Subject: kern/12284: vnd.c / UBC inconsistencies ?
To: None <>
From: None <>
List: netbsd-bugs
Date: 02/25/2001 21:21:42
>Number:         12284
>Category:       kern
>Synopsis:       boot-big.fs is all zeroes - changes via vnd do not show up in file immediately on system with large memory
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Feb 25 12:22:03 PST 2001
>Originator:     Frank Kardel
>Release:        current-20010224-224643
System: NetBSD pip 1.5S NetBSD 1.5S (PIP) #9: Sun Feb 25 20:05:35 MET 2001 kardel@pip:/src/NetBSD/netbsd/sys/arch/i386/compile/PIP i386
Architecture: i386
Machine: i386
	Here is what i experience:
	Since the integration of UBC the creation of floppy images (e.g. boot-big.fs) generates files with all zeroes 
	in the file. After some time the images "improve" - showing the expected data, but the INSTALL krnel still fails
	with "cannot mount root". The md memory image seems corrupted (also generated via vnd device as is boot-big.fs).
	This happens on a machine with 256Mb or more (384Mb) (everything is in memory). 

	Do a "make release" with suitable paths. Look into <RELEASEDIR>/installation/floppy and find short(!) .gz files and .fs
	files with zeroes.

	A quick glance at vnd.c revealed, that vnd.c seems to works VOP_STRATEGY() interface, while dd, cp and
	mdsetimage make use of the UBC interface. Maybe this is the area where the problem can be found/solved.