Remember that control connections are established on port 1723 and then actual data is transferred over GRE protocol 47.
If you have a NAT setup this will work without special forwarding or accepting of GRE packets (normally if you are not blocking outgoing connections and accepting established and related connections).
The below two commands will get things going so PPTP and GRE work
We first load the ip_nat_pptp module which allows PPTP to work with........
The easiest way for the current running kernel is:
update-initramfs -u -k `uname -r`
You could change -k to a specific kernel name if for some reason the current is not running (eg. if you are chrooted or in recovery mode).
If you want to update all kernels then use "-k all"
What if initramfs fails because it tries to update a non-existent kernel that is not installed and not in /boot?
This article about migrating to a CentOS 7 /8 RAID mdadm array has a lot of info but I wanted to focus specifically on what newer versions of CentOS 7 require to boot mdadm and what changes are necessary on CentOS 7.8+
CentOS 7 / 8 mdadm RAID booting requirements
This assumes you are chrooting into an existing install or using it to get a new deployment ready. However, these steps can........
The easiest way for the 8821AU Realtek Wifi chipset / TP-Link T2U Plus:
Bus 002 Device 003: ID 2357:0120 TP-Link Archer T2U PLUS [RTL8821AU]
First install your kernel headers/source:
sudo apt install linux-headers-`uname -r`
Clone this github repo with the driver:
git clone https://github.com/morrownr/8821au-20210708
Run the compile/install:
There aren't too many simple guides that show you how to use commands to setup your USB or other drive as a normal bootable drive where you can easily boot custom kernels or whatever OS you would like.
1. Get the tools we need:
We install "syslinux" for MBR and "syslinux-efi" for EFI and "MBR" as we need a tool that embeds the actual MBR into our USB:
sudo apt install syslinux syslinux-efi mbr........
If you are using the stock 5.4 kernel this is normal but I can confirm it is fixed in newer 5.8 kernels.
To fix it just install the 5.8 kernel and reboot:
sudo apt install linux-headers-5.8.0-64-generic linux-modules-extra-5.8.0-64-generic linux-image-5.8.0-64-generic........
Traditionally kernels were numbered starting from 0 but by default the "new style" of grub boot loading considers each subkernel item to be different so if you have 3 entries for 4.40-148 rather than counting for 1.
To get the expected behavior let's show this example and how we can boot it
We do a grep on menuentry in /boot/grub/grub.cfg to see all of the bootable kernels rather than scrolling through loads of extra entries we don't care about (thou........
You should only get this if you are using a Pentium II or something really old. The problem here is that newer kernels than 2.6 don't have true i386 support even if you tell it to compile as i386. It will still include features like cmov that break older computers from being able to work.
Generally for very old computers like above, you need to use a 2.6.x kernel and of course make sure it is i386 and all the binaries are as well.
apt install software-properties-common
apt install python3-pip
apt install python3.7 curl gnupg python3.7-dev git
ln -s /usr/bin/python3.7 /usr/bin/python3
pip3 install numpy keras_preprocessing
curl https://bazel.build/bazel-release.pub.gpg | sudo apt-key add -
echo "deb [arch=amd64] http://storage.googleapis.com/bazel-apt stable jdk1.8" | sudo tee /etc/apt/sources.list.d/bazel........
I used to believe that for Desktops especially that the "ondemand" CPUfrequency changing that kernels included with Ubuntu and Debian based distros have would be sufficient for snappy performance.
However, you can feel the lack of performance on the fastest computer if you have ondemand. A lot of times even under high load 100% of your CPUfrequency in MHz will not be used.
For example a 2.8Ghz CPUmay only run at 1.8MHz or even .9GHz. Now........
This problem has been around forever, Linux seems to think it is fine to use the r8169 driver for an r8168 NIC but this often causes problems including the link not working at all.
In my case ethttool shows the link up and detected but it simply does not work especially on a laptop that has been resumed from suspension. Sometimes it takes several minutes for it to work or to unplug and replug the ethernet.
Here is the solution:
I think this is more so an issue with kernel modules not being included. I had this issue on Linux Mint because a new kernel I upgraded to DIDNOT have the "extra" modules and part of that reason is also because older kernels are named differently than new ones.
Take this example article below that shows it in action.
If you were previously........
If you've just installed VBox and it is not starting or working, the most common problem is usually that you don't have your kernel source installed, which means there is no kernel driver for vbox so it can't work.
You may get an error that says "Kernel driver not installed" in your Virtualbox.
So the first thing you should do is install your kernel source by running this:
sudo apt-get install linux-headers-`uname -r`........
