7.3 Hardware Management Databases


7.3 Hardware Management Databases

IMPORTANT

Many of the ASCII formatted files we are about to discuss will very likely be converted to binary files in a future release of Tru64 UNIX, so we highly recommend not becoming dependent on the fact that these files are currently ASCII.

Given the hardware changes that have occurred with the V5.0 release of Tru64 UNIX, several databases are used to keep track of the configuration information. Note that these files must not be edited manually. There are programs (see hwmgr and dsfmgr(8) below) that can be used to modify some of these databases while others are modified by kernel subsystems. Note that all of the following files are located in the /etc directory.

  • dccd.dat

The dccd.dat file is the Category to Class-Directory, Prefix Database used by dsfmgr to create device special files. This is an ASCII file but should not be modified. The following information is contained in the file:

  • The device category.

  • The device name.

  • The device type (block, character, rewind, norewind, sgeneric, storage, *).

  • The subdirectory where the device special file is to be located.

  • The device special file type (block or character).

  • The file mode permission bits (in octal).

  • The device prefix.

  • The instance width (e.g., a cdrom device will always have at least one digit in the instance field: cdrom0).

Note that the kevm device instance width is zero and has a device name of only kevm, and a hardwired terminal with an instance width of two would be named tty00.

 # more /etc/dccd.dat    disk        cdrom       block            disk              b 600 cdrom       1    disk        cdrom       char             rdisk             c 600 cdrom       1 ...    pseudo      kevm        *                .                 c 600 kevm      0 ...    terminal    hardwired   *                .                 c 666 tty       2 ... 

  • dcdd.dat

The dcdd.dat file is the Device Class Directory Default Database. It is used by the dsfmgr command to create the device directories. This is an ASCII file and should not be modified. The file contains the directory location (local - /dev, or cluster - /devices), the directory mode permission bits (in octal), and the directory name.

 # cat /etc/dcdd.dat   l 0755 .   l 0755 none   c 0755 cport   c 0755 disk   c 0755 rdisk   c 0755 tape   c 0755 ntape   c 0755 changer   c 0755 dmapi 
  • ddr.db

The Dynamic Device Recognition (DDR) database is used to describe SCSI CAM (common access method) device parameters and characteristics so that devices can be dynamically created. This is a data file and is created by ddr_config(8) using the ddr.dbase(4) file as input. See the ddr.dbase(4) reference page for more information.

  • dec_devsw_db

    This refers to the primary device switch table database file. It contains the device driver major numbers and device switch entries. This is a binary data file and is maintained by the kernel but can be viewed using the devswmgr(8) program.

  • dec_hw_db

    This binary file holds the hardware topology for the system. Contained within this file is the hardware persistence information for buses and controllers. The file is maintained by the kernel driver framework and can be modified and queried by the hwmgr command using the "name" subsystem. For example:

 # hwmgr -show name  HWID:     NAME      HOSTNAME       PERSIST TYPE       PERSIST AT  --------------------------------------------------------------------------------    33:     ata0      sheridan       BUS                pci0 slot 13    49:     isp0      sheridan       BUS                pci0 slot 15    44:     itpsa1    sheridan       BUS                pci0 slot 14    36:     itpsa0    sheridan       BUS                pci0 slot 15    51:     mchan0    sheridan       CONTROLLER         pci0 slot 16     5:     pci0      sheridan       BUS                nexus    50:     scsi3     sheridan       CONTROLLER         isp0 slot 0    37:     scsi2     sheridan       CONTROLLER         itpsa0 slot 0    35:     scsi1     sheridan       CONTROLLER         ata0 slot 1    34:     scsi0     sheridan       CONTROLLER         ata0 slot 0    32:     tu1       sheridan       CONTROLLER         pci0 slot 11    31:     tu0       sheridan       CONTROLLER         pci0 slot 9 

  • dec_hwc_cdb and dec_hwc_ldb

These are the hardware component database files. The "ldb" file is the local (or member-specific) database file for this system, while the "cdb" file is the common (or cluster-wide) database file. These databases contain information for all the registered hardware components for the system.

The "cdb" file contains storage devices and some of their information, like the WWID. This can be verified by typing the following command: "strings/etc/dec_hwc_cdb".

