As usual, I did the server upgrade. Everything looks OK, except the minecraft is not working.

I check the  status of Minecraft service.

davidyin@minecraft:~$ sudo service minecraft status
○ minecraft.service - Minecraft Server
Loaded: loaded (/etc/systemd/system/minecraft.service; enabled; preset: enabled)
Active: inactive (dead) since Tue 2026-04-07 20:00:58 UTC; 1min 58s ago
Duration: 811ms
Process: 790 ExecStart=/usr/bin/java -Xmx5102M -Xms1024M -jar server.jar nogui (code=exited, status=1/FAILURE)
Process: 876 ExecStop=/opt/minecraft/tools/mcrcon/mcrcon -H 127.0.0.1 -P 25575 -p izpait stop (code=exited, status=1/FAILURE)
Main PID: 790 (code=exited, status=1/FAILURE)
CPU: 233ms

Apr 07 20:00:57 minecraft systemd[1]: Started minecraft.service - Minecraft Server.
Apr 07 20:00:58 minecraft java[790]: Error: LinkageError occurred while loading main class net.minecraft.bundler.Main
Apr 07 20:00:58 minecraft java[790]: java.lang.UnsupportedClassVersionError: net/minecraft/bundler/Main has been compiled by a more recent version of the Java Runtime (class file v
Apr 07 20:00:58 minecraft mcrcon[876]: Connection failed.
Apr 07 20:00:58 minecraft mcrcon[876]: Error 111: Connection refused
Apr 07 20:00:58 minecraft systemd[1]: minecraft.service: Deactivated successfully.

It is clearly mentioned that the problem is with the service.

Apr 07 20:00:58 minecraft java[790]: java.lang.UnsupportedClassVersionError: net/minecraft/bundler/Main has been compiled by a more recent version of the Java Runtime

I checked the official Tutorial. There is a section about Java.

• Minecraft ≥ 26.1 and above requires Java 25.
• Minecraft ≥ 1.20.5 and 1.21.11 requires Java 21.
• Minecraft ≥ 1.18 requires Java 17.
• Minecraft ≥ 1.12 requires Java 8.

Now, I check the Java version on the server.

davidyin@minecraft:~$ java -version
java version "21.0.3" 2024-04-16 LTS
Java(TM) SE Runtime Environment (build 21.0.3+7-LTS-152)
Java HotSpot(TM) 64-Bit Server VM (build 21.0.3+7-LTS-152, mixed mode, sharing)

It is version 21.0.3.

I need a higher version of Java, at least Java 25.

Go to Oracle page
https://www.oracle.com/java/technologies/downloads/#java25

It has Java 26 as well. But I don’t need it. I just need JDK 25 x64 Debian Package.

https://download.oracle.com/java/25/latest/jdk-25_linux-x64_bin.deb

After downloading JDK 25 to the server, I run the following command to install it.

davidyin@minecraft:~$ sudo apt install ./jdk-25_linux-x64_bin.deb
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Note, selecting 'jdk-25' instead of './jdk-25_linux-x64_bin.deb'
The following NEW packages will be installed:
jdk-25
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 0 B/185 MB of archives.
After this operation, 392 MB of additional disk space will be used.
Get:1 /home/davidyin/jdk-25_linux-x64_bin.deb jdk-25 amd64 25.0.2-ga [185 MB]
Selecting previously unselected package jdk-25.
(Reading database ... 129616 files and directories currently installed.)
Preparing to unpack .../jdk-25_linux-x64_bin.deb ...
Unpacking jdk-25 (25.0.2-ga) ...
Setting up jdk-25 (25.0.2-ga) ...
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jar to provide /usr/bin/jar (jar) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jarsigner to provide /usr/bin/jarsigner (jarsigner) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/java to provide /usr/bin/java (java) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/javac to provide /usr/bin/javac (javac) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/javadoc to provide /usr/bin/javadoc (javadoc) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/javap to provide /usr/bin/javap (javap) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jcmd to provide /usr/bin/jcmd (jcmd) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jconsole to provide /usr/bin/jconsole (jconsole) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jdb to provide /usr/bin/jdb (jdb) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jdeprscan to provide /usr/bin/jdeprscan (jdeprscan) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jdeps to provide /usr/bin/jdeps (jdeps) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jfr to provide /usr/bin/jfr (jfr) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jhsdb to provide /usr/bin/jhsdb (jhsdb) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jimage to provide /usr/bin/jimage (jimage) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jinfo to provide /usr/bin/jinfo (jinfo) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jlink to provide /usr/bin/jlink (jlink) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jmap to provide /usr/bin/jmap (jmap) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jmod to provide /usr/bin/jmod (jmod) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jnativescan to provide /usr/bin/jnativescan (jnativescan) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jpackage to provide /usr/bin/jpackage (jpackage) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jps to provide /usr/bin/jps (jps) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jrunscript to provide /usr/bin/jrunscript (jrunscript) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jshell to provide /usr/bin/jshell (jshell) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jstack to provide /usr/bin/jstack (jstack) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jstat to provide /usr/bin/jstat (jstat) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jstatd to provide /usr/bin/jstatd (jstatd) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/jwebserver to provide /usr/bin/jwebserver (jwebserver) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/keytool to provide /usr/bin/keytool (keytool) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/rmiregistry to provide /usr/bin/rmiregistry (rmiregistry) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/bin/serialver to provide /usr/bin/serialver (serialver) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64 to provide /usr/java/jdk-25-oracle-x64 (java_jdk_25_oracle) in auto mode
update-alternatives: using /usr/lib/jvm/jdk-25.0.2-oracle-x64/lib/jexec to provide /usr/bin/jexec (jexec) in auto mode
Scanning processes...
Scanning linux images...

Running kernel seems to be up-to-date.

No services need to be restarted.

No containers need to be restarted.

No user sessions are running outdated binaries.

No VM guests are running outdated hypervisor (qemu) binaries on this host.

Check the Java version again.

davidyin@minecraft:~$ java -version
java version "25.0.2" 2026-01-20 LTS
Java(TM) SE Runtime Environment (build 25.0.2+10-LTS-69)
Java HotSpot(TM) 64-Bit Server VM (build 25.0.2+10-LTS-69, mixed mode, sharing)

Then I restart the Minecraft service and check the status.

davidyin@minecraft:~$ sudo service minecraft restart
davidyin@minecraft:~$ sudo service minecraft status
● minecraft.service - Minecraft Server
Loaded: loaded (/etc/systemd/system/minecraft.service; enabled; preset: enabled)
Active: active (running) since Tue 2026-04-07 20:07:18 UTC; 5s ago
Main PID: 1516 (java)
Tasks: 25 (limit: 7012)
Memory: 503.6M (peak: 503.8M)
CPU: 12.546s
CGroup: /system.slice/minecraft.service
└─1516 /usr/bin/java -Xmx5102M -Xms1024M -jar server.jar nogui

Apr 07 20:07:18 minecraft java[1516]: Unpacking com/mojang/authlib/7.0.63/authlib-7.0.63.jar (libraries:com.mojang:authlib:7.0.63) to libraries/com/mojang/authlib/7.0.63/authlib-7.0.63.jar
Apr 07 20:07:19 minecraft java[1516]: Starting net.minecraft.server.Main
Apr 07 20:07:20 minecraft java[1516]: WARNING: A restricted method in java.lang.System has been called
Apr 07 20:07:20 minecraft java[1516]: WARNING: java.lang.System::load has been called by com.sun.jna.Native in an unnamed module (file:/opt/minecraft/server/libraries/net/java/dev/jna/jna/
Apr 07 20:07:20 minecraft java[1516]: WARNING: Use --enable-native-access=ALL-UNNAMED to avoid a warning for callers in this module
Apr 07 20:07:20 minecraft java[1516]: WARNING: Restricted methods will be blocked in a future release unless native access is enabled
Apr 07 20:07:22 minecraft java[1516]: WARNING: A terminally deprecated method in sun.misc.Unsafe has been called
Apr 07 20:07:22 minecraft java[1516]: WARNING: sun.misc.Unsafe::objectFieldOffset has been called by org.joml.MemUtil$MemUtilUnsafe (file:/opt/minecraft/server/libraries/org/joml/joml/1.10
Apr 07 20:07:22 minecraft java[1516]: WARNING: Please consider reporting this to the maintainers of class org.joml.MemUtil$MemUtilUnsafe
Apr 07 20:07:22 minecraft java[1516]: WARNING: sun.misc.Unsafe::objectFieldOffset will be removed in a future release
lines 1-20/20 (END)

The post Upgrade Minecraft Java Server to 26.1.1 appeared first on David Yin's Blog.

I bought a Logitech MX Vertical mouse in Shanghai.  Chinese Yuan 450, converted to Canadian dollar $90.

It did reduce my muscle strain and decrease wrist pressure.

My right hand and arm are less uncomfortable.

MX Vertical

MX Vertical is a rechargeable device. It provides a USB cable for charging.

MX Vertical can connect to the PC through USB-C cable, Unifying Receiver, or Bluetooth—three ways to connect.

I installed Logi Option+ for settings and configuration.

There is another vertical module, Logitech Lift Vertical. I tried both in the store. I feel the Lift is too light.

The post Logitech MX Vertical M-R0074 appeared first on David Yin's Blog.

Let me copy the history of this church.

History

Rosary Church, Tsimshatsui, was built in 1905 with a generous donation from a Portuguese Catholic, Dr. Antonio S. Gomes.

In 1900, the time of the Boxer Uprising, British military regiments were mobilised to Hong Kong and stationed in Kowloon.

Fr. Spada secured the loan of the Canossian Missionary premises to serve the needs of the Catholic military and lay people.

In 1901, a small church was built. It soon could not meet the local and expatriate needs. In 1903, Dr. Gomes made a generous donation to build a new Church on land released by the Canossian Convent. The foundation stone was laid in December 1904, and Rosary Church was completed in May 1905.

In 1949, Rosary Church was upgraded as a parish. Further extension work of the Church was undertaken and completed at Christmas 1950.

The Church underwent extensive renovation work in 1991. In preparation for the centenary celebration, large-scale renovation and improvement works were undertaken an dcompleted in 2003.

My pictures

The Joyful, Sorrowful and Glorious Mysteries on the wall above the altar remind us of Christ’s nativity, sacrifice and redemption. In 2006, the 5 Mysteries of Light were added to the original 15 Mysteries.