Iam not sure why this is happening neither the hostnode or VM changed. All I did was reboot the hostnode and startup the Centos VM again, also note it happened with the original kernel on the VM and also the latest 6.9 kernel as of this writing as shown below.
Host Node: Centos 6.9
Same result in any kernel above........
This is a 8TB Seagate external USB 3.0 device apparently newer kernels use a module called "UAS" instead of "USB Storage" which causes issues as a lot of devices are not properly supported in UAS mode by the kernel driver. The solution some say is to disable UAS specifically for your USB device but I'd rather just disable UAS altogether.
Solution blacklist UAS: *do not do this it does not work and just causes your USB 3.0........
2017-01-12 14:25:36 529 (ERROR): The installer was unable to verify that your kernel supports IPv6.
2017-01-12 14:25:36 530 (ERROR): The message received when trying to create an IPv6 socket was Address already in use
2017-01-12 14:25:36 531 (ERROR): Please ensure that the ipv6 module is enabled and loaded in your kernel.
2017-01-12 14:25:36 532 (FATAL): Exiting...
Now many people report this card simply not working in various Linux distros and kernels. My issue is different, it always works at 100mbit (eg. plugged into a 100mbit switch) but no matter what 1000M/gigabit switch I would try, it would never work.
The link would be up (the lights were on) and the OS detected the link as being up as well but it wouldn't work at all and could not pass data in or out (not even a ack/ping).
There is one simple solution and command........
Tired of checking iotop and seeing that your drbd partition is using 99.99% of io all the time and finding your drbd device performs slow in general?
This is especially an issue in versions of DRBD in the 8.3 tree in particular one documented case is on "8.3.13" but it likely applies to other devices.
The symptoms are that resyncing is fine and normal but any reasonable amount of activity is very slow and lagged and creates a high server load and con........
The solution was to reinstall the vbox dkms package and do a manual modprobe of the modules it makes.
I never sorted out the unable to start due to the USB issue, I did have the guest additions installed but the only way to boot was to change the pointing device from USB to PS2 and then to disable the USB controller (if your pointing device is set as USB, disabling USB will not work because it will re-enable by default when it sees your pointing device is USB, this is w........
[ 2868.041375] ata1: EH in SWNCQ mode,QC:qc_active 0x40 sactive 0x40
[ 2868.041554] ata1: SWNCQ:qc_active 0x40 defer_bits 0x0 last_issue_tag 0x6
[ 2868.041556] dhfis 0x40 dmafis 0x40 sdbfis 0x20
[ 2868.041874] ata1: ATA_REG 0x41 ERR_REG 0x84
[ 2868.042013] ata1: tag : dhfis dmafis sdbfis sactive
[ 2868.042163] ata1: tag 0x6: 1 1 0 1
[ 2868.042301] ata1.00: exception Emask 0x1 SAct 0x40 SErr 0x400000 action 0x6 frozen
./configure: line 91: cd: /lib/modules/2.6.32-042stab084.25/build: No such file or directory
Error: kernel version not found.
Please make sure your kernel is configured.
dr-xr-xr-x. 4 root root 4096 Feb 21 06:13 ..
lrwxrwxrwx 1 root root 45 Feb 21 06:13 build -> ../../../usr/src/kernels/2.6.32-042stab084.25
drwxr-xr-x 2 root root 4096 Feb 12 20........
./configure: cannot locate gcc 3.x. please install it or specify with --qemu-cc
yum -y install gcc make
./configure: cannot locate gcc 3.x. please install it or specify with --qemu-cc
yum -y install compat-gcc-*
Error: Could not find alsa
Make sure to have the alsa libs and headers installed.
yum -y install alsa-lib-devel
On the same OS with the same kernels basically I cannot boot FreeBSD installer, I believe the issue is the host CPU.
One host runs an Intel and works, while an Opteron 2373 does not work despite suggestions from this thread: http://18.104.22.168/showthread.php?t=36761
I've tried cpu options like "kvm64" "Opteron_G3" and none........
Linux box13. 2.6.32-042stab076.5 #1 SMP Mon Mar 18 20:41:34 MSK 2013 x86_64 x86_64 x86_64 GNU/Linux
even setting privvmpages to a specific setting DOES not affect "free -m" in containers.
This is probably a kernel issue
23:36:29 up 159 days, 7:12, 4 users, load average: 0.42, 0.44, 0.33
[root@box13 ~]# free -m
-bash-3.1# shutdown -rn now
Connection to localhost closed by remote host.
Connection to localhost closed.
Sometimes I work with embedded systems/custom kernels without any of the fancy init scripts and other common Linux basics that most would expect. This means that often the "reboot" command (which uses an init script) will never work, not only that but it will hang the server and a manual power cycle or reboo........
