Managing Devices in the Oracle Solaris OS

The following sections provide overview information about features that manage devices in the Oracle Solaris OS. For information about accessing devices, see Accessing Devices.

Identifying Device Support

You can use the device detection tool to identify whether your x86 hardware is supported in this Oracle Solaris release. For more information, go to the following site:

http://www.oracle.com/webfolder/technetwork/hcl/hcts/device_detect.jsp

About Device Drivers

A computer typically uses a wide range of peripheral devices and mass-storage devices. Your system, for example, probably has a disk drive, a keyboard and a mouse, and some kind of magnetic backup medium. Other commonly used devices include the following:

• DVD drives

• Printers and plotters

• Light pens

• Touch-sensitive screens

• Digitizers

• Tablet-and-stylus pairs

The Oracle Solaris software does not directly communicate with all these devices. Each type of device requires different data formats, protocols, and transmission rates.

A device driver is a low-level program that allows the operating system to communicate with a specific piece of hardware. The driver serves as the operating system's “interpreter” for that piece of hardware.

How to Customize a Driver Configuration

In the Oracle Solaris 11 release, driver customizations are made in the /etc/driver/drv directory rather than in the /kernel directory as in previous releases. This improvement means that your driver customizations are not overwritten when the system is upgraded. The files in the /etc/driver/drv directory are preserved during the upgrade.

Customizing a driver configuration usually means that a per-device parameter or global property that impacts all devices is added or modified.

1. Become an administrator.
2. Copy the original vendor supplied driver.conf file to the /etc/driver/drv directory. For example:

   # cp /kernel/drv/sd.conf /etc/driver/drv/sd.conf

3. Modify the parameter entry and save the file.

   For example, the sd.conf includes the following entry for sd device at target 0, lun 0:

   name="sd" class="scsi" target=0 lun=0;

   To add the retries parameter for this device, modify the existing entry as follows:

   name="sd" class="scsi" target=0 lun=0 retries=4;

4. Display the customized property value. For example:

   # prtconf -u
   sd, instance #1
              Admin properties:
                  name='retries' type=int items=1
                      value=00000004

Automatic Configuration of Devices

The kernel consists of a small generic core with a platform-specific component and a set of modules. The kernel is configured automatically in the Oracle Solaris release.

A kernel module is a hardware or software component that is used to perform a specific task on the system. An example of a loadable kernel module is a device driver that is loaded when the device is accessed.

The platform-independent kernel is /kernel/genunix. The platform-specific component is /platform/`uname -m`/kernel/unix.

The kernel modules are described in the following table.

Table 5-2 Description of Solaris Kernel Modules

The system determines what devices are attached to it at boot time. Then, the kernel configures itself dynamically, loading needed modules into memory. At this time, device drivers are loaded when devices, such as disk devices and tape devices, are accessed. This process is called autoconfiguration because all kernel modules are loaded automatically when they are needed.

You can customize the way in which kernel modules are loaded by modifying the /etc/system file. For instructions on modifying this file, see system(4).

Features and Benefits of Autoconfiguration

The benefits of autoconfiguration are as follows:

• Main memory is used more efficiently because modules are loaded when needed.

• There is no need to reconfigure the kernel when new devices are added to the system.

• Drivers can be loaded and tested without having to rebuild the kernel and reboot the system.

Autoconfiguration is used when you add a new device (and driver) to the system. In previous releases, it was necessary to perform a reconfiguration boot if you added a device to a system that is shutdown. Device configuration enhancements make a reconfiguration boot unnecessary when a device is added to a system that is shutdown.

You can add, remove, or replace devices in the Oracle Solaris OS while the system is still running, if the system components support hot-plugging. For information about hot-plugging devices, see Chapter 6, Dynamically Configuring Devices (Tasks).

What You Need for Unsupported Devices

Device drivers needed to support a wide range of standard devices are included in the Oracle Solaris release. These drivers can be found in the /kernel/drv and /platform/`uname -m`/kernel/drv directories.

However, if you have purchased an unsupported device, the manufacturer should provide the software that is needed for the device to be properly installed, maintained, and administered.

At a minimum, this software includes a device driver and its associated configuration (.conf) file. The .conf files reside in the drv directories. This software might also include custom maintenance and administrative utilities because the device might be incompatible with Oracle Solaris utilities.

For more information about what you need for unsupported devices, contact your device manufacturer.

Displaying Device Configuration Information

Three commands are used to display system and device configuration information.

For information on the device names that are used to identify devices on the system, see Device Naming Conventions.

driver not attached Message

The following driver-related message might be displayed by the prtconf and sysdef commands:

device, instance #number (driver not attached)

This message does not always mean that a driver is unavailable for this device. This message means that no driver is currently attached to the device instance because no device exists at this node or the device is not in use. Drivers are loaded automatically when the device is accessed. They are unloaded when the device is not in use.

In-Use Device Error Checking

The following utilities detect when a specified device is in use:

• dumpadm

• format

• mkfs and newfs

• swap

These enhancements mean that the above utilities might detect some of the following usage scenarios:

• Device is part of a ZFS storage pool

• Device is a dump or swap device

• Mounted file system or an entry for the device exists in the /etc/vfstab file

For example, if you attempt to use the format utility to access an active device, you will see a message similar to the following:

# format
Searching for disks...done
AVAILABLE DISK SELECTIONS:
       0. c1t0d0 <FUJITSU-MAY2073RCSUN72G-0401 cyl 8921 alt 2 hd 255 sec 63>
          /pci@0,0/pci1022,7450@2/pci1000,3060@3/sd@0,0
          /dev/chassis/SYS/HD0/disk
       1. c1t1d0 <FUJITSU-MAY2073RCSUN72G-0401-68.37GB>
          /pci@0,0/pci1022,7450@2/pci1000,3060@3/sd@1,0
          /dev/chassis/SYS/HD1/disk
Specify disk (enter its number): 0
selecting c1t0d0
[disk formatted]
/dev/dsk/c1t0d0s0 is part of active ZFS pool rpool. Please see zpool(1M).


FORMAT MENU:
.
.
.

How to Display System Configuration Information

Use the output of the prtconf and sysdef commands to identify which disk, tape, and DVD devices are connected to the system. The output of these commands displays the driver not attached messages next to the device instances. Because these devices are always being monitored by some system process, the driver not attached message is usually a good indication that no device exists at that device instance.

Use the sysdef command to display system configuration information that include pseudo devices, loadable modules, and selected kernel parameters.

• Display system and device configuration information.

  • Display all the devices connected to a system.

    For example, the following prtconf -v output on a SPARC system identifies the disk devices connected to the system. The detailed disk information is described in the Device Minor Nodes section.

    $ /usr/sbin/prtconf -v | more
    Memory size: 32640 Megabytes
    System Peripherals (Software Nodes):
    
    SUNW,SPARC-Enterprise-T5220
    .
    .
    .
    location: /dev/chassis/SUN-Storage-J4400.0918QAKA24/SCSI_Device__2/disk
    Device Minor Nodes:
         dev=(27,40)
            dev_path=/pci@0/pci@0/pci@8/pci@0/pci@a/LSILogic,sas@0/sd@2,0:a
                spectype=blk type=minor
                dev_link=/dev/dsk/c4t2d0s0
            dev_path=/pci@0/pci@0/pci@8/pci@0/pci@a/LSILogic,sas@0/sd@2,0:a,raw
                spectype=chr type=minor
                dev_link=/dev/rdsk/c4t2d0s0
                Device Minor Layered Under:
                mod=zfs accesstype=blk
                    dev_path=/pseudo/zfs@0
                Minor properties:
                    name='Nblocks' type=int64 items=1 dev=(27,40)
                          value=0000000074702c8f
                    name='Size' type=int64 items=1 dev=(27,40)
                    value=000000e8e0591e00
    .
    .
    .

  • Display information about one specific device connected to the system.

    For example, the following prtconf output on a SPARC system displays the sd instance number for /dev/dsk/c4t2d0s0.

    # prtconf -v /dev/dsk/c4t2d0s0 | grep instance
    sd, instance #5

  • Display only the devices that are attached to the system.

    # prtconf | grep -v not

  • Display device usage information.

    For example, the following fuser command displays which processes are accessing the /dev/console device.

    # fuser -d /dev/console
    /dev/console:     5742o    2269o   20322o     858o

Example 5-1 Displaying System Configuration Information

The following prtconf output is displayed on an x86 based system.

# prtconf
System Configuration:  Oracle Corporation  i86pc
Memory size: 8192 Megabytes
System Peripherals (Software Nodes):

i86pc
    scsi_vhci, instance #0
    pci, instance #0
        pci108e,4843, instance #0
        pci8086,25e2, instance #0
            pci8086,3500, instance #7
                pci8086,3510, instance #9
                pci8086,3518, instance #10
                    pci108e,4843, instance #0
                    pci108e,4843, instance #1
            pci8086,350c, instance #8
        pci8086,25e3 (driver not attached)
        pci8086,25f8, instance #2
            pci108e,286, instance #0
                disk, instance #0
                disk, instance #2
                disk, instance #3
                disk, instance #1
        pci8086,25e5 (driver not attached)
        pci8086,25f9 (driver not attached)
        pci8086,25e7 (driver not attached)
        pci108e,4843, instance #0 (driver not attached)
        pci108e,4843, instance #1
        pci108e,4843, instance #2 (driver not attached)
        pci108e,4843 (driver not attached)
        pci108e,4843 (driver not attached)
        pci108e,4843 (driver not attached)
        pci108e,4843 (driver not attached)
        pci8086,2690, instance #6
            pci108e,125e, instance #2
            pci108e,125e, instance #3
        pci108e,4843, instance #0
        pci108e,4843, instance #1
            device, instance #0
                keyboard, instance #0
                mouse, instance #1
        pci108e,4843, instance #2
        pci108e,4843, instance #3
        pci108e,4843, instance #0
            storage, instance #0
                disk, instance #4
.
.
.

