Guidelines for OpenVMS Cluster Configurations


Previous Contents Index

7.5.5 Changing the Name of an Existing Fibre Channel Tape Device

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. To clean up these data structures, you must 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 32767 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.

7.5.6 Moving a Physical Tape Device on Fibre Channel

When you move a tape or medium changer device without changing its name, rebooting is not required. However, you must ensure that the NSR or MDR has assigned a FC LUN to the device at its new location, and you must then run SYSMAN IO AUTOCONFIGURE to configure the new physical path to the device. For changers only, you must also manually switch the changer to the new path using the SET DEVICE/SWITCH/PATH=new_path command. The previous paths will still show up in the SHOW DEV/FULL display, but those paths will be stale and unused, with no harmful side effects; after the next reboot the stale paths will disappear.

7.5.7 Swapping Out an NSR on Fibre Channel

You can swap out an NSR without rebooting the Alpha system or Integrity server system.

After attaching the new NSR, use the Mapping submenu in the Visual Manager to populate the Indexed map on each Fibre Channel port of the NSR and reboot the NSR. An alternative way to map the new NSR is to copy the .cfg file from the previous NSR via the NSR's FTP utility.

Once the Indexed map is populated, run SYSMAN IO AUTOCONFIGURE to configure the new physical paths to the tape. For changers only, you must also manually switch the changer to the new path using the SET DEVICE/SWITCH/PATH=new_path command. The previous paths will still show up in the SHOW DEV/FULL display, but those paths will be stale and unused, with no harmful side effects; after the next reboot the stale paths will disappear.

7.5.8 Serving a Fibre Channel Tape Device

In general, all OpenVMS Alpha or Integrity server 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 NSR or MDR.

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

7.5.9 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 or NSR, 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 

In some cases, this command may fail because the device name $2$MGA1 no longer exists in the SHOW DEVICE display. This happens when the system has been rebooted some time after the drive has malfunctioned. In such a case, you must specify both the device name and the WWID, as shown in the following example.

The WWID must be the WWID of the new device that resides at the same Port/Target/LUN location as the replaced device. (To determine the value of the WWID that resides at a particular Port/Target/LUN location, use the SYSMAN IO LIST_WWID command.)


$ MCR SYSMAN 
SYSMAN> SET ENVIRONMENT/CLUSTER 
SYSMAN> IO REPLACE_WWID $2$MGA1/WWID=02000008:500E-09E0-0009-4E44

Note

This command should not be used to rename devices or redefine WWID correlations. The specified WWID must not be associated with any other device name in the cluster.

7.5.10 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 or NSR 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 or NSR.
  5. For the NSR, enter the Mapping submenu of the Visual Manager and click on Edit/View next to the Select Map box to display the Indexed Map for the current port.
    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 NSR. Additional device information is available by clicking on 'Report' in the main menu of the Visual Manager.
    If an MDR is being used, at the MDR console's AMC prompt, similar information is available by typing ShowFcScsiMap .

7.5.11 Accessing a Fibre Channel Tape Device in a Standalone Environment

Fibre Channel tape devices can be configured in the context of booting from the 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 Multipath Tape Support

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 or an Integrity server system 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 systems configure and makes available all possible paths from an Alpha or an Integrity server system to the SCSI tape. 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.

Note

Multipath failover between direct and MSCP-served paths is not supported for tape devices (unlike multipath failover between direct and MSCP-served paths for SCSI and Fibre Channel disks.)

However, there is support for TMSCP clients of multipath sets, in which all members of the serving multipath set must be directly connected to the Fibre Channel. If one member of the set fails, another member will provide the local path to the device for use by the client.

7.6 Using the AlphaServer Console for Configuring FC (Alpha Only)

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:

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:

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:

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:

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:

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:

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 


Previous Next Contents Index