I got this panic while making a snapshot on a 1.5.1_BETA system on
the i386 platform.  I don't have softdeps enabled on the filesystem.
Does this look like a hardware issue?  I think it happened once before,
but I can't tell because of some other circumstances.  A crash dump
is available, if needed.

sd0(siop0:0:0): command timeout
siop0: scsi bus reset          
cmd 0xc0802d40 (target 0:0) in reset list
cmd 0xc0802e80 (target 0:0) in reset list
cmd 0xc0802d80 (target 0:0) in reset list
cmd 0xc0802d40 (status 2) about to be processed
cmd 0xc0802e80 (status 2) about to be processed
cmd 0xc0802d80 (status 2) about to be processed
siop0: target 0 using 16bit transfers          
siop0: target 0 now synchronous at 40.0Mhz, offset 31
Apr 23 18:14:11 host47 /netbsd: sd0(siop0:0:0): command timeout
Apr 23 18:14:13 host47 /netbsd: siop0: scsi bus reset
Apr 23 18:14:13 host47 /netbsd: cmd 0xc0802d40 (target 0:0) in reset list
dev = 0x400, ino = 292, fs = /
Apr 23 18:14:13 phost47 /netbsd: acmd 0xc0802e80 (ntarget 0:0) in rieset list
c: ifree: freeing free inode
syncing disks... panic: lockmgr: locking against myself
                                                       
dumping to dev 4,1 offset 1578047
dump 255 254 253 252 251 250 249 248 247 246 245 244 243 242 241 240 239 238 237 236 235 234 233 232 231 230 229 228 227 226 225 224 223 222 221 220 219 218 217 216 215 214 213 212 211 210 209 208 207 206 205 204 203 202 201 200 199 198 197 196 195 194 193 192 191 190 189 188 187 186 185 184 183 182 181 180 179 178 177 176 175 174 173 172 171 170 169 168 167 166 165 164 163 162 161 160 159 158 157 156 155 154 153 152 151 150 149 148 147 146 145 144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105 104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 succeeded
 
rebooting...
            
>> NetBSD/i386 BIOS Boot, Revision 2.7
>> (riz@cesium.corp.equinix.com, Thu Aug 31 09:00:41 PDT 2000)
>> Memory: 636/261120 k
Use hd1a:netbsd to boot sd0 when wd0 is also installed
Press return to boot now, any other key for boot menu
booting wd0a:netbsd - starting in 0 
2053411+247180+176088 [65+140848+115645]=0x29c69c
Copyright (c) 1996, 1997, 1998, 1999, 2000
    The NetBSD Foundation, Inc.  All rights reserved.
Copyright (c) 1982, 1986, 1989, 1991, 1993           
    The Regents of the University of California.  All rights reserved.
                                                                      
NetBSD 1.5.1_BETA (TOOYOU) #3: Mon Apr 23 16:42:10 PDT 2001
    root@host47.lab.equinix.com:/usr/src/sys/arch/i386/compile/TOOYOU
cpu0: Intel Pentium III (E) (686-class), 601.41 MHz                  
total memory = 255 MB                              
avail memory = 234 MB
using 3297 buffers containing 13188 KB of memory
BIOS32 rev. 0 found at 0xfdb50                  
mainbus0 (root)               
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled       
pchb0 at pci0 dev 0 function 0       
pchb0: Intel product 0x71a0 (rev. 0x00)
ppb0 at pci0 dev 1 function 0: Intel product 0x71a1 (rev. 0x00)
pci1 at ppb0 bus 1                                             
pci1: i/o space, memory space enabled
pcib0 at pci0 dev 7 function 0       
pcib0: Intel 82371AB PCI-to-ISA Bridge (PIIX4) (rev. 0x02)
pciide0 at pci0 dev 7 function 1: Intel 82371AB IDE controller (PIIX4) (rev. 0x01)
pciide0: bus-master DMA support present
pciide0: primary channel wired to compatibility mode
atapibus0 at pciide0 channel 0                      
cd0 at atapibus0 drive 0: <CD-540E, , 1.0A> type 5 cdrom removable
cd0: 32-bit data port                                             
cd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 2
pciide0: primary channel interrupting at irq 14             
cd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 2 (using DMA data transfers)
pciide0: secondary channel wired to compatibility mode                         
pciide0: disabling secondary channel (no drives)      
Intel 82371AB USB Host Controller (PIIX4) (USB serial bus, revision 0x01) at pci0 dev 7 function 2 not configured
Intel 82371AB Power Management Controller (PIIX4) (miscellaneous bridge, revision 0x02) at pci0 dev 7 function 3 not configured
siop0 at pci0 dev 11 function 0: Symbios Logic 53c896 (ultra2-wide scsi)
siop0: using on-board RAM                                               
siop0: interrupting at irq 9
scsibus0 at siop0: 16 targets, 8 luns per target
siop1 at pci0 dev 11 function 1: Symbios Logic 53c896 (ultra2-wide scsi)
siop1: using on-board RAM                                               
siop1: interrupting at irq 10
scsibus1 at siop1: 16 targets, 8 luns per target
Ensoniq AudioPCI 97 (audio multimedia, revision 0x08) at pci0 dev 12 function 0 not configured
fxp0 at pci0 dev 13 function 0: Intel i82557 Ethernet, rev 8
fxp0: interrupting at irq 11                                
fxp0: Ethernet address 00:e0:81:10:bf:ae, 10/100 Mb/s
inphy0 at fxp0 phy 1: i82555 10/100 media interface, rev. 4
inphy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
vga0 at pci0 dev 14 function 0: ATI Technologies Mach64 GV (rev. 0x3a)
wsdisplay0 at vga0                                                    
isa0 at pcib0     
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com0: console                                              
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
pckbc0 at isa0 port 0x60-0x64                              
lm0 at isa0 port 0x290-0x297: W83782D
npx0 at isa0 port 0xf0-0xff: using exception 16
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2      
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
apm0 at mainbus0: Power Management spec V1.2       
biomask f7e7 netmask ffe7 ttymask ffe7      
scsibus0: waiting 2 seconds for devices to settle...
siop0: target 0 using tagged queuing                
sd0 at scsibus0 target 0 lun 0: <SEAGATE, ST318436LW, 0005> SCSI3 0/direct fixed
siop0: target 0 using 16bit transfers                                          
siop0: target 0 now synchronous at 40.0Mhz, offset 31
sd0: 17522 MB, 14384 cyl, 6 head, 415 sec, 512 bytes/sect x 35885168 sectors
scsibus1: waiting 2 seconds for devices to settle...                        
boot device: sd0                                    
root on sd0a dumps on sd0b
root file system type: ffs
swapctl: adding /dev/sd0b as swap device at priority 0
Automatic boot in progress: starting file system checks.
/dev/rsd0a: UNREF FILE  I=14500  OWNER=root MODE=100644
/dev/rsd0a: SIZE=0 MTIME=Apr 24 01:13 2001  (CLEARED)
/dev/rsd0a: FREE BLK COUNT(S) WRONG IN SUPERBLK (SALVAGED)
/dev/rsd0a: SUMMARY INFORMATION BAD (SALVAGED)
/dev/rsd0a: BLK(S) MISSING IN BIT MAPS (SALVAGED)
/dev/rsd0a: BLK(S) MISSING IN BIT MAPS (SALVAGED)
/dev/rsd0a: 10291 files, 305552 used, 223930 free (3266 frags, 27583 blocks, 0.6% fragmentation)
/dev/rsd0a: MARKING FILE SYSTEM CLEAN
/dev/rsd0e: INCORRECT BLOCK COUNT I=1970337 (592 should be 208) (CORRECTED)
8071912 DUP I=1970349
/dev/rsd0e: UNEXPECTED INCONSISTENCY; RUN fsck_ffs MANUALLY.
THE FOLLOWING FILE SYSTEM HAD AN UNEXPECTED INCONSISTENCY:
        ffs: /dev/rsd0e (/usr)
Automatic file system check failed; help!
Apr 24 01:17:47 init: /bin/sh on /etc/rc terminated abnormally, going to single user mode
Enter pathname of shell or RETURN for sh: 
# cat /etc/fstab
/dev/sd0a / ffs rw 1 1
/dev/sd0b none swap sw 0 0
/dev/sd0e /usr ffs rw 1 2
/kern /kern kernfs rw
# 


Thanks,
+j

-- 
Jeff Rizzo                                         http://boogers.sf.ca.us/~riz