HP OpenVMS systems documentation

Fibre Channel tape devices can be configured in the context of booting from the Version 7.3 CDROM distribution kit. The configuration steps are the same as the steps described in Section 7.5.4. Specifically, you must use the SYSMAN IO FIND_WWID and IO AUTOCONFIGURATION commands to configure the tape devices prior to use.

The file, SYS$DEVICES.DAT, is not created in this environment; therefore all pertinent naming information is stored in the memory data structures. Each time the CDROM is booted, you must repeat the IO FIND_WWID and IO AUTOCONFIGURE commands to name and configure the tape devices.

Note that the name of a Fibre Channel tape device in the CDROM boot environment does not persist through reboots, and may differ from the name that is assigned when booting from a read/write system disk.

7.5.12 Using an NSR or MDR With Dual FC Ports Prior to Version 7.3-1

When Fibre Channel tape support was introduced in OpenVMS Alpha Version 7.3 and Version 7.2-2, multiple paths were not supported. The information in this section pertains only to OpenVMS Alpha Version 7.3 and Version 7.2-2.

Each Fibre Channel port on an MDR supports up to eight devices (potentially more on some NSR configurations). Therefore a dual Fibre Channel port module allows support for at least 16 devices (two sets of eight devices each). To achieve proper load balancing between the two ports of a dual-port module for systems running OpenVMS Alpha Version 7.3, refer to the MDR documentation for instructions on using Selective Storage Presentation (SSP) to assign a specific device to a specific MDR port. The NSR offers similar features using custom maps, as described in the NSR documentation.

Even if multiple paths exist (because of the presence of a dual Fibre port module, or even because of multiple KGPSA adapters in the host), only the first path detected during autoconfiguration is used. Therefore, it is important to issue the SSP load-balancing commands before issuing the SYSMAN command IO AUTOCONFIGURE. Also note that, when multiple paths exist to a Fibre Channel tape device, the SYSMAN command IO FIND_WWID will continue to detect and report the presence of the device on such extraneous paths, even though IO AUTOCONFIGURE will not subsequently configure or otherwise allow access to the device on those paths.

7.5.13 Multipath Tape Support

Multipath tape support was introduced in OpenVMS Alpha Version 7.3-1. In a Fibre Channel configuration with SCSI tape devices attached to the Fibre Channel by means of an NSR (or MDR), multiple paths can exist from an Alpha host to a SCSI tape. For example, an AlphaServer host with four KGPSA adapters has four distinct paths to a tape on the Fibre Channel. Furthermore, the NSR itself can be dual ported, allowing two paths into the NSR. An AlphaServer system with four KGPSAs leading to a dual-ported NSR actually has eight different paths from the AlphaServer system to a given tape drive.

OpenVMS Alpha Version 7.3-1 (and later) configures and makes available all possible paths from an Alpha system to the SCSI tape, whereas OpenVMS Alpha Version 7.3 uses only the first path detected during autoconfiguration. You can specify a particular path with the DCL command SET DEVICE/SWITCH. Moreover, in the event of a broken connection, automatic failover takes place.

The AlphaServer console can be used to view the status of an FC interconnect. This allows you to confirm that the interconnect is set up properly before booting. If you plan to use an FC disk device for booting or dumping, you must perform some additional steps to set up those FC disk devices at the console. These topics are discussed in the next sections.

7.6.1 Viewing the FC Configuration from the Console

Console SHOW commands can be used to display information about the devices that the console detected when it last probed the system's I/O adapters. Unlike other interconnects, however, FC disk devices are not automatically included in the SHOW DEVICE output. This is because FC devices are identified by their WWIDs, and WWIDs are too large to be included in the SHOW DEVICE output. Instead, the console provides a command for managing WWIDs, named the wwidmgr command. This command enables you to display information about FC devices and to define appropriate device names for the FC devices that will be used for booting and dumping.

Note the following points about using the wwidmgr command:

• To use the wwidmgr command, if your system is an AlphaServer model 8x00, 4x00, or 1200, you must first enter diagnostic mode. On all other platforms, the wwidmgr command can be issued at any time.
• The changes made by the wwidmgr command do not take effect until after the next system initialization. After using the wwidmgr command, you must issue the initialize command.

Refer to the Wwidmgr Users' Manual for a complete description of the wwidmgr command. (The Wwidmgr Users' Manual is available in the [.DOC] directory of the Alpha Systems Firmware Update CD-ROM.)

