>Number:         20296
>Category:       kern
>Synopsis:       vnd device locks up under high write load and large images
>Confidential:   no
>Severity:       critical
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Feb 11 10:24:00 PST 2003
>Closed-Date:
>Last-Modified:
>Originator:     Wojciech Puchar
>Release:        release-1-5 (at most 1 week old)
>Organization:
TENSOR ap
>Environment:
NetBSD chylonia.3miasto.net 1.5.4_ALPHA NetBSD 1.5.4_ALPHA (local) #8: Thu Jan 16 19:44:35 CET 2003     wojtek@chylonia.3miasto.net:/home/wojtek/kernel/local i386

>Description:
copying lots of small files (pkgsrc) from normal ffs filesystem to vnd-mounted ffs filesystem (3GB image)
locks up whole system.

"lock up" means that it responds to everything except any disk access. all disk access just waits.
only reset helps
>How-To-Repeat:
dd if=/dev/zero of=image bs=1024k count=3000
disklabel -I -i vnd0
at least type W amd Q
newfs -m 5 -i 16384 -b 8192 -f 1024 -c 96 /dev/rvnd0a (that's what i used)
mount -o async,noatime /dev/vnd0a /mnt

and

cp -R /usr/src/pkgsrc /mnt

will quickly render system unusable

>Fix:
without async it works fine, while slow
softdep not tested


>Release-Note:
>Audit-Trail:
>Unformatted: