How to get hard disk serial number using Python

Forge picture Forge · Nov 16, 2010 · Viewed 29.2k times · Source

How can I get the serial number of a hard disk drive using Python on Linux?

I would like to use a Python module to do that instead of running an external program such as hdparm. Perhaps using the fcntl module?

Answer

fmark picture fmark · Nov 16, 2010

Linux

As you suggested, fcntl is the way to do this on Linux. The C code you want to translate looks like this:

static struct hd_driveid hd;
int fd;

if ((fd = open("/dev/hda", O_RDONLY | O_NONBLOCK)) < 0) {
    printf("ERROR opening /dev/hda\n");
    exit(1);
}

if (!ioctl(fd, HDIO_GET_IDENTITY, &hd)) {
    printf("%.20s\n", hd.serial_no);
} else if (errno == -ENOMSG) {
    printf("No serial number available\n");
} else {
    perror("ERROR: HDIO_GET_IDENTITY");
    exit(1);
}

Translated into Python on Ubuntu 9.10, it goes a little something like this:

import sys, os, fcntl, struct

if os.geteuid() >  0:
    print("ERROR: Must be root to use")
    sys.exit(1)

with open(sys.argv[1], "rb") as fd:
    # tediously derived from the monster struct defined in <hdreg.h>
    # see comment at end of file to verify
    hd_driveid_format_str = "@ 10H 20s 3H 8s 40s 2B H 2B H 4B 6H 2B I 36H I Q 152H"
    # Also from <hdreg.h>
    HDIO_GET_IDENTITY = 0x030d
    # How big a buffer do we need?
    sizeof_hd_driveid = struct.calcsize(hd_driveid_format_str)

    # ensure our format string is the correct size
    # 512 is extracted using sizeof(struct hd_id) in the c code
    assert sizeof_hd_driveid == 512 

    # Call native function
    buf = fcntl.ioctl(fd, HDIO_GET_IDENTITY, " " * sizeof_hd_driveid)
    fields = struct.unpack(hd_driveid_format_str, buf)
    serial_no = fields[10].strip()
    model = fields[15].strip()
    print("Hard Disk Model: %s" % model)
    print("  Serial Number: %s" % serial_no)