The "ldb" file contains information for the other hardware components (adapters, cpu, keyboard, mouse, etc.) as well as some storage device information (user_name, phys_location, etc.). Component information can be seen in the following example:

 # hwmgr -show component  HWID:  HOSTNAME    FLAGS     SERVICE      COMPONENT NAME  ---------------------------------------------------------     1:  sheridan    -----     none         COMPAQ AlphaStation XP900 466 MHz     2:  sheridan    r----     none         CPU0     3:  sheridan    r-d--     none         scp     4:  sheridan    r-d--     none         kevm     5:  sheridan    r----     none         pci0 ...     53: sheridan    -cds-     iomap        SCSI-WWID:0c000008:0000-0e11-0019-9fbe     54: sheridan    -cds-     iomap        SCSI-WWID:0c000008:0000-0e11-0019-9492     55: sheridan    -cds-     iomap        SCSI-WWID:0c000008:0000-0e11-0018-ba75     56: sheridan    -cds-     iomap        SCSI-WWID:0c000008:0000-0e11-0018-9f1f     57: sheridan    -cd--     iomap        SCSI-WWID:0c000008:0000-0e11-0018-9f33     58: sheridan    -cd--     iomap        SCSI-WWID:0c000008:0000-0e11-0018-9f1a 

  • dec_scsi_db

This file is owned by the SCSI/CAM subsystem and is used to store the WWIDs and track the SCSI devices that are known to the system. This binary data file is also used by the hwmgr command. For example:

 # hwmgr –show scsi        SCSI                    DEVICE   DEVICE     DRIVER   NUM    DEVICE    FIRST  HWID: DEVICEID   HOSTNAME     TYPE     SUBTYPE    OWNER    PATH   FILE      VALID PATH -----------------------------------------------------------------------------------     0: 0          sheridan     cdrom    none       0        1      (null)    40: 1          sheridan     disk     none       2        1      dsk0      [2/0/0]    41: 2          sheridan     disk     none       2        1      dsk1      [2/1/0]    45: 3          sheridan     cdrom    none       0        1      cdrom0    [0/0/0]    53: 4          sheridan     disk     none       0        1      dsk2      [3/0/0]    54: 5          sheridan     disk     none       0        1      dsk3      [3/1/0]    55: 6          sheridan     disk     none       0        1      dsk4      [3/2/0]    56: 7          sheridan     disk     none       0        1      dsk5      [3/3/0]    57: 8          sheridan     disk     none       0        1      dsk6      [3/4/0]    58: 9          sheridan     disk     none       0        1      dsk7      [3/5/0] 

  • dec_unid_db

This database contains unique IDs. According to the Tru64 UNIX System Administration guide, "This is a binary database that stores the preceding highest hardware identifier (HWID) assigned to a hardware component. This database is used to generate the next HWID to be assigned to a newly-installed hardware component." There is other information contained in the file, as shown by the output from using the strings(1) command, which indicates that the file is used for unique IDs other than just the HWID, although that may be its most common function.

 # strings /etc/dec_unid_db DEC_UNID hardware dsf_group_id cluster_minor control_port_id 
  • dfsc.dat and dfsl.dat

The device file status data files are ASCII files that are maintained by the dsfmgr command. The dfsl.dat file is for both local (or member-specific) device special files status and the old device special files names. The dfsc.dat file contains the common (or cluster-wide) device special files status. The files are split into three sections:

  1. Instance

    The instance record contains three fields:

    • Type

    • Base Name

    • Instance

    For instance (excuse the pun):

     "I: dsk 8" 
  2. Version

    This record looks like a comment, but it contains the version of the file format as well as the hostname and O/S version.

     "# 1.0 sheridan V5.1 (Rev. 732) Tue Mar 20 01:23:34 2001" 
  3. Status

    The status record currently contains 12 fields:

    Status (A, C, or d)

    Device Path

    Device Node ID

    Cluster Dev Major/Minor #

    Device Instance

    Old Node Name

    Basename ID

    Local Dev Major/Minor #

    Device Prefix

    Device Type

    Hardware ID

    Device Suffix

    (block or character)

Here are a few examples:

The first example is from /etc/dfsc.dat and shows the "A" (active) status for a cluster device.

 A:        0        1300041      45    10   0   b  ""        /dev/disk/ cdrom 0 a 

The second example is also from /etc/dfsc.dat and shows the "d" (deactivated) status for a cluster device.

 d:        0        1300043      45    10   1   b  ""        /dev/disk/ cdrom 0 b 

The last example shows two entries from /etc/dfsl.dat illustrating the "C" (cluster) status for a local device.

 C:   5500000   1300001      30     6     0    b    fd0a     ~ "" "" "" C:   5500000   1300002      30     6     0    c    rfd0a    ~ "" "" "" 

  • gen_databases

This file contains the list of hardware databases, the files used by them, and (optionally) the database handler. This is an ASCII text file but should not be modified.




TruCluster Server Handbook
TruCluster Server Handbook (HP Technologies)
ISBN: 1555582591
EAN: 2147483647
Year: 2005
Pages: 273

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