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03)
For whatever reason it seems the r8169 driver that ships and has shipped with most Linux distros for years is still flawed and does not work properly on these cards, causing 100mbit connectivity when it should be 1gbit and even worse, causing random network dropouts. The r8169 driver in Linux kernels is simply not meant to be used on th........
Inever started these processes but they are from a custom based bootable Linux I've made and I've never seen this behavior on other machines or even with the same machine using different kernels. These processes seemed to spawn on their own and I have no idea why and even worse why the CPU usage is so high?
Here's the output from top:
907 extaudit 30 10 0 0 0 R 90.7 0.0........
This is so handy, especially if you need things like old kernels etc..., this is the main and practically only place you'll ever find what you need.
I dread updating the kernel and rebooting to find the Ubuntu graphics aren't working and you have to manually intervene. This is usually because Ubuntu for whatever reason didn't update the drivers you need (eg. the manually compiled Nvidia Kernel driver that MUST be recompiled for each and every kernel update unfortunately).
The most common reason may be that "linux-source" hasn't been installed automatically on my system. I tried to manually reinstall the........
CPT ERR: cc4c0800,28000 :Unknown image version: 304. Can't restore.
This happens when you live migrate between OpenVZ servers with different kernels running, at least significantly different by date.
There is no solution except to make sure you're running the same kernels on all machines, or at least not kernels that are much older or different (this is just a guess though, you should ensure all kernels are the same).........
I've only used it on Centos, soI thought I'd make a quick Debian guide:
Install the DRBD Package
apt-get install drbd8-utils
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
Use 'apt-get autoremove' to remove them.
had trouble trying to revert Ubuntu 10.04 LTS from grub2, won't boot mdraid and did not even install mdadm during the installation!
I have tried moving back to GRUB 0.97
backed up original /boot and then copied /boot from an old Debian install. Modified device.map and menu.lst and put the appropriate kernels and initrd for Ubuntu back in /boot
I ran grub:
grub> setup (hd0)
Checking if "/boot/grub/stage1........
You'll see the following and the boot process will freeze:
io scheduler noop registered
io scheduler anticipatory registered
io scheduler deadline registered
io scheduler cfq registered (default)
I have struggled with this issue on vari........
I'm using Ubuntu 8.04 but anyone using older kernels will find this may apply to them. My Intel graphics are very slow with the default Xorg settings but by using "EXA" acceleration, scrolling down windows of text becomes pretty snappy.
Just edit /etc/X11/xorg.conf
Identifier "Configured Video Device"
I'm not impressed with this motherboard, I was impressed with my Gigabyte AM3 board which seems to work flawlessly.
Everyone knows that the firmware is flawed, even though I have the F6, it still seems that the system doesn't reset properly or quickly enough.
Another HUGE problem is that in most Linux kernels the NIC won't work (if you try 10 times by rebooting it might). I also notice that you need to power down for it to work.
This board does not seem very com........
drivers/message/fusion/mptsas.c: In function `mptsas_port_delete':
drivers/message/fusion/mptsas.c:106: sorry, unimplemented: inlining failed in call to 'mptsas_set_rphy': function body not available
drivers/message/fusion/mptsas.c:462: sorry, unimplemented: called from here
make: *** [drivers/message/fusion/mptsas.o] Error 1
make: *** [drivers/message/fusion] Error 2
Updated to Version 3.8 and can't loginSSHD accepts my password but then hangs at "Last login: Wed Sep 13 21:30:02 2006 from"
This occurred during a yum update after upgrading my release, installing the new kernel and rebooting.
I got kicked out of sshd after seeing the following during yum update:
telnet 100 % done 85/476
tux 100 % done 86/476
ntsysv 100 % done 87/476
rpmdb-redhat 94 % done 88/476........
*This is a bug with initramfs support, all kernels after around 22.214.171.124 suffer from this problem.
If you try to include initramfs into your kernel (I mean actually building your binaries into the kernel) this will always happen. Obviously some code has changed in recent kernels that is present in all new kernels, it makes it impossible to boot
I've tried the latest 2.6.32, 2.6.33, 2.6.34, 2.6.35, 2.6.36, 2.6.37, 2.6.38 kernels and they all do this. I found one bug re........
I've tried to find a good sensible solution to cluster with and each technology has it's pros and cons and there is no perfect solution and I've found a lot of "exaggerations" in the applications, benefits and performance of these different filesystems.
I first started off with DRBD and Ihave to say it does live up to the hype, is quite reliable (although it can be annoying to match up the kernel module and user applications since they must match and whe........