The following sysdef output is displayed from an x86 based system.

# sysdef
* Hostid
*
  29f10b4d
*
* i86pc Configuration
*
*
* Devices
*
+boot (driver not attached)
memory (driver not attached)
aliases (driver not attached)
chosen (driver not attached)
i86pc-memory (driver not attached)
i86pc-mmu (driver not attached)
openprom (driver not attached)
options, instance #0
packages (driver not attached)
delayed-writes (driver not attached)
itu-props (driver not attached)
isa, instance #0
    motherboard (driver not attached)
    pnpADP,1542, instance #0
    asy, instance #0
    asy, instance #1
    lp, instance #0 (driver not attached)
    fdc, instance #0
        fd, instance #0
        fd, instance #1 (driver not attached)
    kd (driver not attached)
    kdmouse (driver not attached)
.
.
.

Resolving Faulty Devices

A device retirement mechanism isolates a device as faulty by the fault management framework (FMA). This feature allows faulty devices to be safely and automatically inactivated to avoid data loss, data corruption, or panics and system down time. The retirement process is done safely, taking into account the stability of the system after the device has been retired.

Critical devices are never retired. If you need to manually replace a retired device, use the fmadm repair command after the device replacement so that system knows that the device is replaced, in addition to the manual replacement steps.

For more information, see fmadm(1M).

A general message regarding device retirement is displayed on the console and written to the /var/adm/messages file so that you aware of a retired device. For example:

Aug 9 18:14 starbug genunix: [ID 751201 kern.notice] NOTICE: One or more I/O devices have been retired

You can use the prtconf command to identify specific retired devices. For example:

# prtconf
.
.
.
pci, instance #2
        scsi, instance #0
            disk (driver not attached)
            tape (driver not attached)
            sd, instance #3
            sd, instance #0 (retired)
        scsi, instance #1 (retired)
            disk (retired)
            tape (retired)
    pci, instance #3
        network, instance #2 (driver not attached)
        network, instance #3 (driver not attached)
    os-io (driver not attached)
    iscsi, instance #0
    pseudo, instance #0 
.
.
.

How to Resolve a Faulty Device

Use the steps below to resolve a faulty device or a device that has been retired.

You can also review ZFS device problem or failure information by using the zpool status or the fmdump command. For ZFS device problem or failure information, see Chapter 11, Oracle Solaris ZFS Troubleshooting and Pool Recovery, in Oracle Solaris Administration: ZFS File Systems.

1. Identify the faulted device with the fmadm faulty command.

   # fmadm faulty
   --------------- ------------------------------------  -------------- ---------
   TIME            EVENT-ID                              MSG-ID         SEVERITY
   --------------- ------------------------------------  -------------- ---------
   May 06 03:38:06 0376b4b6-fce7-c0f0-ffd9-a0a685376284  ZFS-8000-D3    Major     
   
   Host        : neo-2
   Platform    : Sun-Fire-X4140    Chassis_id  : 0904QAD02C
   Product_sn  : 
   
   Fault class : fault.fs.zfs.device
   Affects     : zfs://pool=tank/vdev=c26c72a8ffcff889
                     faulted and taken out of service
   Problem in  : zfs://pool=tank/vdev=c26c72a8ffcff889
                     faulted and taken out of service
   
   Description : A ZFS device failed.  Refer to http://sun.com/msg/ZFS-8000-D3 for
                 more information.
   
   Response    : No automated response will occur.
   
   Impact      : Fault tolerance of the pool may be compromised.
   
   Action      : Run 'zpool status -x' and replace the bad device.

2. Replace the faulty or retired device or clear the device error.

   After a faulty device is replaced in a ZFS storage pool, clear the device error. For example:

   # zpool clear rpool c4t0d0s0

   If an intermittent device error occurred but the device was not replaced, you can attempt to clear the error as shown above.

3. Clear the FMA fault.

   # fmadm repair 0376b4b6-fce7-c0f0-ffd9-a0a685376284

4. Confirm that the fault is cleared.

   # fmadm faulty