FCSCAN - Fibre Channel Device Scan Utility
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:fcscan
The complete usage format of the utility with its allowed options is shown below.
Usage:
:fcscan [ - n h ]
default: Show FC devices available for configuration
-n: Show only FC N-Ports
-h: Do a hardware scan and show configurable FC devices
The utility can be invoked by default without any options.
It can also be invoked with "-n" option or with "-h" option
or specifying both options together as "-nh".
Depending on the option used, the output format of the utility varies.
These are covered in detail in the following sections.
FCSCAN Default Output
The default output format of FCSCAN when invoked without any options is to print the list of FC adapter cards and devices present in the system, which can be configured in SYSGEN. The hardware path formats printed can be directly used in SYSGEN to configure the corresponding device.
:fcscan FCSCAN has found the following Fibre Channel I/O Adapter Cards and Devices on this system. SYSGEN PATH DESCRIPTION BOOT MENU PATH ============= ============= ================ 0/2/0/0 Fibre Channel Adapter 0/8/0/0 Fibre Channel Adapter 0/8/0/0.0 Fibre Channel N-Port 0/8/0/0.0.0 HP OPEN-3 disk 0/8/0/0.8.0.0.0.0.0 0/8/0/0.0.1 HP OPEN-3 disk 0/8/0/0.8.0.0.0.0.1 0/8/0/0.0.105 HP OPEN-3 disk 0/8/0/0.8.0.0.0.13.1 0/8/0/0.24 Fibre Channel N-Port 0/8/0/0.24.0 SEAGATE ST39103FC disk 0/8/0/0.8.0.255.1.8.0 0/8/0/0.25 Fibre Channel N-Port 0/8/0/0.25.0 SEAGATE ST39103FC disk 0/8/0/0.8.0.255.1.9.0 0/8/0/0.26 Fibre Channel N-Port 0/8/0/0.26.0 SEAGATE ST39103FC disk 0/8/0/0.8.0.255.1.10.0 0/8/0/0.27 Fibre Channel N-Port 0/8/0/0.27.0 SEAGATE ST39103FC disk 0/8/0/0.8.0.255.1.11.0The output from FCSCAN utility shows the following information:
- SYSGEN PATH:
- Hardware path of the FC adapter card or device. This is the path used in SYSGEN to configure the card or device in the system.
- DESCRIPTION:
- Description about whether the path specifies an FC card or device. If device, it also specifies the model and type of the device.
- BOOT MENU PATH:
- Path value for an FC device to be used in the system Boot Command Handler or firmware Main Menu to set that particular device as the primary path. The boot menu path is a detailed long format path unlike the simplified SYSGEN path. It is necessary to use this long path in boot menu because the system firmware can understand only this format to access devices. So typically to install on or boot from a FC disk, the primary path will be set to this long path for that disk as printed by FCSCAN.
:sysgen
sysgen> io
io> lp 0/8/0/0
PATH: 0/8/0/0 LDEV:
ID: A6795A TYPE: DA
PMGR: FC_DAM PMGRPRI: 6
LMGR: MAXIOS: 0
io> lp 0/8/0/0.0
PATH: 0/8/0/0.0 LDEV:
ID: FC_NPORT TYPE: DA
PMGR: FCP_NM PMGRPRI: 6
LMGR: MAXIOS: 0
io> lp 0/8/0/0.0.0
PATH: 0/8/0/0.0.0 LDEV: 60
ID: HPDARRAY TYPE: DISC
PMGR: SCSI_DISK_AND_ARRAY_DM PMGRPRI: 8
LMGR: LOGICAL_DEVICE_MANAGER MAXIOS: 0
io> lp 0/8/0/0.0.1
PATH: 0/8/0/0.0.1 LDEV: 60
ID: HPDARRAY TYPE: DISC
PMGR: SCSI_DISK_AND_ARRAY_DM PMGRPRI: 8
LMGR: LOGICAL_DEVICE_MANAGER MAXIOS: 0
io> lp 0/8/0/0.0.105
PATH: 0/8/0/0.0.105 LDEV: 60
ID: HPDARRAY TYPE: DISC
PMGR: SCSI_DISK_AND_ARRAY_DM PMGRPRI: 8
LMGR: LOGICAL_DEVICE_MANAGER MAXIOS: 0
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NOTE: For FCSCAN to be able to scan for devices under an FC card, the adapter card at this hardware path should have already been configured through SYSGEN. If the card is not configured in the system, FCSCAN will not recognize the card. If FCSCAN output shows only the adapter card but no devices under it, then it is most likely that the device has not been connected properly. Verify the FC cable connecting the FC device to the adapter. Try again running FCSCAN with "-h" option. |
FCSCAN Output with "-n" Option
The option "-n" specifies FCSCAN to print only the FC adapter cards and FC device N_Ports on the system. It does not print individual LUNs under the FC devices. This is a shorter version to easily know what FC devices are connected to each FC adapter card.