The official site of Rosary Church Kowloon.

There is a small store beside the church. I bought a rosary and a book. Went back into the church. Asking Fr. Cyril CHEUNG for a blessing.

The post Rosary Church Kowloon Hong Kong appeared first on David Yin's Blog.

Let me put the descriptions of them.

 EAP770

BE11000 Ceiling Mount Tri-Band Wi-Fi 7 Access Point.

• BE11000 Tri-Band Wi-Fi 7: 5765 Mbps (6 GHz) + 4324 Mbps (5 GHz) + 688 Mbps (2.4 GHz). Buffering will no longer be a problem.
• 1× 2.5G Port: Unlock the full potential of Wi-Fi 7.
• Clear 6 GHz Band: Brings cleaner and wider band resources to your Wi-Fi.
• 320 MHz Bandwidth: Up to 320 MHz bandwidth enables many more simultaneous transmissions at the fastest possible speeds.
• Low Latency and Interference: Multi-Link Operation, and Multi-RUs ensure high performance of your network.
• Advanced Functions： Supports centralized management, Mesh, and Seamless Roaming

The EAP770 is quite heavy. I mounted one on the ceiling of the main floor. It can cover the area of my 600 sq ft floor. I pulled a CAT5e cable from the basement to it. A Cat5e cable can provide both data and power. The EAP770 is 2.5G PoE+. So it’s quite simple for installation.

Oh, I managed it with Omada Controller software, which is running in a VM.

The second EAP770 AP I installed in the second floor, vertically on the wall. I give it power only. So it is wirelessly connected to the network.

EAP725-Wall

BE5000 Wall Plate Wi-Fi 7 Access Point

• Dual-Band Wi-Fi 7: 4324 Mbps on 5 GHz and 688 Mbps on 2.4 GHz.
• Versatile Ports with PoE Flexibility: 1× 2.5G PoE Input port, 1× 2.5G PoE pass-through port, and 2× Gigabit downlink ports.
• Low Latency and Interference: Multi-Link Operation, Multi-RUs, and 4K-QAM ensure high performance for your network.
• Complete In-Room Wi-Fi Coverage: Guaranteed strong signals and corner-to-corner Wi-Fi coverage up to 750ft² (70 ㎡).
• Flexible Deployment and Easy Setup: Supports 802.3at/bt PoE for flexible installation with Omada SDN for one-click setup.
• Advanced Features: Supports centralized cloud management, Mesh, and Seamless Roaming.
• More Connections: Supports 250+ concurrent connections.

Now the EAP725 is in the basement.

I removed an Ethernet panel that I customized on the bookshelf. Connected the existing CAT5e cable to the EAP725. Mount it on the existing box. Due to the space under it I have to install the EAP725 upside down.

For dust prevention, I 3D printed three RJ45 plugs.

Conclusion:

My house is three levels. I put one AP on each floor. And each AP can cover more than 750 sq ft.

Because the AP is only good for one floor, I implemented three APs on three floors.

I am also using Omada Controller software to manage them. The screenshot below is from Omada Controller.

The post tp-link APs EAP770 and EAP725 appeared first on David Yin's Blog.

Today I took it out and charged it. I am going to use it as a Kiosk tablet.  The very first task is to upgrade the system OS.

I checked the About page of the table. It is Android 6.0.1.

I did a lot of research and tried and failed, then tried again in different ways. Now it is a success.

There are many steps.

Caution:

Theses steps may not 100% nessearary. I just keep them as a record.

You takes all your own risk if you follow these steps below.

Step 0, Install Windows Drivers

The first trial is from an XDA post, https://xdaforums.com/t/guide-tutorial-howto-google-nexus-7-2013-stock-to-android-13.4275457/. It helps me, even though I can not finish them all.

Download the zip file and unzip it. djibe Nexus 7 2013 pack: https://drive.google.com/file/d/1gPo8YGO-5b6mqugCDyi7T3k94uecwbfZ/view?usp=sharing

Go to sub_folder usb_driver_r13_windows/usb_driver， locate the file android_winusb.inf, right click the file and select Install. Confirm with OK to install the driver. Then restart Windows. ( I am using Windows 11, the latest build)

Step 1, Unlock Bootloader of Nexus 7

In the tablet, Android, go to settings > About tablet. Tap 7 times on “build number” to unlock the Developer menu. Go to Settings > Developer options and turn on the switch USB debugging.

Connect tablet to my Windows, yes, through a USB cable.

In Windows command,  Go to the folder which I unzipped before. Enter command,

adb devices

If it is OK, the return is as follows:

077955f1     unauthorized

If it finds nothing, maybe check the table, the authorization, or the confirmation required.

Enter command

fastboot oem unlock

Using Volume+, select Yes – unlock bootloader, confirm by pressing Power.

Then the last message on the tablet screen is : LOCK STATE – unlocked.

Step 2, Install TWRP 3.7.0

fastboot flash recovery twrp-3.7.0_9-1-flo_followmsi.img

The commnd above is to flash the TWRP recovery image to the tablet. My teblet is Wi-Fi only version. So use “flo” image. It is pretty fast. About 1 second, done.

Use Volume to select Recovery mode, confirm with the Power button.

I need an OTG cable and a USB storage. The sanddisk is 16GB.

Format the USB disk as FAT32.

Copy the files unziped before to the disk.

Go to https://drive.google.com/drive/folders/0By6p5AdQfavBUlhsLWFHZThGTnM?resourcekey=0-0BunAmDBWluYPghT0Fs6CA to download lineage-20.0-20230830-UNOFFICIAL-flo.zip, and save it to the USB disk

Go to lineageos.org official site to download Gapps, https://wiki.lineageos.org/gapps/

LineageOS 20(Android13) MindTheGapps ARM file, and save it to the USB disk.

Step 3, Backup

The following steps are mostly from https://blog3c.net/blog/post/284179132-nexus7-2013-os-upgrade

Connect the USB disk to OTG cable, Connect the OTG to the tablet.

Now it is in the TWRP Recovery environment.

Select Mount, choose OTG, the OTG driver is also USB disk.

Select Backup, choose Boot, System and Data, then Select Storage, Choose USB OTG.

Swipe to Backup. It took minutes to finish it.

Step4, Wipe out

Back to the main menu

Select Wipe > Advanced Wipe,  Choose data, system, cache,  Swipe to wipe.

Step 5, Change the petations

Back to the main menu of TWRP

Select Install > Install ZIP

From the folder I unzipped, Choose lanchon-repit-20210221-system=max-cache=16M+wipe-flo.zip

Swipe to confirm Flash

Step 6, Install Magisk v27

Same as step 5. Flash Magisk-v27.0.apk

Step 7, Install Lineage 20.0

Install the lineage-20.0-20230830-UNOFFICIAL-flo.zip

Step 8, Install MindTheGapps 13.0.0

Install the MindTheGapps-13.0.0-arm-20231025_200806.zip

Last Step, Wipe Dalvik Cache and Reboot

The post Asus Nexus 7 (2013) Upgrade the OS to Android 13 appeared first on David Yin's Blog.

OK, the news is I bought a new Canon imageClass MF284dw multifunction laser printer. It is the cheapest one I can find on the market. The MSRP or the market price is $279.99 here and there.

But I found a discount at the Staples store. So I went to a Staples store on Lougheed Highway. The invoice is $279.99 – $100(discount) -$10(coupon) = $169.99. Plus tax and recycling fees, etc., I paid a total of $198.18.

The staff helped me get the printer from the back shelf. He said there is no space for it outside. I am surprised by the size of the box. I have to put down the last row of seats in my car.

The box is big and heavy.

The printer is packed so well. Protected perfectly.

Put both printers side by side. The new MF284dw is slightly larger.

This printer has a lot of features. I would like to highlight my likes.

Core Functions

• 3-in-1 Capabilities: Supports printing, scanning, and copying.
• Fast Monochrome Printing: Reaches speeds up to 35 pages per minute (ppm) for letter-sized documents.
• Quick First Print: Delivers the first page in approximately 4.9 seconds.
• High-Quality Output: Offers a print resolution of 600 x 600 dpi, which can be enhanced up to 1200 x 1200 dpi (equivalent) for sharp text.

Paper Handling

• Auto Duplexing: Automatically prints on both sides of the page to save paper.
• 250-Sheet Paper Cassette: A large-capacity tray that holds up to 250 sheets of plain, letter-sized paper.
• 35-Sheet Auto Document Feeder (ADF): Allows for efficient batch scanning and copying of multi-page documents (simplex only).
• Media Versatility: Supports various sizes including Letter, Legal, Statement, and Executive, as well as envelopes and custom sizes.

Connectivity & Software

• Flexible Connectivity: Connect via Wi-Fi, Ethernet, or USB 2.0.
• Mobile Printing: Compatible with the Canon PRINT app, Apple AirPrint, and Mopria Print Service for printing from smartphones and tablets.
• Chromebook Compatible: Fully supports direct printing from Chrome OS.
• PCL Support: Includes PCL 5 and PCL 6 drivers for broad software compatibility.

Ease of Use & Maintenance

• 5-Line LCD Control Panel: An adjustable monochrome display for easy navigation and status monitoring.
• All-in-One Cartridge: Combines toner and drum into one unit for simple, mess-free replacement.
• High-Yield Toner Option: Compatible with Canon Genuine Toner 072 (1,400-page yield) and 072 High Capacity (4,100-page yield).
• Energy Efficient: ENERGY STAR Certified and rated EPEAT Silver for sustainability.

Here is the official support page of MF284dw.

The post Canon imageCLASS MF284dw appeared first on David Yin's Blog.

Annual payment is $76.32 for 12 months, which is about $6.36/month.

When I SSH to the server, the first thing I want to do is test its performance.

