Installer: no option to set geometry/corrupts partition table
randux at noreply.org
randux at noreply.org
Sun Mar 4 10:27:09 PST 2007
Matthew Dillon wrote:
:I installed the 1.8.0 release from the liveCD and it screwed up my
:partition table. How can I set the drive geometry so that the installer
:will use my c/h/s values instead of the (possibly incorrect) values said
:to be obtained from BIOS?
:I noticed this problem in FreeBSD but it seems to have been mitigated by
:the installer offering a "G" option to set drive geometry around 6.1/6.2
:release, not sure exactly when.
:I posted a question on the users list on Feb. 26 but hearing nothing
:(and wanting to install Dfly 1.8.0 release) I am posting here on bugs.
:Someone with a multiboot setup who doesn't track changes to his
:partition table can suffer loss of data because of this error. It could
:be a relatively serious problem, especially for newbies to multibooting
:as symptoms probably won't appear immediately, it will be difficult to
Hmm. usually that sort of problem is due to the disk mode in the
BIOS setup not being set to Large or logical block mode. Nobody
has used CHS in a long time, and BIOSes still get confused by faked
<dillon at backplane.com>
There needs to be an option such as FreeBSD (and NetBSD and iirc
OpenBSD) are providing, to set c/h/s for use by the DFly installer. I
don't understand the comment that nobody is using it- all the *BSD show
their view of it and if it doesn't match the partition table (which is
laid out to this day in terms of c/h/s whether it's actual or virtual)
it causes problems.
For example, my machines are set up with 255 heads 63 sectors and how
ever many cylinders the drive maps to. I fdisk the drive and I create
my partitions aligned on cylinder boundaries. When DFly installs it uses
16 heads and some other factor for sectors. He changed the units on the
partition table and this means that the partitions I had created before
and after (locations, not times) the DFly target slice are no longer on
integral boundaries, and that writing on the DFly filesystems can leak
into my other partitions and corrupt data.
There should be a simple way to set the c/h/s in the installer.
Otherwise it does not play nice in a multiboot scenario.
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