What is the /dev/perf device?

[Fedon Kadifeli]

It looks like a telnet daemon is running on /dev/perf. What is the use of this device?

# ll /dev/perf
crw-rw-rw- 1 root sys 173 0x000000 Dec 30 1998 /dev/perf

# ps -ef | grep perf | grep telnet
root 23362 759 0 09:56:17 perf 0:00 telnetd

[Cheryl Griffin]

You can get information specific to the device with lssf:
# lssf /dev/perf

Is this device something that you named specifically, using mksf (make special file)?

[Bruce Laughlin]

Hi,

On my system, I don't have /dev/perf, but lsdev returns the following:# lsdev 173
Character Block Driver Class
173 -1 gelan unknown

Now, major number 173 may coorelate to a different driver on your system; the lssf command, as recommended by Cheryl Griffin should show for sure which driver you're using.

Based on the fact that on my system, major 173 appears to be related to a networking driver, and also, since you have a telnetd session running on it, I suspect that maybe this device is simply an alias to the pty/tty pseudo device files? If I were you, I'd do something like the following, and search for other devices using the 173 major number:

cd /dev
ll -R | grep 173

Hope this helps you,
Bruce Laughlin

[Fedon Kadifeli]

This device looks the same as the /dev/pts/ta device:

/dev# ll * | grep "173 0x000000"
crw-rw-rw- 1 root sys 173 0x000000 Dec 30 1998 perf
crw--w---- 1 itadmin tty 173 0x000000 Jan 10 18:23 ta

/dev# lssf perf pts/ta
pseudo driver tels minor 0x000000 perf
pseudo driver tels minor 0x000000 pts/ta

Is it safe to delete /dev/perf?

How can I find the driver name for a specific device? In this case; for the device having the major number 173?

[Dan Hetzel · Accepted solution]

Hi Fedon,

Nobody seems to know what the /dev/perf device is.
You may suppress it using 'rmsf -v /dev/perf' and check for the return value of that command with 'echo $?' (should be 0).

After that, 'insf -e' should re-install special files for all devices and pseudo-drivers.

If your /dev/perf is needed, it will be recreated.

Best regards,

Dan

[Fedon Kadifeli]

What is the difference between

rmsf /dev/xyz

and

rm /dev/xyz

?

[Dan Hetzel]

Hi Fedon,

rm is the remove that everybody knows...
rmsf removes special files and may be given flags like:
-a : Remove the definition of the device from the system along with all special files that refer to the device
-C class ..... (I won't cut and paste the whole manual page)

The list is quite long, see 'man rmsf' and you'll have everything you need to know about it :7)

Best regards,

Dan