Yet-Another-Bench-Script (YABS)

root@vmi3079413:~# curl -sL yabs.sh | bash -s -- -4
# ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #
#              Yet-Another-Bench-Script              #
#                     v2025-04-20                    #
# https://github.com/masonr/yet-another-bench-script #
# ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## ## #

Wed Feb 11 18:53:19 CET 2026

Basic System Information:
---------------------------------
Uptime     : 0 days, 0 hours, 11 minutes
Processor  : AMD EPYC Processor (with IBPB)
CPU cores  : 6 @ 2794.748 MHz
AES-NI     : ✔ Enabled
VM-x/AMD-V : ❌ Disabled
RAM        : 11.7 GiB
Swap       : 0.0 KiB
Disk       : 96.8 GiB
Distro     : Ubuntu 24.04.4 LTS
Kernel     : 6.8.0-90-generic
VM Type    : KVM
IPv4/IPv6  : ✔ Online / ✔ Online

IPv6 Network Information:
---------------------------------
ISP        : Contabo GmbH
ASN        : AS51167 Contabo GmbH
Host       : Contabo GmbH
Location   : Lauterbourg, Grand Est (GES)
Country    : France

fio Disk Speed Tests (Mixed R/W 50/50) (Partition /dev/sda1):
---------------------------------
Block Size | 4k            (IOPS) | 64k           (IOPS)
  ------   | ---            ----  | ----           ----
Read       | 93.27 MB/s   (23.3k) | 1.14 GB/s    (17.9k)
Write      | 93.51 MB/s   (23.3k) | 1.15 GB/s    (18.0k)
Total      | 186.78 MB/s  (46.6k) | 2.30 GB/s    (35.9k)
           |                      |
Block Size | 512k          (IOPS) | 1m            (IOPS)
  ------   | ---            ----  | ----           ----
Read       | 2.74 GB/s     (5.3k) | 3.08 GB/s     (3.0k)
Write      | 2.88 GB/s     (5.6k) | 3.29 GB/s     (3.2k)
Total      | 5.62 GB/s    (10.9k) | 6.38 GB/s     (6.2k)

iperf3 Network Speed Tests (IPv4):
---------------------------------
Provider        | Location (Link)           | Send Speed      | Recv Speed
-----           | -----                     | ----            | ----
Clouvider       | London, UK (10G)          | 292 Mbits/sec   | 273 Mbits/sec
Eranium         | Amsterdam, NL (100G)      | 290 Mbits/sec   | 295 Mbits/sec
Uztelecom       | Tashkent, UZ (10G)        | 267 Mbits/sec   | 213 Mbits/sec
Leaseweb        | Singapore, SG (10G)       | 235 Mbits/sec   | 226 Mbits/sec
Clouvider       | Los Angeles, CA, US (10G) | 249 Mbits/sec   | 237 Mbits/sec
Leaseweb        | NYC, NY, US (10G)         | 265 Mbits/sec   | 280 Mbits/sec
Edgoo           | Sao Paulo, BR (1G)        | 239 Mbits/sec   | 202 Mbits/sec

iperf3 Network Speed Tests (IPv6):
---------------------------------
Provider        | Location (Link)           | Send Speed      | Recv Speed
-----           | -----                     | ----            | ----
Clouvider       | London, UK (10G)          | 277 Mbits/sec   | 291 Mbits/sec
Eranium         | Amsterdam, NL (100G)      | 278 Mbits/sec   | 291 Mbits/sec
Uztelecom       | Tashkent, UZ (10G)        | 267 Mbits/sec   | 236 Mbits/sec
Leaseweb        | Singapore, SG (10G)       | 246 Mbits/sec   | 215 Mbits/sec
Clouvider       | Los Angeles, CA, US (10G) | 249 Mbits/sec   | 266 Mbits/sec
Leaseweb        | NYC, NY, US (10G)         | 267 Mbits/sec   | 267 Mbits/sec
Edgoo           | Sao Paulo, BR (1G)        | 220 Mbits/sec   | 98.7 Mbits/sec

Geekbench 4 Benchmark Test:
---------------------------------
Test            | Value
                |
Single Core     | 3070
Multi Core      | 10972
Full Test       | https://browser.geekbench.com/v4/cpu/19375138

YABS completed in 10 min 40 sec

Compare to the old one I used before, the CPU scores are much better.

The post Contabo VPS 20 Performance Test appeared first on David Yin's Blog.

Everything is OK. Until I try the update script. I forgot to record the error. So I found one on the Web. As below

15:47:42 [250e8a55b4df40e8c3d5f0dd] [no req]   Error: Class "Wikimedia\Parsoid\DOM\HTMLDocument" not found
15:47:42 Backtrace:
15:47:42 from /workspace/src/vendor/wikimedia/parsoid/src/Utils/DOMCompat.php(112)
15:47:42 #0 /workspace/src/includes/Parser/ContentHolder.php(96): Wikimedia\Parsoid\Utils\DOMCompat::newDocument()
15:47:42 #1 /workspace/src/includes/Parser/ParserOutput.php(368): MediaWiki\Parser\ContentHolder::createEmpty()
15:47:42 #2 /workspace/src/includes/Output/OutputPage.php(439): MediaWiki\Parser\ParserOutput->__construct()
15:47:42 #3 /workspace/src/includes/Context/RequestContext.php(331): MediaWiki\Output\OutputPage->__construct()
15:47:42 #4 /workspace/src/includes/Setup.php(571): MediaWiki\Context\RequestContext->getOutput()
15:47:42 #5 /workspace/src/maintenance/doMaintenance.php(71): require_once(string)
15:47:42 #6 /workspace/src/maintenance/install.php(278): require_once(string)
15:47:42 #7 {main}
15:47:42 <<< Finish: Install MediaWiki, db=<MySQL /workspace/db/quibble-mysql-cd7j8qln/socket>, in 0.191 s

It is a problem between the php8.4 and MediaWiki.
So it is just a workaround to make the upgrade continue and finish.

The problem is that Wikimedia\Parsoid\DOM\HTMLDocument isn't properly autoloaded. I solved it temporarily like this:

require_once('vendor/wikimedia/parsoid/src/DOM/HTMLDocument.php');

Insert this line right before $doc = HTMLDocument::createEmpty( "UTF-8" ); in vendor/wikimedia/parsoid/src/Utils/DOMCompat.php.

Credit to the original post at https://phabricator.wikimedia.org/T409283

Update 2026.1.7

When I try to edit the wiki page, I see a similar problem again.  So I look at the Parsoid in the MediaWiki site.

Parsoid is incompatible with the current MediaWiki release (1.45) if PHP 8.4+ is used. If you need to use Parsoid you’re advised to either use PHP 8.3 or avoid upgrading to 1.45 until this problem is fixed.

So, I decided to downgrade the PHP from 8.4 to 8.3. After that, it is OK.

The post A problem when upgrade Mediawiki installation appeared first on David Yin's Blog.

I like to share some thoughts on my experience.

In the Tapo App, the C560WS camera is shown as above.

When I get into the camera interface. The screenshot gives the most important information here.

There are four icons below the video.

• Take a picture （ Save to Download on my smartphone)
• Record a video（ Save to Download on my smartphone)
• Hear the sound
• Call

Below these four icons, A section for eight features

• Talk
• Pan & Tilt ( I can control the camera direction)
• Alarm ( I don’t use it)
• Privacy Mode
• Light ( The camera has a light built in)
• Tag On ( It is on)
• AI Zoom ( When something moves in the area, it will auto Zoom in)
• Tapo Care

Tapo Care Overview

Tapo Care offers a comprehensive suite of smart monitoring features, including:

• 📸 Rich notifications with snapshots
• 🎞 Video summaries for quick reviews
• 📊 Weekly activity reports
• 🧠 Smart event sorting

Plan Comparison
The only differences between the two plans are the price and cloud storage duration:

Note: The pricing shown in my Tapo App (above) differs from what’s listed on TP-Link’s Canadian website.

The playback and download section is for videos or pictures stored in the cloud or on the local SD card.

Regarding Facial Recognition, it uses Local AI. I believe that it is an important feature for privacy. I don’t want my face or anyone’s face uploaded to the cloud.

Tapo’s facial recognition feature operates using on-device AI, meaning all processing is done locally without sending facial data to the cloud. This enhances privacy and ensures faster, real-time recognition performance.

To use the Facial Recognition feature, I need to upload photos of the people I want the system to recognize.

The summary of the Last 7 days is cool. Press it then I can see how many faces are recorded and recognized. The strangers here is my neighbours and the postman.

There is also another

I do like the Tapo C560WS security camera. There are only two small issues I have.

1) If I block the camera’s internet access via the firewall, it fails to retrieve the correct time, even when the timezone is set properly. My expectation is that once the camera receives the correct time from the internet and I’ve set the timezone, it should continue running its internal clock locally. After that, even if I block internet access via the firewall, the camera should still maintain accurate time independently.

Generally, I would like to keep everything local as much as possible.

I want to recommend the TP-Link Tapo C560WS security camera for your home safety. It is even better when the Tapo App is used with it.

The post Monitor my Front door with TP-Link Tapo C560WS Security Camera appeared first on David Yin's Blog.

Here is the list of the items.

1. Tapo C560WS camera
2. DC Power adapter 12Vx1A
3. Mounting Template Sticker
4. Mounting Bracket x1
5. Mounting Anchors x4
6. Mounting Screws X4
7. Bracket Screws x2
8. Waterproof Seal x1
9. Waterproof Cable Attachment x1
10. Quick Start Guide

There is one positive aspect to the package. Each bag of screws includes one extra screw as a spare.

The DC power adapter has a long wire. I can connect it to the wall receptacle, which is somewhat far away.

There is a card inside the box.

I know these raised dots are Braille, designed for visually impaired people — which is great. However, the QR code currently points to https://www.tp-link.com/us/document/30831/, and that link is unavailable. When I manually change it to https://www.tp-link.com/sg/document/30831/, the setup guide loads correctly. I believe TP-Link needs to fix the issue.

Installation

I installed it on my front door.

Use the receptacle as the center, the length of the power adapter wire as the distance. I find the best spot for the camera.

The wall is a wood panel. So, I don’t need the mounting anchors. Just put the mounting template sticker on the wall, and drill four pilot holes with a 5/64″ drill bit.

Mount the bracket with four mounting screws.

Changed the cable route to the left.

Align and slide the camera base into the bracket.

Use two bracket screws to affix the bracket and camera base.

I am not using an Ethernet cable. The waterproof cable attachments can be assembled to fully close the Ethernet interface.

I connected the power connector to the power adapter — there’s a rubber waterproof seal in between.
Anyway, the camera is installed under the carport, so it won’t be exposed to rain.

