Document revision date: 30 March 2001

Because SYS$SYSTEM:SYS$DEVICES.DAT is a text file, you can edit it but only to change the unit number of a Fibre Channel tape or medium changer device. However, as stated earlier, Fibre Channel tape and medium changer device information is stored internally by OpenVMS using clusterwide data structures, specifically clusterwide logical names. In OpenVMS Version 7.3, the only supported way to clean up these data structures is to do a complete cluster shutdown. A rolling reboot (leaving at least one node up during the reboot of other nodes) is inadequate to clean up the structures.

The specific steps for changing an existing device name follow:

1. Edit the SYS$SYSTEM:SYS$DEVICES.DAT file to change the unit number of the chosen device. In the basic $2$MGAnnnn or $2$GGAnnnn format, only the nnnn portion can be edited. The maximum allowed value for nnnn is 9999 and must be decimal. Be sure to choose a unit number that is not already in use by another device for that device type.
   For example, if $2$MGA26 is already associated with the WWID of another tape, then choose a unit number other than 26; if $2$GGA4 is already associated with the WWID of another medium changer, then choose a unit number other than 4.
2. If there are multiple system disks in the cluster, edit each of the SYS$DEVICES.DAT files in the same way.
3. Shut down the entire cluster to clean up existing cluster data structures.
4. Reboot the cluster. The new device names will automatically appear.

To move a tape or medium changer device without changing its name, a cluster shutdown is not required. However, you must reboot each cluster node that will access the device so that the path information is updated in the unit control blocks that represent the device.

If a device is inadvertently moved to a new path without rebooting, then subsequent attempts to mount or initialize the device, or to issue a $QIO IO$_PACKACK to it will fail with a fatal drive error.

7.5.7 Serving a Fibre Channel Tape Device

In general, all OpenVMS Alpha Version 7.3 nodes in an OpenVMS Cluster have a direct path to Fibre Channel tape devices if the nodes are connected to the same Fibre Channel fabric as the MDR. VAX nodes and Alpha nodes running earlier versions of OpenVMS, as TMSCP clients, can be served Fibre Channel tape devices by an OpenVMS Alpha Version 7.3 node. To provide this feature, pre-Version 7.3 VAX nodes require the latest update kit for TUDRIVER.EXE, and pre-Version 7.3 Alpha nodes require the latest update kit for SYS$TUDRIVER.EXE.

Medium changers, whether connected to Fibre Channel or to parallel SCSI, cannot be TMSCP served.

7.5.8 Replacing a Fibre Channel Tape Device

If one tape drive must be physically replaced by another tape drive at the same FC LUN location within the MDR, update the appropriate data structures with the IO REPLACE_WWID command.

For example, you may need to replace a defective tape drive with a new drive without rebooting the cluster, and that drive may need to retain the device name of the previous tape at that location.

The replacement device should have the same SCSI target ID as the original device. Cease all activity on the device, then type the following command to update all the necessary file and memory data structures with the WWID of the new tape drive:

$ MCR SYSMAN IO REPLACE_WWID $2$MGA1

Execute this command on each Alpha node in the cluster environment. You can accomplish this with the following commands:

$ MCR SYSMAN SYSMAN> SET ENVIRONMENT/CLUSTER SYSMAN> IO REPLACE_WWID $2$MGA1

7.5.9 Determining the Physical Location of a Fibre Channel Tape Device

Given the name of a Fibre Channel tape device, it is helpful to know how to locate the Fibre Channel tape device. To do so, follow these steps:

1. From the system manager's account, run ANALYZE/SYSTEM.
2. At the SDA prompt, type CLUE SCSI/SUMMARY.
3. Search for the name of the device (for example, MGA3) in the column labeled DEVICE.
4. Note the corresponding value in the column labeled SCSI-LUN. This SCSI LUN value is the same value used by the MDR as the FC LUN. Also note the columns labeled Port and SCSI-ID for the device; all devices associated with that same port and SCSI-ID are attached to the same physical Fibre Channel port of the same MDR.
5. At the MDR console's AMC prompt, type ShowFcScsiMap . In the column labeled FC LUN, locate the value noted in step 4. Once you find the FC LUN value, note (on the same line) the corresponding values for SCSI Bus, SCSI Target ID, and SCSI LUN. This B:T:L information describes the physical location of the device within the MDR.

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.

7.5.11 Using an MDR with Dual Fibre Ports

Currently each Fibre Channel port on an MDR supports up to eight devices. A dual Fibre Channel port module allows support for 16 devices (two sets of eight devices each). To achieve proper load balancing between the two ports of a dual-port module, refer to the MDR documentation for instructions on using Selective Storage Presentation (SSP) to assign a specific device to a specific MDR port.

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.

7.6 Using the AlphaServer Console for Configuring FC

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 User's Manual for a complete description of the wwidmgr command.

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 HSG80. The column titled Con indicates whether the FC disk unit is currently online to the HSG80 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.

If neither description applies to your configuration, refer to the Wwidmgr User's 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 HSG80 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 HSG80 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

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