## For documentation purposes, this is the struct copied from <hdreg.h>
# struct hd_driveid {
#   unsigned short  config;     /* lots of obsolete bit flags */
#   unsigned short  cyls;       /* Obsolete, "physical" cyls */
#   unsigned short  reserved2;  /* reserved (word 2) */
#   unsigned short  heads;      /* Obsolete, "physical" heads */
#   unsigned short  track_bytes;    /* unformatted bytes per track */
#   unsigned short  sector_bytes;   /* unformatted bytes per sector */
#   unsigned short  sectors;    /* Obsolete, "physical" sectors per track */
#   unsigned short  vendor0;    /* vendor unique */
#   unsigned short  vendor1;    /* vendor unique */
#   unsigned short  vendor2;    /* Retired vendor unique */
#   unsigned char   serial_no[20];  /* 0 = not_specified */
#   unsigned short  buf_type;   /* Retired */
#   unsigned short  buf_size;   /* Retired, 512 byte increments
#                    * 0 = not_specified
#                    */
#   unsigned short  ecc_bytes;  /* for r/w long cmds; 0 = not_specified */
#   unsigned char   fw_rev[8];  /* 0 = not_specified */
#   unsigned char   model[40];  /* 0 = not_specified */
#   unsigned char   max_multsect;   /* 0=not_implemented */
#   unsigned char   vendor3;    /* vendor unique */
#   unsigned short  dword_io;   /* 0=not_implemented; 1=implemented */
#   unsigned char   vendor4;    /* vendor unique */
#   unsigned char   capability; /* (upper byte of word 49)
#                    *  3:  IORDYsup
#                    *  2:  IORDYsw
#                    *  1:  LBA
#                    *  0:  DMA
#                    */
#   unsigned short  reserved50; /* reserved (word 50) */
#   unsigned char   vendor5;    /* Obsolete, vendor unique */
#   unsigned char   tPIO;       /* Obsolete, 0=slow, 1=medium, 2=fast */
#   unsigned char   vendor6;    /* Obsolete, vendor unique */
#   unsigned char   tDMA;       /* Obsolete, 0=slow, 1=medium, 2=fast */
#   unsigned short  field_valid;    /* (word 53)
#                    *  2:  ultra_ok    word  88
#                    *  1:  eide_ok     words 64-70
#                    *  0:  cur_ok      words 54-58
#                    */
#   unsigned short  cur_cyls;   /* Obsolete, logical cylinders */
#   unsigned short  cur_heads;  /* Obsolete, l heads */
#   unsigned short  cur_sectors;    /* Obsolete, l sectors per track */
#   unsigned short  cur_capacity0;  /* Obsolete, l total sectors on drive */
#   unsigned short  cur_capacity1;  /* Obsolete, (2 words, misaligned int)     */
#   unsigned char   multsect;   /* current multiple sector count */
#   unsigned char   multsect_valid; /* when (bit0==1) multsect is ok */
#   unsigned int    lba_capacity;   /* Obsolete, total number of sectors */
#   unsigned short  dma_1word;  /* Obsolete, single-word dma info */
#   unsigned short  dma_mword;  /* multiple-word dma info */
#   unsigned short  eide_pio_modes; /* bits 0:mode3 1:mode4 */
#   unsigned short  eide_dma_min;   /* min mword dma cycle time (ns) */
#   unsigned short  eide_dma_time;  /* recommended mword dma cycle time (ns) */
#   unsigned short  eide_pio;       /* min cycle time (ns), no IORDY  */
#   unsigned short  eide_pio_iordy; /* min cycle time (ns), with IORDY */
#   unsigned short  words69_70[2];  /* reserved words 69-70
#                    * future command overlap and queuing
#                    */
#   unsigned short  words71_74[4];  /* reserved words 71-74
#                    * for IDENTIFY PACKET DEVICE command
#                    */
#   unsigned short  queue_depth;    /* (word 75)
#                    * 15:5 reserved
#                    *  4:0 Maximum queue depth -1
#                    */
#   unsigned short  words76_79[4];  /* reserved words 76-79 */
#   unsigned short  major_rev_num;  /* (word 80) */
#   unsigned short  minor_rev_num;  /* (word 81) */
#   unsigned short  command_set_1;  /* (word 82) supported
#                    * 15:  Obsolete
#                    * 14:  NOP command
#                    * 13:  READ_BUFFER
#                    * 12:  WRITE_BUFFER
#                    * 11:  Obsolete
#                    * 10:  Host Protected Area
#                    *  9:  DEVICE Reset
#                    *  8:  SERVICE Interrupt
#                    *  7:  Release Interrupt
#                    *  6:  look-ahead
#                    *  5:  write cache
#                    *  4:  PACKET Command
#                    *  3:  Power Management Feature Set
#                    *  2:  Removable Feature Set
#                    *  1:  Security Feature Set
#                    *  0:  SMART Feature Set
#                    */
#   unsigned short  command_set_2;  /* (word 83)
#                    * 15:  Shall be ZERO
#                    * 14:  Shall be ONE
#                    * 13:  FLUSH CACHE EXT
#                    * 12:  FLUSH CACHE
#                    * 11:  Device Configuration Overlay
#                    * 10:  48-bit Address Feature Set
#                    *  9:  Automatic Acoustic Management
#                    *  8:  SET MAX security
#                    *  7:  reserved 1407DT PARTIES
#                    *  6:  SetF sub-command Power-Up
#                    *  5:  Power-Up in Standby Feature Set
#                    *  4:  Removable Media Notification
#                    *  3:  APM Feature Set
#                    *  2:  CFA Feature Set
#                    *  1:  READ/WRITE DMA QUEUED
#                    *  0:  Download MicroCode
#                    */
#   unsigned short  cfsse;      /* (word 84)
#                    * cmd set-feature supported extensions
#                    * 15:  Shall be ZERO
#                    * 14:  Shall be ONE
#                    * 13:6 reserved
#                    *  5:  General Purpose Logging
#                    *  4:  Streaming Feature Set
#                    *  3:  Media Card Pass Through
#                    *  2:  Media Serial Number Valid
#                    *  1:  SMART selt-test supported
#                    *  0:  SMART error logging
#                    */
#   unsigned short  cfs_enable_1;   /* (word 85)
#                    * command set-feature enabled
#                    * 15:  Obsolete
#                    * 14:  NOP command
#                    * 13:  READ_BUFFER
#                    * 12:  WRITE_BUFFER
#                    * 11:  Obsolete
#                    * 10:  Host Protected Area
#                    *  9:  DEVICE Reset
#                    *  8:  SERVICE Interrupt
#                    *  7:  Release Interrupt
#                    *  6:  look-ahead
#                    *  5:  write cache
#                    *  4:  PACKET Command
#                    *  3:  Power Management Feature Set
#                    *  2:  Removable Feature Set
#                    *  1:  Security Feature Set
#                    *  0:  SMART Feature Set
#                    */
#   unsigned short  cfs_enable_2;   /* (word 86)
#                    * command set-feature enabled
#                    * 15:  Shall be ZERO
#                    * 14:  Shall be ONE
#                    * 13:  FLUSH CACHE EXT
#                    * 12:  FLUSH CACHE
#                    * 11:  Device Configuration Overlay
#                    * 10:  48-bit Address Feature Set
#                    *  9:  Automatic Acoustic Management
#                    *  8:  SET MAX security
#                    *  7:  reserved 1407DT PARTIES
#                    *  6:  SetF sub-command Power-Up
#                    *  5:  Power-Up in Standby Feature Set
#                    *  4:  Removable Media Notification
#                    *  3:  APM Feature Set
#                    *  2:  CFA Feature Set
#                    *  1:  READ/WRITE DMA QUEUED
#                    *  0:  Download MicroCode
#                    */
#   unsigned short  csf_default;    /* (word 87)
#                    * command set-feature default
#                    * 15:  Shall be ZERO
#                    * 14:  Shall be ONE
#                    * 13:6 reserved
#                    *  5:  General Purpose Logging enabled
#                    *  4:  Valid CONFIGURE STREAM executed
#                    *  3:  Media Card Pass Through enabled
#                    *  2:  Media Serial Number Valid
#                    *  1:  SMART selt-test supported
#                    *  0:  SMART error logging
#                    */
#   unsigned short  dma_ultra;  /* (word 88) */
#   unsigned short  trseuc;     /* time required for security erase */
#   unsigned short  trsEuc;     /* time required for enhanced erase */
#   unsigned short  CurAPMvalues;   /* current APM values */
#   unsigned short  mprc;       /* master password revision code */
#   unsigned short  hw_config;  /* hardware config (word 93)
#                    * 15:  Shall be ZERO
#                    * 14:  Shall be ONE
#                    * 13:
#                    * 12:
#                    * 11:
#                    * 10:
#                    *  9:
#                    *  8:
#                    *  7:
#                    *  6:
#                    *  5:
#                    *  4:
#                    *  3:
#                    *  2:
#                    *  1:
#                    *  0:  Shall be ONE
#                    */
#   unsigned short  acoustic;   /* (word 94)
#                    * 15:8 Vendor's recommended value
#                    *  7:0 current value
#                    */
#   unsigned short  msrqs;      /* min stream request size */
#   unsigned short  sxfert;     /* stream transfer time */
#   unsigned short  sal;        /* stream access latency */
#   unsigned int    spg;        /* stream performance granularity */
#   unsigned long long lba_capacity_2;/* 48-bit total number of sectors */
#   unsigned short  words104_125[22];/* reserved words 104-125 */
#   unsigned short  last_lun;   /* (word 126) */
#   unsigned short  word127;    /* (word 127) Feature Set
#                    * Removable Media Notification
#                    * 15:2 reserved
#                    *  1:0 00 = not supported
#                    *  01 = supported
#                    *  10 = reserved
#                    *  11 = reserved
#                    */
#   unsigned short  dlf;        /* (word 128)
#                    * device lock function
#                    * 15:9 reserved
#                    *  8   security level 1:max 0:high
#                    *  7:6 reserved
#                    *  5   enhanced erase
#                    *  4   expire
#                    *  3   frozen
#                    *  2   locked
#                    *  1   en/disabled
#                    *  0   capability
#                    */
#   unsigned short  csfo;       /*  (word 129)
#                    * current set features options
#                    * 15:4 reserved
#                    *  3:  auto reassign
#                    *  2:  reverting
#                    *  1:  read-look-ahead
#                    *  0:  write cache
#                    */
#   unsigned short  words130_155[26];/* reserved vendor words 130-155 */
#   unsigned short  word156;    /* reserved vendor word 156 */
#   unsigned short  words157_159[3];/* reserved vendor words 157-159 */
#   unsigned short  cfa_power;  /* (word 160) CFA Power Mode
#                    * 15 word 160 supported
#                    * 14 reserved
#                    * 13
#                    * 12
#                    * 11:0
#                    */
#   unsigned short  words161_175[15];/* Reserved for CFA */
#   unsigned short  words176_205[30];/* Current Media Serial Number */
#   unsigned short  words206_254[49];/* reserved words 206-254 */
#   unsigned short  integrity_word; /* (word 255)
#                    * 15:8 Checksum
#                    *  7:0 Signature
#                    */
# };