:fcscan -n FCSCAN has found the following Fibre Channel I/O Adapter Cards and N-Ports on this system. SYSGEN PATH DESCRIPTION ============= ============= 0/2/0/0 Fibre Channel Adapter 0/8/0/0 Fibre Channel Adapter 0/8/0/0.0 XP512 controller 0/8/0/0.24 SEAGATE ST39103FC disk 0/8/0/0.25 SEAGATE ST39103FC disk 0/8/0/0.26 SEAGATE ST39103FC disk 0/8/0/0.27 SEAGATE ST39103FC disk 0/8/0/0.34 HP A5236A controllerThe above output indicates that there are two FC cards in the system at hardware paths 0/2/0/0 and 0/8/0/0. There is no device connected under card 0/2/0/0. Under card 0/8/0/0, there are some FC device N_Ports available. The description column in the output specifies what kind of device each N_Port belongs to. Note that this option prints only the N_Port paths and not the paths of individual LUNs under the N_Ports. By looking at this simplified output format, the System Administrator can quickly identify what FC devices are connected to the FC cards in the system.
FCSCAN Output with "-h" Option
FCSCAN normally uses the internal I/O subsystem data structures of MPE/iX Operating System to get the list of FC cards and devices on the system. So this information reflects only what is currently known to the OS and may or may not actually match with the FC devices currently connected to the card. This is because FC physical interface allows devices to be connected while the interface is online. For example, when the system is up and running, it is possible to connect a new FC device to the system. The option "-h" specifies FCSCAN to actually perform a hardware scan of the current state of devices connected to the FC cards, before printing out the list. Using the "-h" option guarantees that the list of devices printed more accurately matches what is currently connected on the system. This option is helpful for the case where the System Administrator connects a new FC device while the system is up and wants to know the hardware path of the device for configuring it. Since the "-h" option involves an actual hardware scan of the FC devices, FCSCAN utility will take some extra time to print the output when this option is used.
:fcscan -h Scanning for Fibre Channel devices. Please wait ... FCSCAN has found the following Fibre Channel I/O Adapter Cards and Devices on this system. SYSGEN PATH DESCRIPTION BOOT MENU PATH ============= ============= ================ 0/2/0/0 Fibre Channel Adapter 0/2/0/0.95 Fibre Channel N_Port 0/2/0/0.95.1 HP A6188A disk 0/2/0/0.8.0.95.0.0.1 0/2/0/0.95.5 HP A6188A disk 0/2/0/0.8.0.95.0.0.5 0/2/0/0.95.10 HP A6188A disk 0/2/0/0.8.0.95.0.1.2 0/8/0/0 Fibre Channel Adapter 0/8/0/0.24 Fibre Channel N-Port 0/8/0/0.24.0 SEAGATE ST39103FC disk 0/8/0/0.8.0.255.1.8.0 0/8/0/0.25 Fibre Channel N-Port 0/8/0/0.25.0 SEAGATE ST39103FC disk 0/8/0/0.8.0.255.1.9.0 0/8/0/0.26 Fibre Channel N-Port 0/8/0/0.26.0 SEAGATE ST39103FC disk 0/8/0/0.8.0.255.1.10.0 0/8/0/0.27 Fibre Channel N-Port 0/8/0/0.27.0 SEAGATE ST39103FC disk 0/8/0/0.8.0.255.1.11.0The output shown above is after an actual hardware scan of the FC devices currently connected. Comparing this with the earlier default output (without any options), we can see that now a new FC device N_Port 95 is being shown under the FC card 0/2/0/0. This N_Port has three disk LUNs 1, 5 and 10 under it, referred to as HP A6188A disk. It is possible that the device was connected after the system booted up. So when FCSCAN was run with hardware scan option, it actually probed the FC devices and recognized that the new device has been connected. Thus by looking at this output, the System Administrator can get the hardware paths of LUNs under N_Port 95 and use them to configure these disks in SYSGEN. Note that now under card 0/8/0/0, the N_Port 0 is missing. It is possible that the device got disconnected. Running FCSCAN with the "-h" option