The following examples, produced on an AlphaServer 4100 system, show some typical uses of the wwidmgr command. Other environments may require additional steps to be taken, and the output on other systems may vary slightly.

Note the following about Example 7-1:

• The wwidmgr -show wwid command displays a summary of the FC devices on the system. This command does not display information about device connectivity.
• There are two FC adapters and five disks. (All the disks are listed at the end, independent of the adapters to which they are connected.) In this example, each of the disks was assigned a device identifier at the HSG80 console. The console refers to this identifier as a user-assigned device identifier (UDID).

Example 7-1 Using wwidmgr -show wwid

P00>>>set mode diag Console is in diagnostic mode P00>>>wwidmgr -show wwid polling kgpsa0 (KGPSA-B) slot 2, bus 0 PCI, hose 1 kgpsaa0.0.0.2.1 PGA0 WWN 1000-0000-c920-a7db polling kgpsa1 (KGPSA-B) slot 3, bus 0 PCI, hose 1 kgpsab0.0.0.3.1 PGB0 WWN 1000-0000-c920-a694 [0] UDID:10 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0016 (ev:none) [1] UDID:50 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0026 (ev:none) [2] UDID:51 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0027 (ev:none) [3] UDID:60 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0021 (ev:none) [4] UDID:61 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0022 (ev:none)

Example 7-2 shows how the wwidmgr show wwid -full command displays information about FC devices and how they are connected. The display has two parts:

• The first part lists each path from an adapter to an FC port. Adapters are identified by console device names, such as KGPSAA. FC ports are identified by their WWID, such as 5000-1FE1-0000-0D14. If any FC disks are found on a path, they are listed after that path. FC disks are identified by their current console device name, followed by their WWID.
• The second part of the display lists all the FC disks and the paths through which they are reachable. In this part, which begins with [0] UDID:10... , you will see there are four paths to each disk with two paths through each adapter, KGPSAA and KGPSAB. Each path through an adapter goes to a different port on the HSG or HSV. The column titled Con indicates whether the FC disk unit is currently online to the HSG or HSV controller that this path uses.

Example 7-2 Using wwidmgr -show wwid -full

P00>>>wwidmgr -show wwid -full kgpsaa0.0.0.2.1 - Port: 1000-0000-c920-a7db kgpsaa0.0.0.2.1 - Port: 2007-0060-6900-075b kgpsaa0.0.0.2.1 - Port: 20fc-0060-6900-075b kgpsaa0.0.0.2.1 - Port: 5000-1fe1-0000-0d14 - dga12274.13.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0016 - dga15346.13.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0026 - dga31539.13.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0027 - dga31155.13.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0021 - dga30963.13.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0022 kgpsaa0.0.0.2.1 - Port: 5000-1fe1-0000-0d11 - dga12274.14.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0016 - dga15346.14.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0026 - dga31539.14.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0027 - dga31155.14.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0021 - dga30963.14.0.2.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0022 kgpsab0.0.0.3.1 - Port: 1000-0000-c920-a694 kgpsab0.0.0.3.1 - Port: 2007-0060-6900-09b8 kgpsab0.0.0.3.1 - Port: 20fc-0060-6900-09b8 kgpsab0.0.0.3.1 - Port: 5000-1fe1-0000-0d13 - dgb12274.13.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0016 - dgb15346.13.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0026 - dgb31539.13.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0027 - dgb31155.13.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0021 - dgb30963.13.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0022 kgpsab0.0.0.3.1 - Port: 5000-1fe1-0000-0d12 - dgb12274.14.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0016 - dgb15346.14.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0026 - dgb31539.14.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0027 - dgb31155.14.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0021 - dgb30963.14.0.3.1 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0022 [0] UDID:10 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0016 (ev:none) - current_unit:12274 current_col: 0 default_unit:12274 via adapter via fc_nport Con DID Lun - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d14 Yes 210013 10 - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d11 No 210213 10 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d13 Yes 210013 10 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d12 No 210213 10 [1] UDID:50 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0026 (ev:none) - current_unit:15346 current_col: 0 default_unit:15346 via adapter via fc_nport Con DID Lun - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d14 Yes 210013 50 - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d11 No 210213 50 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d13 Yes 210013 50 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d12 No 210213 50 [2] UDID:51 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0027 (ev:none) - current_unit:31539 current_col: 0 default_unit:31539 via adapter via fc_nport Con DID Lun - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d14 Yes 210013 51 - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d11 No 210213 51 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d13 Yes 210013 51 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d12 No 210213 51 [3] UDID:60 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0021 (ev:none) - current_unit:31155 current_col: 0 default_unit:31155 via adapter via fc_nport Con DID Lun - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d14 Yes 210013 60 - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d11 No 210213 60 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d13 Yes 210013 60 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d12 No 210213 60 [4] UDID:61 WWID:01000010:6000-1fe1-0000-0d10-0009-8090-0677-0022 (ev:none) - current_unit:30963 current_col: 0 default_unit:30963 via adapter via fc_nport Con DID Lun - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d14 Yes 210013 61 - kgpsaa0.0.0.2.1 5000-1fe1-0000-0d11 No 210213 61 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d13 Yes 210013 61 - kgpsab0.0.0.3.1 5000-1fe1-0000-0d12 No 210213 61

