unable to make a crashdump

[Andrew Gallatin]

Claus Guttesen writes:
 > Hi.
 > 
 > I'm trying to get a crashdump from my kernel when it
 > panics. I have the following in my kernel:
 > 
 > makeoptions     DEBUG=-g
 > options         DDB, DDB_UNATTENDED

You may also want to add  DDB_TRACE.  This gets a stack
trace on console regardless of a crashdump's success.
You may have to jot it down by hand, but in many cases its enough
to characterize the panic enough for a meaningful problem report.

<...>

 > syncing bugger 3795
 > 
 > And then it hangs. Swap is 2 GB, RAM is 1 GB.
 > 


Sync'ing on panic nearly always locks my machines up too.
When I turn this off (sysctl kern.sync_on_panic=0), then
I reliably get dumps.

Is anybody able to reliably get dumps with kern.sync_on_panic enabled?
Maybe it works on SCSI boxes (all of my crashboxes are IDE)...

Drew