Instant reboot with FreeBSD 6.3 and > 2GB RAM

[Volker]

On 12/23/-58 20:59, votdev at gmx.de wrote:
> Hello,
> 
> some users of FreeNAS which is based on FreeBSD 6.3 reported instant reboots on systems with > 2GB RAM (most of them use 4GB). The reboot occurs right after displaying the FreeBSD loader menu. Most of them told me that they can boot if they reduce RAM to <= 2GB.
> 
> We are using the following kernel configuration which is based on GENERIC:
> http://freenas.svn.sourceforge.net/viewvc/freenas/branches/0.69/build/kernel-config/FREENAS-i386?revision=3291&view=markup
> 
> I found out another problem that causes a reboot on my 2GB machine. We are using a image for the LiveCD which is 64MB great. If i change back mfs_root size to 63MB all works well, but all above 64MB causes a reboot.
> Is there any limitation?
> 
> Could someone help me out of this problem?
> 
> Regards
> Volker

Hi Volker ;)

I'm not quite sure about your 2nd problem and your report is not quite
detailed but from your description it looks like loader is causing that.
As there's no filesystem available at that time, the loader has to read
itself through the filesystem structures.

Knowing that, PR misc/108215 comes to mind. I've not been able to check
if the issue and the patch to it is right but you may give it a try.
Probably somebody with loader and filesystem (ufs) knowledge may answer
that question quickly if the patch contained in the PR is right.

The report is about 6.2-R but at least I've checked loader code and 7.x
code is the same. I came across that report yesterday and was unable to
check the calculation.

If that is really the case, your problem may be related to that.

http://www.freebsd.org/cgi/query-pr.cgi?pr=108215

Assuming the problem report is right, it's about reading huge files by
loader reads in wrong sectors.

HTH

Volker