7.6.2 Setting Up FC Disks for Booting and Dumping

You must use the wwidmgr command to set up each device that you will use for booting or dumping. Once a device is set up, the console retains the information it requires to access the device in nonvolatile memory. You only have to rerun the wwidmgr command if the system configuration changes and the nonvolatile information is no longer valid.

The console provides a simplified setup command, called wwidmgr -quickset . This command can be used in either of the following cases:

• You are setting up just one device.
• All the devices you are setting up are accessed through the same ports on the HSG or HSV.

If neither description applies to your configuration, refer to the Wwidmgr Users' Manual for additional instructions.

Example 7-3 illustrates the wwidmgr -quickset command. Note the following:

• The command wwidmgr -quickset -udid 10 sets up the FC disk whose HSG or HSV device identifier is equal to 10.
• The console device names are path dependent. Each path used to access an FC disk has a different name. In this example, the wwidmgr -quickset command establishes four console device names corresponding to the four paths from the host to the FC disk:
  • dga10.1001.0.2.1
  • dga10.1002.0.2.1
  • dgb10.1003.0.3.1
  • dgb10.1004.0.3.1
• The second command, wwidmgr -quickset -udid 50 , sets up the FC disk whose HSG or HSV identifier is equal to 50.
• The changes made by the wwidmgr command do not take effect until after the next system initialization, so the next step is to issue an initialize command.
• After the initialization, the console show device command displays each FC adapter, followed by the paths through that adapter to each of the defined FC disks. The path-independent OpenVMS device name for each FC disk is displayed in the second column.

Example 7-3 Using widmgr -quickset

P00>>>wwidmgr -quickset -udid 10 Disk assignment and reachability after next initialization: 6000-1fe1-0000-0d10-0009-8090-0677-0016 via adapter: via fc nport: connected: dga10.1001.0.2.1 kgpsaa0.0.0.2.1 5000-1fe1-0000-0d14 Yes dga10.1002.0.2.1 kgpsaa0.0.0.2.1 5000-1fe1-0000-0d11 No dgb10.1003.0.3.1 kgpsab0.0.0.3.1 5000-1fe1-0000-0d13 Yes dgb10.1004.0.3.1 kgpsab0.0.0.3.1 5000-1fe1-0000-0d12 No P00>>>wwidmgr -quickset -udid 50 Disk assignment and reachability after next initialization: 6000-1fe1-0000-0d10-0009-8090-0677-0016 via adapter: via fc nport: connected: dga10.1001.0.2.1 kgpsaa0.0.0.2.1 5000-1fe1-0000-0d14 Yes dga10.1002.0.2.1 kgpsaa0.0.0.2.1 5000-1fe1-0000-0d11 No dgb10.1003.0.3.1 kgpsab0.0.0.3.1 5000-1fe1-0000-0d13 Yes dgb10.1004.0.3.1 kgpsab0.0.0.3.1 5000-1fe1-0000-0d12 No 6000-1fe1-0000-0d10-0009-8090-0677-0026 via adapter: via fc nport: connected: dga50.1001.0.2.1 kgpsaa0.0.0.2.1 5000-1fe1-0000-0d14 Yes dga50.1002.0.2.1 kgpsaa0.0.0.2.1 5000-1fe1-0000-0d11 No dgb50.1003.0.3.1 kgpsab0.0.0.3.1 5000-1fe1-0000-0d13 Yes dgb50.1004.0.3.1 kgpsab0.0.0.3.1 5000-1fe1-0000-0d12 No P00>>>initialize Initializing... P00>>>show device polling ncr0 (NCR 53C810) slot 1, bus 0 PCI, hose 1 SCSI Bus ID 7 dka500.5.0.1.1 DKA500 RRD45 1645 polling kgpsa0 (KGPSA-B) slot 2, bus 0 PCI, hose 1 kgpsaa0.0.0.2.1 PGA0 WWN 1000-0000-c920-a7db dga10.1001.0.2.1 $1$DGA10 HSG80 R024 dga50.1001.0.2.1 $1$DGA50 HSG80 R024 dga10.1002.0.2.1 $1$DGA10 HSG80 R024 dga50.1002.0.2.1 $1$DGA50 HSG80 R024 polling kgpsa1 (KGPSA-B) slot 3, bus 0 PCI, hose 1 kgpsab0.0.0.3.1 PGB0 WWN 1000-0000-c920-a694 dgb10.1003.0.3.1 $1$DGA10 HSG80 R024 dgb50.1003.0.3.1 $1$DGA50 HSG80 R024 dgb10.1004.0.3.1 $1$DGA10 HSG80 R024 dgb50.1004.0.3.1 $1$DGA50 HSG80 R024 polling isp0 (QLogic ISP1020) slot 4, bus 0 PCI, hose 1 SCSI Bus ID 15 dkb0.0.0.4.1 DKB0 RZ1CB-CS 0844 dkb100.1.0.4.1 DKB100 RZ1CB-CS 0844 polling floppy0 (FLOPPY) PCEB - XBUS hose 0 dva0.0.0.1000.0 DVA0 RX23 polling ncr1 (NCR 53C810) slot 4, bus 0 PCI, hose 0 SCSI Bus ID 7 dkc0.0.0.4.0 DKC0 RZ29B 0007 polling tulip0 (DECchip 21040-AA) slot 3, bus 0 PCI, hose 0 ewa0.0.0.3.0 00-00-F8-21-09-74 Auto-Sensing

Example 7-4 shows a boot sequence from an FC system disk. Note the following:

• The boot device is $1$DGA50 . The user has elected to enter all four paths to the device in the bootdef_dev string. This ensures that the system will be able to boot even if a path has failed.
• The first path on the boot command string, dga50.1002.0.2.1 , is not currently connected (that is, the disk is not on line to the HSG80 on that path). The console indicates this fact, retries a few times, then moves on to the next path in the bootdef_dev string. This path is currently connected, and the boot succeeds.
• After booting, the OpenVMS SHOW DEVICE command confirms that OpenVMS has configured all five of the FC devices that were displayed by the wwidmgr -show wwid command, not only the two FC disks that were set up using the console wwidmgr -quickset command. The OpenVMS SHOW DEV/MULTIPATH command confirms that OpenVMS has configured all four paths to each disk.

Example 7-4 Boot Sequence from an FC System Disk

P00>>>set bootdef_dev dga50.1002.0.2.1,dga50.1001.0.2.1,dgb50.1003.0.3.1, dgb50.1004.0.3.1 P00>>>b (boot dga50.1002.0.2.1 -flags 0,0) dga50.1002.0.2.1 is not connected dga50.1002.0.2.1 is not connected dga50.1002.0.2.1 is not connected dga50.1002.0.2.1 is not connected failed to open dga50.1002.0.2.1 (boot dga50.1001.0.2.1 -flags 0,0) block 0 of dga50.1001.0.2.1 is a valid boot block reading 919 blocks from dga50.1001.0.2.1 bootstrap code read in Building FRU table base = 200000, image_start = 0, image_bytes = 72e00 initializing HWRPB at 2000 initializing page table at 1f2000 initializing machine state setting affinity to the primary CPU jumping to bootstrap code OpenVMS (TM) Alpha Operating System, Version V7.2 ... $ SHOW DEVICE Device Device Error Volume Free Trans Mnt Name Status Count Label Blocks Count Cnt $1$DGA10: (FCNOD1) Online 0 $1$DGA50: (FCNOD1) Mounted 0 V72_SSB 4734189 303 1 $1$DGA51: (FCNOD1) Online 0 $1$DGA60: (FCNOD1) Online 0 $1$DGA61: (FCNOD1) Online 0 $ SHOW LOGICAL SYS$SYSDEVICE "SYS$SYSDEVICE" = "$1$DGA50:" (LNM$SYSTEM_TABLE) $ SHO DEV/MULTI Device Device Error Current Name Status Count Paths path $1$DGA10: (FCNOD1) Online 0 4/ 4 PGB0.5000-1FE1-0000-0D11 $1$DGA50: (FCNOD1) Mounted 0 4/ 4 PGA0.5000-1FE1-0000-0D12 $1$DGA51: (FCNOD1) Online 0 4/ 4 PGA0.5000-1FE1-0000-0D13 $1$DGA60: (FCNOD1) Online 0 4/ 4 PGB0.5000-1FE1-0000-0D14 $1$DGA61: (FCNOD1) Online 0 4/ 4 PGB0.5000-1FE1-0000-0D11 Device Device Error Current Name Status Count Paths path $1$GGA42: Online 0 4/ 4 PGB0.5000-1FE1-0000-0D11