Features

• 𝟒𝐊 𝐔𝐥𝐭𝐫𝐚 𝐇𝐃 𝐂𝐥𝐚𝐫𝐢𝐭𝐲 – Experience 4× the resolution of standard 1080p with 18x zoom for sharper images and finer details. Capture license plates, small objects, and more.
• 𝐂𝐨𝐦𝐩𝐥𝐞𝐭𝐞 𝐀𝐫𝐞𝐚 𝐂𝐨𝐯𝐞𝐫𝐚𝐠𝐞 – Enjoy 360º horizontal and 98º vertical views with pan/tilt, letting you monitor more space. The camera’s field of view is greater than the mechanical pan/tilt range.
• 𝐅𝐫𝐞𝐞 𝐀𝐈 𝐃𝐞𝐭𝐞𝐜𝐭𝐢𝐨𝐧 𝐰𝐢𝐭𝐡 𝐅𝐚𝐜𝐢𝐚𝐥 𝐑𝐞𝐜𝐨𝐠𝐧𝐢𝐭𝐢𝐨𝐧 – Reduce unnecessary alerts by being notified only when an unfamiliar face is detected. You can also enable alerts for people, pets, vehicles, and loud sounds such as dogs barking – all with no fees.
• 𝐒𝐦𝐚𝐫𝐭 𝐌𝐨𝐭𝐢𝐨𝐧 𝐓𝐫𝐚𝐜𝐤𝐢𝐧𝐠 – Detects motion within the camera’s field of view, then automatically pans and tilts to track the subject across a 360º viewing range.
• 𝐃𝐞𝐬𝐢𝐠𝐧𝐞𝐝 𝐟𝐨𝐫 𝐖𝐞𝐚𝐭𝐡𝐞𝐫 𝐑𝐞𝐬𝐢𝐬𝐭𝐚𝐧𝐜𝐞 – This camera’s IP66-rated design protects against heavy rain and dust for reliable 24/7 operation.
• 𝐒𝐞𝐜𝐮𝐫𝐞 𝐑𝐞𝐚𝐥-𝐓𝐢𝐦𝐞 𝐋𝐨𝐜𝐚𝐥 𝐏𝐫𝐨𝐜𝐞𝐬𝐬𝐢𝐧𝐠​ – Get faster alerts and more accurate detections with on-device AI that keeps facial recognition and other sensitive data off the cloud – giving you the speed & security with total privacy control.
• 𝐀𝐝𝐚𝐩𝐭𝐚𝐛𝐥𝐞 𝐍𝐢𝐠𝐡𝐭 𝐕𝐢𝐬𝐢𝐨𝐧 𝐌𝐨𝐝𝐞𝐬 – Choose between black-and-white IR, full-color with built-in spotlights and a starlight sensor, or smart auto mode that switches to color when motion is detected.
• 𝐃𝐮𝐚𝐥-𝐁𝐚𝐧𝐝 𝐖𝐢-𝐅𝐢 𝐂𝐨𝐧𝐧𝐞𝐜𝐭𝐢𝐯𝐢𝐭𝐲 – Supports both 5 GHz and 2.4 GHz Wi-Fi bands for range flexibility. The 5 GHz connection offers faster speeds at shorter distances while the 2.4 GHz connection provides a longer range.
• 𝐍𝐨 𝐒𝐮𝐛𝐬𝐜𝐫𝐢𝐩𝐭𝐢𝐨𝐧 𝐒𝐭𝐨𝐫𝐚𝐠𝐞 𝐎𝐩𝐭𝐢𝐨𝐧 – Store recordings on a microSD card at no cost (up to 512GB, sold separately) or subscribe to Tapo Care’s cloud storage.
• 𝐎𝐮𝐫 𝐂𝐲𝐛𝐞𝐫𝐬𝐞𝐜𝐮𝐫𝐢𝐭𝐲 𝐂𝐨𝐦𝐦𝐢𝐭𝐦𝐞𝐧𝐭 – Tapo is a signatory of the U.S. Cybersecurity and Infrastructure Security Agency’s (CISA) Secure-by-Design pledge. This device is designed, built, and maintained, with advanced security as a core requirement.

Yes, it is on the wall. I will post another update for the software, app, etc.

The post TP-Link Tapo C560WS Outdoor Pan/Tilt Security Camera appeared first on David Yin's Blog.

I like the features:

• Outdoor
• Wi-Fi
• Wired
• Full color
• Weatherproof
• 2K

I paid $44.79 with tax.

The other one, I bought from Tmall.com. It is a Chinese Amazon. Shipped to a warehouse, then transported to Canada. It is only CNY149. Converted to Canadian dollars, it is $29.19 only.

It is TL-IPC44AW. The features:

• Fullcolor
• 3MP
• Remote control
• Wi-Fi only

It is designed for indoor use. But I installed it in the backyard, under the deck. So no water exposure.

Setups

C320WS setup

Install the Tapo App on my Google Pixel phone. Follow the instructions, step by step. Add the Camera, and add the WiFi setting.

There is one important point. I will use it in the Synology system. I need to set up a camera account in the Advanced settings. (A set of Username and Password) It will be used to verify the camera.

IPC44AW Setup

It is a kind of weird. I have to install a TP-Link 物联 through an APK file. It needs a mainland China cellphone number to register the account.

Same here, I need to add it to Synology later. So I should add a password to the camera settings in the App. The Username is admin. I can not change it.

Oh, I use IoT SSID for Wi-Fi connection.

Synology Surveillance Station

Front door, I use the C320WS. It has better night screen quality.

