dev === :: NAME dev - device data SYNOPSIS dev [-i | -p | -d | -D ] [-V | -v index [file]] DESCRIPTION If no argument is entered, this command dumps character and block device data. -i display I/O port usage; on 2.4 kernels, also display I/O memory usage. -p display PCI device data. -d display disk I/O statistics: TOTAL: total number of allocated in-progress I/O requests SYNC: I/O requests that are synchronous ASYNC: I/O requests that are asynchronous READ: I/O requests that are reads (older kernels) WRITE: I/O requests that are writes (older kernels) DRV: I/O requests that are in-flight in the device driver. If the device driver uses blk-mq interface, this field shows N/A(MQ). If not available, this column is not shown. -D same as -d, but filter out disks with no in-progress I/O requests. If the dumpfile contains device dumps: -V display an indexed list of all device dumps present in the vmcore, showing their file offset, size and name. -v index select and display one device dump based upon an index value shown by the -V option, shown in a default human-readable format; alternatively, the "rd -f" option along with its various format options may be used to further tailor the output. file only used with -v, copy the device dump data to a file. EXAMPLES Display character and block device data: crash> dev CHRDEV NAME CDEV OPERATIONS 1 mem f79b83c0 memory_fops 4 /dev/vc/0 c07bc560 console_fops 4 tty f7af5004 tty_fops 4 ttyS f7b02204 tty_fops 5 /dev/tty c07bc440 tty_fops 5 /dev/console c07bc4a0 console_fops 5 /dev/ptmx c07bc500 ptmx_fops 6 lp c5797e40 lp_fops 7 vcs f7b03d40 vcs_fops 10 misc f7f68640 misc_fops 13 input f79b8840 input_fops 21 sg f7f12840 sg_fops 29 fb f7f8c640 fb_fops 128 ptm f7b02604 tty_fops 136 pts f7b02404 tty_fops 162 raw c0693e40 raw_fops 180 usb f79b8bc0 usb_fops 189 usb_device c06a0300 usbfs_device_file_operations 216 rfcomm f5961a04 tty_fops 254 pcmcia f79b82c0 ds_fops BLKDEV NAME GENDISK OPERATIONS 1 ramdisk f7b23480 rd_bd_op 8 sd f7cab280 sd_fops 9 md f7829b80 md_fops 11 sr f75c24c0 sr_bdops 65 sd (none) 66 sd (none) 67 sd (none) 68 sd (none) 69 sd (none) 70 sd (none) 71 sd (none) 128 sd (none) 129 sd (none) 130 sd (none) 131 sd (none) 132 sd (none) 133 sd (none) 134 sd (none) 135 sd (none) 253 device-mapper c57a0ac0 dm_blk_dops 254 mdp (none) Display PCI data: crash> dev -p PCI_DEV BU:SL.FN CLASS: VENDOR-DEVICE c00051c0 00:00.0 Host bridge: Intel 440BX - 82443BX Host c0005250 00:01.0 PCI bridge: Intel 440BX - 82443BX AGP c00052e0 00:07.0 ISA bridge: Intel 82371AB PIIX4 ISA c0005370 00:07.1 IDE interface: Intel 82371AB PIIX4 IDE c0005400 00:07.2 USB Controller: Intel 82371AB PIIX4 USB c0005490 00:07.3 Bridge: Intel 82371AB PIIX4 ACPI c0005520 00:11.0 Ethernet controller: 3Com 3C905B 100bTX c00055b0 00:13.0 PCI bridge: DEC DC21152 c0005640 01:00.0 VGA compatible controller: NVidia [PCI_DEVICE 28] c00056d0 02:0a.0 SCSI storage controller: Adaptec AIC-7890/1 c0005760 02:0e.0 SCSI storage controller: Adaptec AIC-7880U Display I/O port and I/O memory usage: crash> dev -i RESOURCE RANGE NAME c03036d4 0000-ffff PCI IO c0302594 0000-001f dma1 c03025b0 0020-003f pic1 c03025cc 0040-005f timer c03025e8 0060-006f keyboard c0302604 0080-008f