helps to view the current state of the FC devices and find out which devices have been added to or removed from the system. The "-h" option is particularly useful when the System Administrator wants to connect a new FC device to a running system and configure the device online through IOCONFIG utility. After physically connecting the device to the FC adapter card, the Administrator can run FCSCAN with "-h" option, find out the hardware paths of the N_Ports/LUNs under this device and then use these hardware paths to configure them online through IOCONFIG utility. The output of FCSCAN with "-nh" option is the same as that of "-n" option, except that the list of N_Ports is printed after an actual hardware scan is performed.
FCSCAN Output in Fabric Topology
A sample output of FCSCAN utility with the FC adapter card in fabric topology is shown below:
:fcscan FCSCAN has found the following Fibre Channel I/O Adapter Cards and Devices on this system. SYSGEN PATH DESCRIPTION BOOT MENU PATH ============= ============= ================ 0/6/2/0 Fibre Channel Adapter 0/6/2/0.70383 Fibre Channel N-Port 0/6/2/0.70383.2 HP OPEN-3 disk 0/6/2/0.1.18.239.0.0.2 0/6/2/0.70383.12 HP OPEN-3 disk 0/6/2/0.1.18.239.0.1.4 0/6/2/0.70383.53 HP OPEN-3 disk 0/6/2/0.1.18.239.0.6.5In the fabric topology output printed by FCSCAN, the path component corresponding to FC N_Port represents the 24-bit N_Port ID. This path component value is usually a large number. But in the case of private loop topology the value actually represents the Loop ID and is usually a smaller value. This detail is being mentioned here just as a clarification for FCSCAN users. In spite of this, there is actually no difference in the procedure for configuring the FC N_Port or devices in SYSGEN. For both topologies, the hardware path value of the N_Port and devices as printed by FCSCAN can be used as such in SYSGEN for configuring them. This implies that irrespective of the topology currently being used, the System Administrator can simply run FCSCAN to determine the correct hardware paths and use the same for configuring in SYSGEN.
Fibre Channel Topology Changes
Whenever there is a topology change to the fibre channel standards, i.e., from private loop to public loop or fabric to private loop, the addressing method for FC devices connected will change. This is because private loop topology uses Loop ID based addressing while fabric and public loop topologies use N_port ID based addressing. Since the Loop ID or the N_Port ID is present as a component in the hardware paths for FC devices, a change in topology causes this hardware path to change. Since MPE/iX device addressing is based on hardware paths configured in SYSGEN, a change in hardware path means that the device will no longer be accessible using the original path. For this reason, it is not recommended to change the Fibre Channel topology while the system is up and running. Any changes to the fibre channel topology in order to add or delete switches/hubs should be done while the system is not running MPE/iX. After a topology change, it may be necessary to reconfigure even existing FC devices in the system because their hardware paths may have changed. It is always recommended that after a topology change, the System Administrator should run FCSCAN utility with "-h" option, find out the new hardware paths for devices and make appropriate changes in SYSGEN configuration to reflect the changes. Although online topology change is not recommended, MPE/iX does support dynamic addition or deletion of fibre channel devices within the existing topology. This is covered in detail under the section on FCSCAN output with "-h" option.
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Configuration Examples for Fibre Channel Adapters and Devices |
TDUTIL - Fibre Channel Diagnostic Utility |