High Frequency Noise Caused by Moving the Mouse

recently, I have experience very weird problem.
old computer(but it works fine) has make high frequency noise whenever I move the mouse.
I could not stand. and I start to find it.

many post tell about it. "oh! it's grounding problem. check your electricity!"
but, my house has perfect grounding already.

and then, someone tell about it. "oh, it's problem of power options on the mainboard. disable the power saving mode!"
but, it's not works properly.

finally, I thought that it's problem of mouse own self.
so, I had check the mouse options. and figured out it.
the suspect is mouse's "Polling-Rate".

Polling-Rate is the rate of checking mouse pointer location.
if your mouse has high Pollin-Rate, you can get more precise pointing.
but it has very high frequency(over 500hz), and makes unpleasant noise forward to speaker.

(This is logitech mouse G-Hub utility. watch yellow box.)

so I have down Polling-Rate from 1000hz to 125hz and DPI from 1600 to 800.

of course high DPI is not main suspect, but I feel that very high DPI help high frequency noise.

so if you has suffer from high frequency noise from mouse, change the Polling-Rate options or get the mouse that has low Polling-Rate.

SMB, FTP, FSTAB configuration example

hello.

it is just some configuration file for backup.
never mind it.

FSTAB example
SMB example
VSFTPD example

iPadOS weird SMB share permission error

Hello! good day!


today, I have upgrade my iPad to 'iPadOS 13'.
I had wondered if File-App works SMB share feature properly.
I have small NAS using Raspberry-Pi that attached USB memory sticks. so I tested.

first, connection was just good. but, problem is after.
iPad reject to read and write file. just file browsing allowd.
but my Macbook and Windows notebook were no problem to read and write file.

it's so weird situation.
so I thought that NAS has problem.
I tried to find cause. and figured out something strange.

MacOS and Windows are writing file on SMB share as root qualification. and also my USB sticks as formatted exFAT are mounted as root:root ownership and 777 permission.
I suspected that this is the point to solve the problem.

and I tried to change the folder and files ownership and permission, but I could not give them ownership and permission properly. exactly, I tried to change ownership from root:root to nobody:nogroup. but this try was rejected by system.

I thought that this is the not just simple problem to change ownership and permission. maybe this problem came from it's file system.
finally, I tried to change the file system of USB sticks by formatting.
after changing the USB sticks file system to Ext4, my iPad could read and write file on SMB share properly.

conclusion is that iPadOS is write file as nobody:nogroup ownership on SMB share. and exFAT file system is just removable and temporary file system. so, do not use the exFAT for SMB service. Ext4 is highly recommend.

so, if your iPad File-App could not access the SMB share properly, check the disk format type.

Polyester fiber shock

Hi.

today, let's talk about yesterday's funny story.

several years ago, I had a new project that install a bunch of nexus switchs.
but, something weird feeling was sufferd me in working.
when I touch switch chassis, popped with static electricity everytime.
so, I asked around, if you're feeling OK?
but, everyone has no problem. it happened just me.

so I guessed what is the problem. but I can't figure out it.
by chance, when I took off my jacket, and static electricity was gone like magic!
afterwards, I find out that suspect was polyester jacket.

polyester fiber is easy to make static electricity.
so, the static electricity that originated in my jacket was attacked me.

anyway in working, if you wear polyester fiber clothes, change it now.
it's good for you and devices.

have a nice day!

Cisco Jabber installation Guide

Hello!

old video, but maybe useful tutorials here.


Cisco Jabber installation 01 - internal DNS, NTP server setup
https://youtu.be/AfmrRqfc--E


Cisco Jabber installation 02 - external DNS server setup
https://youtu.be/-0mAV1uX73I


Cisco Jabber installation 03 - CUCM, CUP install
https://youtu.be/TU2aAuLlsgw


Cisco Jabber installation 04 - CUCM, CUP setup
https://youtu.be/O-8t98_sjaE


Cisco Jabber installation 05 - Expressway setup & test
https://youtu.be/FKcmMxj9TF0


Cisco Jabber installation 06 - OpenSSL certification issue
https://youtu.be/t-5KBMPX9D8


Cisco Jabber installation 07 - UC ISO bootloader setup
https://youtu.be/UVjIJnFw5KA


good luck!

Hi, migration completed!

Thanks for visit.

for more operational convenience, I have moved to Google Blogger.

Cisco UC ISO Boot loader

Hello


here is Cisco UC ISO Boot loader file.

I had tested successful for CUCM and CUP 10.x to 11.5 version.


cucm 10.x later boot loader.bif



Good luck!