRUB in the MBR.
>
> Then what's the point of this flag?  Is it merely a legacy thing which
> used to mean something before (somewhat) intelligent bootloaders came
> along?

  Continuing from my previous message...

  Setting the active primary partition allowed one to select which
partition to boot in an OS-independent fashion.  This was consider a
fairly radical idea on the IBM-PC platform in the mid 1980's.  :)

  If you are using GRUB or LILO to replace the standard MBR, the
active flag has no effect.

  If you are *not* doing that (i.e., you have GRUB/LILO installed in a
PBR), the active flag still controls which PBR gets booted, so it
*does* matter in that case.  There are reasons to do this.  The
"install the boot loader in the MBR" introduces non-standard behavior.
 Now, the IBM-PC platform is pretty much hopeless from the standpoint
anyway, but sometimes one cares.  In particular, some manufacturers
(notably Compaq (now HP, I guess)) provide diagnostics and utilties in
a separate partition, and keeping that partition bootable via the
"standard" means is often important.

  The active flag also influences drive letter ordering under various
non-Linux OSes (not so much modern Windoze, but the older stuff), but
I assume you don't care about that.

-- Ben