Ubuntu 18.04.3 LTS stops working

I’m not a master but also not a beginner in the linux system, I’ve installed Ubuntu 18.04.3 LTS on dual boot with windows 10 and I’ve been facing a big issue in the Ubuntu 18.04.3 LTS. The issue is that the complete OS stops working, like not a single click and it never starts again, I’ve tried waiting for 10 hrs, the only solution is that I have to press the power key of my laptop and start the laptop again. My laptop is powered by core i5-6200U 2.30 GHz x4 4 GB RAM Intel HD Graphics 520 GNOME version: 3.28.2 This issue mostly happens while debugging the android application in my phone (no emulator) or sometimes while working on terminal. I have some Gnome shell extensions installed, can this be the main cause of problem? Also I’ve install the CPU Power Manager to overclock my CPU. I’m expecting a big help from here or I’ll switch to manjaro, as I’ve tried reinstalled the complete OS.

Server stops accepting connections after ~120,000 active on 18.04.3

I’m running a type of perf test where I have a simple TCP server with 4 IP addresses that is listening on a port and getting connections from several other computers on the local network. Everything works fine up to just under 120,000 active connections, clients are able to get messages from client and create new connections. At just under 120,000, new connections just stop appearing. There is no log activity on server and clients start getting timeouts after a bit. There is no firewall that would be getting in the way. I have tweaked a bunch of settings already:

/etc/sysctl.conf

net.core.netdev_max_backlog = 1000000  net.core.netdev_budget = 50000 net.core.netdev_budget_usecs = 5000  net.core.somaxconn = 1024000  net.core.rmem_default = 1048576 net.core.rmem_max = 16777216  net.core.wmem_default = 1048576 net.core.wmem_max = 16777216  net.core.optmem_max = 65536  net.ipv4.tcp_rmem = 4096 1048576 2097152 net.ipv4.tcp_wmem = 4096 65536 16777216 net.ipv4.udp_rmem_min = 8192 net.ipv4.udp_wmem_min = 8192 net.ipv4.tcp_fastopen = 3 net.ipv4.tcp_max_syn_backlog = 3000000 net.ipv4.tcp_max_tw_buckets = 2000000  net.ipv4.tcp_tw_reuse = 1 net.ipv4.tcp_fin_timeout = 10 net.ipv4.tcp_slow_start_after_idle = 0 net.ipv4.tcp_keepalive_time = 60 net.ipv4.tcp_keepalive_intvl = 10 net.ipv4.tcp_keepalive_probes = 6 net.ipv4.tcp_mtu_probing = 1 net.ipv4.tcp_syncookies = 1 net.ipv4.tcp_rfc1337 = 1 net.ipv4.conf.default.rp_filter = 1 net.ipv4.conf.all.rp_filter = 1 

/etc/security/limits.conf

* soft nofile 6553600 * hard nofile 6553600 

The limits are intentionally completely overkill because it’s just a test. Are there some other settings I am missing that would enable more connections? Neither the CPU nor RAM is being stressed so I would like to keep pushing the hardware. Server and clients are all running on AWS EC2 t3a.xlarge instances, if that makes any difference.

Ubuntu 18.04.3 doesn’t recognize 2. montor after running these commands

I executed these commands:

sudo bash -c "echo blacklist nouveau > /etc/modprobe.d/blacklist-nvidia-nouveau.conf"  sudo bash -c "echo options nouveau modeset=0 >> /etc/modprobe.d/blacklist-nvidia-nouveau.conf"  sudo update-initramfs -u  sudo reboot 

But after rebooting, my 2. monitor is black and Ubuntu is not able to detect it. I went to Settings->Devices->Display and now I can only see my main monitor and not my second. Before running these commands, everything worked. How can I redo this?

I ran this commands in reference to this post.

Ubuntu 18.04.3 Keeps Going To Sleep After I Re-Open Laptop

So for a while I’ve wanted to switch over to Linux. I chose Ubuntu because I thought it would be really easy to transition from Windows. However, I’ve had a myriad of problems but the worst one is that if I close my laptop and then re-open it, sign in, after about 10 seconds the laptop just goes back to sleep. This continues until I restart my laptop. I’m new to Linux but am comfortable navigating the terminal a bit. Any help is appreciated thank you.

Ubuntu 18.04.3 Keeps Going To Sleep After I Re-Open Laptop

So for a while I’ve wanted to switch over to Linux. I chose Ubuntu because I thought it would be really easy to transition from Windows. However, I’ve had a myriad of problems but the worst one is that if I close my laptop and then re-open it, sign in, after about 10 seconds the laptop just goes back to sleep. This continues until I restart my laptop. I’m new to Linux but am comfortable navigating the terminal a bit. Any help is appreciated thank you.

Dell Inspiron 3538 (with Qualcomm Atheros QCA9377) has weak Wi-Fi signal on Ubuntu 18.04.3 LTS

Yesterday I bought Dell’s Inspiron 3538 with preinstalled Ubuntu 18.04.3 LTS.

Everything works pretty much fine (well, there were minor issues as missing a language, a timezone and a region during setup which normally do not miss with vanilla Ubuntu) except Wi-Fi.

For some reason Wi-Fi signal is blatantly weak. First I went to Additional Drivers, there was a wireless device first time I opened Additional Drivers, now it is missing, Ubuntu is not showing it anymore. So I cannot change driver there.

Then I tried installing backports according to this question. I tried few versions, none of them helped. Kernel I am using is 4.15.0-1057-oem.

I really do not know what to do next except installing another kernel (which one?) or just removing preinstalled Ubuntu, download vanilla Ubuntu and install it.

Which is really bad because I bought this Dell explicitly because of its support for Ubuntu and I expected everything to be smooth.

Ubuntu 18.04.3 LTS Update breaks Wireless Adapter : Qualcomm Atheros QCA9377

I have run into a problem. I recently updated my Ubuntu partition (dual-boot with Win10) to 18.04.3 LTS on my Dell Inspiron 17 3000 laptop. Upon restart, the OS no longer recognizes my wireless adapter. Running lspci | grep -i "Wireless\|WiFi" produces: 02:00.0 Network controller: Qualcomm Atheros QCA9377 802.11ac Wireless Network Adapter (rev 31) Running dmesg | grep -i firmware produces:

[     0.135169] Spectre V2 : Enabling Restricted Speculation for firmware calls [     0.208518] ACPI : [Firmware Bug]: BIOS _OSI(Linux) query ignored ... (psmouse and dmc normal messages, irrelevant to problem) [     17.269597] ath10k_pci 0000:02:00.0: firmware ver WLAN.TF.2.1-00021-QCARMSWP-1 api 6 features wowlan,ignore-top crc32 42e41877 

Running rfkill list all produces:

0: hci0: Bluetooth         Soft blocked: no         Hard blocked: no 

Running uname -a produces: Linux user-ubuntu 5.0.0-31-generic #33~18.04.1-Ubuntu SMP Tue Oct 1 10:20:39 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux If there is any more information you need, please tell me; I am still a n00b. (I was actually using this partition to teach me Ubuntu) Thank you!