7.7 Booting on a Fibre Channel Storage Device on OpenVMS I64 Systems

This section describes how to boot the fibre channel (FC) storage device on OpenVMS I64 systems. FC storage is supported on all storage arrays that are supported on OpenVMS systems.

OpenVMS I64 Version 8.2 supports the HP A6826A, a PCI-X dual-channel, 2-Gb Fibre Channel host-based adapter (HBA) and its variants. The A6826A HBA requires the following software and firmware:

• EFI driver Version 1.40
• RISC firmware Version 3.03.001

Fibre channel device booting supports point-to-point topology. There is no plan to support FC arbitrated loop topology.

7.7.1 Installing the Bootable Firmware

Before you can boot on a FC device on OpenVMS I64 systems, you must update the EFI bootable firmware of the flash memory of the FC HBA.

To flash the memory of the FC HBA, update the firmware of the following components:

• EFI driver firmware
• RISC firmware
• NVRAM resident in the FLASH ROM on the HBA

To update the firmware, use the efiutil.efi utility, which is located on the IPF Offline Diagnostics and Utilities CD.

To perform these firmware updates, complete the following steps:

1. Insert the IPF Offline Diagnostics and Utilities IPF 0409 5971-4257 Sept 2004 CD. You can obtain the image file in either of the following ways:
   • Order the image free of charge from the HP Software Depot site main page:

     http://www.software.hp.com

     
     Type "ipf offline" in the Search bar.

   • Download a master .iso image file and burn your own CD locally by navigating to the HP Support and Drivers website:

     http://welcome.hp.com/country/us/en/support.html

     
     Select your server product in the Support your Product bar.

2. To flash all adapters found on the system in batch mode, select the EFI Shell from the Boot Options list on the EFI Boot Manager menu.
   At the EFI console, enter the following commands (where fs0: represents the bootable partition on the CD-ROM):
   1. fs0:\efi\hp\tools\io_cards\fc2p2g\ efiutil all info
      This command provides the current EFI driver and RISC firmware version on all adapters in the system.
   2. fs0:\efi\hp\tools\io_cards\fc2p2g\ efiutil all efi_write
      This command updates the EFI driver.
   3. fs0:\efi\hp\tools\io_cards\fc2p2g\ efiutil all risc_fw_write
      This command updates the RISC firmware.
   4. fs0:\efi\hp\tools\io_cards\fc2p2g\ efiutil all nvram_write
      This command updates the NVRAM.
   5. fs0:\> reset
      This command resets the system.
3. Alternatively, you can flash each adapter separately by specifying the adapter ID and firmware file name to write to the ROM, as follows:
   1. Boot the entry that corresponds to the DVD-ROM from the Boot Options list; or specify the CD Media by selecting the "Boot Option Maintenance Menu," then selecting "Boot from a File," then selecting "Removable Media Boot."
   2. From the CD main menu, select "View I/O Cards FW Update and Configuration Utilities, and MCA Menu," then select "2Gb Fibre Channel HBA Utility." This invokes the efiutil CLI utility and displays a list of fibre channel adapters found in the system.
   3. Select the fibre channel adapter by specifying the index number. Update the EFI driver, RISC firmware driver, and the NVRAM. Repeat this step until all adapters have been updated. For example:

      efiutil.efi> adapter Adapter index number [0]? efiutil.efi> efi_write efiutil.efi> risc_fw_write efiutil.efi> nvram_write

   4. Exit the efiutil CLI by typing Quit from the utility. This will bring you to the "I/O Cards Firmware and Configuration Menu." Type q to return to the Main Menu. From the Main Menu, select X to exit and reboot the system.