dma page reg c0302620 00a0-00bf pic2 c030263c 00c0-00df dma2 c0302658 00f0-00ff fpu c122ff20 0170-0177 ide1 c122f240 0213-0213 isapnp read c122ff40 02f8-02ff serial(auto) c122ff00 0376-0376 ide1 c03186e8 03c0-03df vga+ c122ff60 03f8-03ff serial(auto) c123851c 0800-083f Intel Corporation 82371AB PIIX4 ACPI c1238538 0840-085f Intel Corporation 82371AB PIIX4 ACPI c122f220 0a79-0a79 isapnp write c122f200 0cf8-0cff PCI conf1 c1238858 dc00-dc7f 3Com Corporation 3c905B 100BaseTX [Cyclone] c122fc00 dc00-dc7f 00:11.0 c12380c8 dce0-dcff Intel Corporation 82371AB PIIX4 USB c1238d1c e000-efff PCI Bus #02 c1237858 e800-e8ff Adaptec AIC-7880U c1237458 ec00-ecff Adaptec AHA-2940U2/W / 7890 c1239cc8 ffa0-ffaf Intel Corporation 82371AB PIIX4 IDE RESOURCE RANGE NAME c03036f0 00000000-ffffffff PCI mem c0004000 00000000-0009ffff System RAM c03026ac 000a0000-000bffff Video RAM area c03026fc 000c0000-000c7fff Video ROM c0302718 000c9800-000cdfff Extension ROM c0302734 000ce000-000ce7ff Extension ROM c0302750 000ce800-000cffff Extension ROM c03026e0 000f0000-000fffff System ROM c0004040 00100000-07ffdfff System RAM c0302674 00100000-0028682b Kernel code c0302690 0028682c-0031c63f Kernel data c0004060 07ffe000-07ffffff reserved c1239058 ec000000-efffffff Intel Corporation 440BX/ZX - 82443BX/ZX Host bridge c1238d54 f1000000-f1ffffff PCI Bus #02 c1239554 f2000000-f5ffffff PCI Bus #01 c1237074 f4000000-f5ffffff nVidia Corporation Riva TnT2 [NV5] c1238d38 fa000000-fbffffff PCI Bus #02 c1237874 faffe000-faffefff Adaptec AIC-7880U c127ec40 faffe000-faffefff aic7xxx c1237474 fafff000-faffffff Adaptec AHA-2940U2/W / 7890 c127eec0 fafff000-faffffff aic7xxx c1239538 fc000000-fdffffff PCI Bus #01 c1237058 fc000000-fcffffff nVidia Corporation Riva TnT2 [NV5] c1238874 fe000000-fe00007f 3Com Corporation 3c905B 100BaseTX [Cyclone] c0004080 fec00000-fec0ffff reserved c00040a0 fee00000-fee0ffff reserved c00040c0 ffe00000-ffffffff reserved Display disk I/O statistics: crash> dev -d MAJOR GENDISK NAME REQUEST_QUEUE TOTAL READ WRITE DRV 2 ffff81012d8a5000 fd0 ffff81012dc053c0 12 0 12 0 22 ffff81012dc6b000 hdc ffff81012d8ae340 2 2 0 0 8 ffff81012dd71000 sda ffff81012d8af040 6 0 6 6 8 ffff81012dc77000 sdb ffff81012d8b5740 0 0 0 0 8 ffff81012d8d0c00 sdc ffff81012d8ae9c0 0 0 0 0 Display the available device dumps: crash> dev -V INDEX OFFSET SIZE NAME 0 0x240 33558464 cxgb4_0000:02:00.4 1 0x2001240 33558464 cxgb4_0000:03:00.4 Extract a specified device dump to file: crash> dev -v 0 device_dump_0.bin DEVICE: cxgb4_0000:02:00.4 33558464 bytes copied from 0x240 to device_dump_0.bin Format and display a device's dump data to the screen using the "rd" command: crash> rd -f 0x240 -32 8 240: 040b69e2 00000038 000e0001 00675fd4 .i..8........_g. 250: 00000000 21600047 00000000 00000000 ....G.`!........ Display a device's dump data to the screen using the default format: crash> dev -v 1 DEVICE: cxgb4_0000:03:00.4 2001240: 00000038040b69e2 00af985c000e0001 .i..8.......\... 2001250: 2150004700000000 0000000000000000 ....G.P!........ 2001260: 0000000000000000 0000000000000000 ................ 2001270: 0000000000000000 0002fccc00000001 ................ 2001280: 00000000000027b0 0000000000000000 .'.............. ...