topic Re: HP-UX command ioscan in Operating System - HP-UX

HP-UX command ioscan

STL — Fri, 04 Nov 2005 04:37:04 GMT

When i create a new virtual disk on SAN and present this to my system, the istance number associate is the progressive number and not the free istance number.
Where HP-UX save the ouput of the command IOSCAN? Where i see the istance number?

Re: HP-UX command ioscan

Joseph Loo — Fri, 04 Nov 2005 04:39:18 GMT

hi,

r u referring to the column I from the ioscan output:

# ioscan -fnC disk

regards.

Re: HP-UX command ioscan

Muthukumar_5 — Fri, 04 Nov 2005 04:40:19 GMT

ioscan -fn will give instance number in second column.

-Muthu

Re: HP-UX command ioscan

Warren_9 — Fri, 04 Nov 2005 04:43:22 GMT

hi,

There is no ioscan output saved on HP-UX.

The hardware structure is in the kernel and you could use the "-k" option to list the kernel tree.

# ioscan -fnkC disk

GOOD LUCK!!

Re: HP-UX command ioscan

Arunvijai_4 — Fri, 04 Nov 2005 04:54:07 GMT

Instance number is assigned by OS (kernel) and its not advisable to modify. You can use #ioscan -fnCdisk

-Arun

Re: HP-UX command ioscan

melvyn burnard — Fri, 04 Nov 2005 05:31:03 GMT

HP-UX does not save any output from the ioscan command. All this does is allow you to see what hardware there is attached to the system, whether there is a driver attached (CLAIMED), hardware gone missing after boot time (NO_HW) etc.
I believe what you are asking is:
How does HP-UX remember what instance number is assigned to what device?

If so, this is done using the /etc/ioconfig file which is NOT an ascii file in association with the ioinit command (run from /etc/inittab).
When the system boots, it scans the I/O tree, and compares what it finds with the contents of this file. If a new device is found, it assigns the next instance number to the device and records it in the ioconfig file.

man ioconfig
man ioinit

Re: HP-UX command ioscan

Bharat Katkar — Fri, 04 Nov 2005 08:49:41 GMT

Hi,
I think Monaco's question is why does OS does not assign the free Instance no instead of just assigning next instance no to the newly added device.

for e.g.

i have devices with instance no 1,2,3,4 and 5.
Then i removed one device with instance no. 3 so now i have devices with instance n0. 1,2,4 and 5.

Now in this case if you add new device OS should assign 3 but it assigns 6. So why OS is not assigning 3 to the new device?

Monaco correct me if i am wrong.

Now if that is the question what i have seen is the same thing, OS keeps on incrementing the instance no and doesn't look back what all instance no are free from alloted pool.

Don't know the specific reason for the same.

Regards,

Re: HP-UX command ioscan

Bill Hassell — Fri, 04 Nov 2005 09:13:24 GMT

I believe that insf (which creates device files for new hardware) does a simple table scan (developed from the ioconfig file) looking for the next higher number. You can remove the current device file(s) for a particular hardware device (rmsf -H) then use the instance option to run insf -H to reinstall the device file(s). Note that rmsf (for unknown reasons) will sometimes fail to remove the device files. You can't just rm the files because rmsf also modifies the ioconfig file. The instance number is only a record-keeping number and having incremental numbers is only cosmetic.