device file not created automatically

[somanaboina_522]

  Hi everybody,

     I have added a LUN to the HP-UX11iv3 server, after adding the LUN the device file not created automatically.

due to this my lvm activity got failed. is it mandatory to run the insf command after adding the LUN.??

[Torsten.]

Usually it get created when running ioscan.

It could cause problems if you present the same LUN# again.

[somanaboina_522]

Thanks Torsten,

   when the kernel finds the new hardware it should create a specaial file for the device   ..right??

then why do we need to run ioscan command ??

[chris huys_4]

Hi,

The kernel finds the new hardware once you run ioscan -fnN on hp-ux 11.31. And on 11.31 the ioscan -fnN will then do automatically the insf -e -v command to create device files for the new hardware.

So on hp-ux 11.31 this is the sequence for the new hardware to get discovered.

1. assign new hardware to the host.

2. run ioscan -fnN

# ioscan -fnN

3. check dmesg//var/adm/syslog/syslog.log to see if indeed the new hardware is found.

# dmesg

# vi /var/adm/syslog/syslog.log

Best Regards,

Chris

[Bill Hassell · Accepted solution]

>> when the kernel finds the new hardware it should create a specaial file for the device   ..right??

>> then why do we need to run ioscan command ??

The kernel never finds new hardware by itself. ioscan (without the -k option) commands each of the drivers to look for new devices. When found, each driver's response update the memory-resident kernel tables. But device files require filesystem changes, again something that the kernel does not do. Instead, insf must be used to create device files for the new hardware.

[KALABAYOV89]

insf can delete the file equipment.
After that, you can create a new file by ioscan -fnC disk

[Robert_Jewell]

> insf can delete the file equipment.
> After that, you can create a new file by ioscan -fnC disk

This is NOT correct.

rmsf is used to remove existing device files.

As Bill states above, insf is required to create (or re-create) device files.

-Bob

[Bill Hassell]

rmsf to remove...

But as I discovered, there is an undocumented feature in ioscan (at least the man pages and patch descriptions don't mention this). ioscan apparently does install new device files. This was tested on both PARISC and IA. Note that this was a casual test (one tape drive). But running insf after ioscan will always work on any version 10 and higher (assuming the driver recognizes the new hardware).