Apologies for the length, I thought it useful to include the original C struct as a comment. Also, I'm pretty new to both the fcntl and struct modules, so I may be doing something unidomatic. In anycase, run from the command-line (with root privelidges) it looks like this (I've redacted my exact serial for privacy):

fmark@fmark-laptop:~/Desktop/hdserial$ sudo python hd.py "/dev/sda"
Hard Disk Model: FUJITSU MHV2080BH PL
  Serial Number: NW--------

What's going on here?

In order to be able to understand what is going on here, you need to look at the #include <linux/hdreg.h> in the original C program. This include imports the HDIO_GET_IDENTITY constant and the struct hd_driveid. I've copied the struct as a comment into the python sourcecode above, so I won't repeat it here. To find out what is going on with HDIO_GET_IDENTITY, grep the source-code for it (on Ubuntu this is at /usr/include/linux/hdreg.h. You should find something like this:

 #define HDIO_GET_IDENTITY       0x030d  /* get IDE identification info */

Thus, you find that HDIO_GET_IDENTITY is just a constant that tells fcntl that you are interested in getting HD info. As you will notice, that same value (0x030d is an integer in hexadecimal notation) is assigned to a variable in the python code.

Windows

I realise now you are interested in Linux, but I'll keep this here for posterity. The following will get the HDD serial number on Windows (you will need to install the wmi package):

import wmi
c = wmi.WMI()
for item in c.Win32_PhysicalMedia():
    print item