C320WS has good video quality. I have a light on the carport.

In the backyard, I use the IPC44AW. Normally nobodyis  there.

Some great points

They both have video and sound. I can talk to the people who stand in front of the camera. I enabled the Event detection for recording.

I installed the DS Cam App on my cellphone. I can check the recording and see the live

There is something I don’t like about it. I posted on my Chinese blog. See the end of that post.

The post TP-Link Security Cameras appeared first on David Yin's Blog.

TP-Link, a leading global provider of consumer and business networking products, announced it has successfully demonstrated Wi-Fi 8 connectivity, transmitting data with a prototype device developed through a joint industry partnership. This achievement represents a major step toward defining the next generation of wireless technology.

The test successfully validated both the Wi-Fi 8 beacon and data throughput, confirming the viability of the technology and marking a critical milestone in Wi-Fi 8 development. This technology is poised to deliver the ultra-reliable wireless performance that the industry will require as more devices and bandwidth-intensive applications come online.

Through ongoing collaboration with ecosystem partners, TP-Link is dedicated to advancing the technologies that will shape the next era of connectivity, offering users unprecedented speed, stability and reliability.

My knowledge is still WiFi 5. It is 802.11ac. So, let me go through the path of the WiFi.

WiFi 8 (802.11bn) is the next-gen WiFi standard. It focused on steady connections, stronger coverage and smoother roaming. Yes, it is what I am expecting for now.

https://www.tp-link.com/ca/wifi8/ 

Get more information about WiFi 8 from TP-Link, the link above.

There are still no WiFi 8 products on the market. The WiFi 7 is the mainstream product in 2025. My existing network is using Deco X90. It is WiFi 6. I am considering upgrading my network.  Let me see if I can do it in 2025.

The post TP-Link WiFi 8 is comming appeared first on David Yin's Blog.

Last week, I upgraded my Wiki from 1.43.1 to 1.44.0. Look at it.

There is a Deprecation notice on top of every page.

<body class="skin-vector-legacy mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Main_Page rootpage-Main_Page skin-vector action-view"><br />
<b>Deprecated</b>: Use of MediaWiki\Skin\Skin::appendSpecialPagesLinkIfAbsent was deprecated in MediaWiki 1.44. [Called from MediaWiki\Skin\Skin::buildSidebar in /home/davidyin/gthree.win/wiki/includes/skins/Skin.php at line 1639] in <b>/home/davidyin/gthree.win/wiki/includes/debug/MWDebug.php</b> on line <b>386</b><br />
<div id="mw-page-base" class="noprint"></div>

I waited a week for the official solution. Today, I upgraded it to v1.44.2. Still has the same problem.

I conducted extensive research on Google and AI conversations. I found the true solution in a Reddit post.

My wiki URL is https://gthree.win/wiki/

So, enter the URL to edit the sidebar https://gthree.win/wiki/index.php?title=MediaWiki:Sidebar

Then add the code **specialpages-url|specialpages to the it.

Save it. Load the wiki page on Firefox. The system is displayed normally.

The post Deprecated notice after MediaWiki 1.44 appeared first on David Yin's Blog.

I check the receptacle of this air fryer. It is live.

Now, I confirmed that the air fryer had a problem.

The original idea is to get a new one, to replace it. After going to Walmart and Costco, I did not see anything that fit my needs.  I just need a one-basket air fryer with a larger capacity.

At the end, I started to Google the solution. I saw a video that has a similar style. Followed the video and I disassembled it.

Give a close look at the switch.

I tried to press the button, but there was no click sound.

I took it down and opened the micro switch. The official name is Normally Open MicroSwitch. It is widely used in Microwaves, ovens, and air fryers. It is a Door switch for critical safety components.

Look at the picture above. A and B are two connectors to the wires; normally, it is open. When C is pressed, the D will move up to touch B, then A and B  are connected.

The A of this broken switch is kind of loose; D does not move up when I press C. The circle indicated the case was dented.

Found the problem, and I can solve it by replacing the switch.

I found some on Amazon.ca.

$13.99 for two.  The measurements of the product are the same as the original one. It is 16A 125V/250V. Same as the old one.

It took one day to reach my front door.

It is a little bit hard to connect it. At last, I did it.

I assembled it. Plugged the power cord. “Beep”, the panel is on. I will try to air fry something for dinner and see if it is good.

The post Repair my Air Fryer appeared first on David Yin's Blog.

I did a little bit of research on the Internet. I found it is because of the OOM, or Out of Memory issue. It means I ran out of all the RAM I gave to the VPS. To specify the problem, I enter a command in the SSH window.

dmesg -T | grep -i "php\|oom"
journalctl -k | grep -i "out of memory"

I found out that Nginx is still in good condition. But the php8.3-fpm was killed because of OOM.

I just restarted the php8.3-fpm service to solve the 502 error. The website has come back to normal.

The more important thing is, I don’t want it to happen again. I hope the php8.3-fpm service can restart when it is killed because of OOM.

So I added two lines to the php8.3-fpm configuration file.

Add the following two lines to the php8.3-fpm.service file [Service] section:

Restart=always
RestartSec=5s

Yeah, I did it.
You can find out that I am still using Webmin.

The post Fix the problem of 502 error appeared first on David Yin's Blog.