Topic: MBR Bootable flag bass-ackwards in Gparted?
The Gparted online documentation says that the bootable flag for a partition is "used by some commercial operating system boot loaders":
http://gparted.org/display-doc.php?name … tion-flags
While accurate, this is not the whole story. I happen to own a motherboard (Gigabyte GA-M55Plus-S3G) whose BIOS is also sensitive to this flag on a partition. It refuses, quite reasonably, I believe, to list a device in its Hard Disk Boot Priority list unless the drive (or USB stick) in question contains at least one MBR partition with the bootable flag set. For this reason, the status of this flag, in various partitions, is of keen interest to me.
I am currently using GParted 0.16.1, as present within the Ultimate Boot CD 5.2.7 release. I am aware that this is not 100% current, but it is close, and I do suspect that the behavior of 0.16.1 is probably indicative of the behavior of the current 0.17.0 release.
Today, I have been performing numerous tests, with Gparted, with my GA-M55Plus-S3G, and with various drives that I own. The bottom line is that my findings are indicating to me, quite clearly, that if there is a check mark next to the "boot" flag, as displayed by Gparted, then all other indications are that the relevant partition is in fact not, I repeat, not actually marked as bootable, and conversely, that if Gparted displays the "boot" flag without a check mark next to it, then the relevant MBR partition is in fact marked as bootable.
I intend to report this formally as bug in GParted, however I felt it best to report this finding here first, in case anyone wishes to dispute my finding. If anyone does, then I'll be more than happy to describe, at least, the tests I've done and the evidence I have gathered, all of which appears to me to be compelling.
P.S. The most compelling evidence (but not to the only evidence) which supports my conclusion (i.e. that GParted is in fact displaying the negation of the actual bootable flag) is that GParted, when displaying these flags for a perfectly working, bootable hardrive with a full Windows7 install on it, is showing the Windows recovery partition with the bootable flag checked and is showing the actual Windows7 OS partition with the bootable flag not checked. Additionally, the BIOS of my GA-M55Plus-S3G declines to list in its Boot Priority list a USB stick containing a single MBR partition that GParted shows with the "boot" flag checked, however if that flag is manually unchecked, using Gparted, and then the USB stick is inserted into the GA-M55Plus-S3G, then the BIOS does list the USB stick itself on its Boot Priority list.
It may perhaps be the case that both Windows 7 and my Gigabyte motherboard are getting things bass-ackwards, and that GParted is the only one telling the true story with respect to the status of this (bootable) flag, but that seems a bit unlikely.