Hi all, Without a doubt I can reproduce this panic every single time. 1. Insert UMASS USB Stick 2. mount as msdos 3. umount USB stick 4. remove USB stick 4. some time laster [hours/days] *panic*: panic: vinvalbuf: dirty bufs OS-Version: FreeBSD 5.4-STABLE #0: Thu Jul 14 12:32:30 CST 2005 [/var/log/messages before panic'd. Interestingly it takes a few hours or days before the panic actually occurs]. Sep 9 17:03:11 hostname kernel: umass0: at uhub1 port 1 (addr 2) disconnected Sep 9 17:03:11 hostname kernel: (da0:umass-sim0:0:0:0): lost device Sep 9 17:03:11 hostname kernel: (da0:umass-sim0:0:0:0): removing device entry Sep 9 17:03:11 hostname kernel: umass0: detached Sep 12 08:15:21 hostname kernel: panic: vinvalbuf: dirty bufs Sep 12 08:15:21 hostname kernel: KDB: enter: panic Sep 12 08:15:21 hostname kernel: Dumping 767 MB backrace: (kgdb) bt #0 doadump () at pcpu.h:160 #1 0xc0469db5 in db_fncall (dummy1=0, dummy2=0, dummy3=7919, dummy4=0xde1619f4 "\200\237\226?") at /usr/src/sys/ddb/db_command.c:531 #2 0xc0469b64 in db_command (last_cmdp=0xc0969684, cmd_table=0x0, aux_cmd_tablep=0xc08ea080, aux_cmd_tablep_end=0xc08ea09c) at /usr/src/sys/ddb/db_command.c:349 #3 0xc0469c55 in db_command_loop () at /usr/src/sys/ddb/db_command.c:455 #4 0xc046bb0d in db_trap (type=3, code=0) at /usr/src/sys/ddb/db_main.c:221 #5 0xc0686dd3 in kdb_trap (type=0, code=0, tf=0xde161b40) at /usr/src/sys/kern/subr_kdb.c:470 #6 0xc0860273 in trap (frame {tf_fs = -1064566760, tf_es = 16, tf_ds = -568983536, tf_edi = 1, tf_esi = -1064505670, tf_ebp = -568976504, tf_isp = -568976532, tf_ebx = -568976448, tf_edx = 0, tf_ecx = -1056878592, tf_eax = 18, tf_trapno = 3, tf_err = 0, tf_eip = -1066898615, tf_cs = 8, tf_eflags = 646, tf_esp = -1064519392, tf_ss = -1064525103}) at /usr/src/sys/i386/i386/trap.c:584 #7 0xc084dfaa in calltrap () at /usr/src/sys/i386/i386/exception.s:140 #8 0xc08c0018 in ?? () #9 0x00000010 in ?? () #10 0xde160010 in ?? () #11 0x00000001 in ?? () #12 0xc08ceeba in ?? () #13 0xde161b88 in ?? () #14 0xde161b6c in ?? () #15 0xde161bc0 in ?? () #16 0x00000000 in ?? () #17 0xc1015000 in ?? () #18 0x00000012 in ?? () #19 0x00000003 in ?? () #20 0x00000000 in ?? () #21 0xc0686b49 in kdb_enter (msg=0x0) at cpufunc.h:56 #22 0xc066c309 in panic (fmt=0xc08ceeba "vinvalbuf: dirty bufs") at /usr/src/sys/kern/kern_shutdown.c:550 #23 0xc06cbbfe in vinvalbuf (vp=0xc4a2d318, flags=1, cred=0x0, td=0x0, slpflag=0, slptimeo=0) at /usr/src/sys/kern/vfs_subr.c:972 #24 0xc06cf4b1 in vclean (vp=0xc4a2d318, flags=8, td=0xc1f0f480) at /usr/src/sys/kern/vfs_subr.c:2478 #25 0xc06cfcb6 in vgonel (vp=0xc4a2d318, td=0x0) at /usr/src/sys/kern/vfs_subr.c:2697 #26 0xc06ca94f in vlrureclaim (mp=0xc2107000) at pcpu.h:157 #27 0xc06cac7b in vnlru_proc () at /usr/src/sys/kern/vfs_subr.c:598 #28 0xc065325e in fork_exit (callout=0xc06caa29 <vnlru_proc>, arg=0x0, frame=0x0) at /usr/src/sys/kern/kern_fork.c:791 #29 0xc084e00c in fork_trampoline () at /usr/src/sys/i386/i386/exception.s:209 (kgdb) USB Code in kernel: # USB support device uhci # UHCI PCI->USB interface device ohci # OHCI PCI->USB interface device usb # USB Bus (required) USB Controllers: uhci0: <Intel 82801BA/BAM (ICH2) USB controller USB-A> port 0xa400-0xa41f irq 19 at device 31.2 on pci0 usb0: <Intel 82801BA/BAM (ICH2) USB controller USB-A> on uhci0 usb0: USB revision 1.0 uhci1: <Intel 82801BA/BAM (ICH2) USB controller USB-B> port 0xa000-0xa01f irq 23 at device 31.4 on pci0 usb1: <Intel 82801BA/BAM (ICH2) USB controller USB-B> on uhci1 usb1: USB revision 1.0 Offending USB UMASS Stick: Sep 9 15:46:46 hostname kernel: umass0: USB Flash Disk, rev 2.00/2.00, addr 2 Sep 9 15:46:47 hostname kernel: da0 at umass-sim0 bus 0 target 0 lun 0 Sep 9 15:46:47 hostname kernel: da0: <JetFlash TS1GJF2B 2.00> Removable Direct Access SCSI-2 device Sep 9 15:46:47 hostname kernel: da0: 1.000MB/s transfers Sep 9 15:46:47 hostname kernel: da0: 1000MB (2048000 512 byte sectors: 64H 32S/T 1000C) - aW