Archive for linux

Transmission network problem

Recently started in debug mode on Transmission and I see:

[17:42:40.319] UDP Failed to set receive buffer: requested 4194304, got 262142 (tr-udp.c:75)
[17:42:40.319] UDP Please add the line "net.core.rmem_max = 4194304" to /etc/sysctl.conf (tr-udp.c:80)
[17:42:40.319] UDP Failed to set send buffer: requested 1048576, got 262142 (tr-udp.c:86)
[17:42:40.319] UDP Please add the line "net.core.wmem_max = 1048576" to /etc/sysctl.conf (tr-udp.c:91)

By tuning the two variables, higher throughput can be achieved more easily using uTP.

Here’s the relevant part from the changeset :

Since we are using a single UDP socket to implement multiple UTP sockets,
and since we are not always timely in servicing an incoming UDP packet,
it is important to use a large receive buffer. The send buffer is probably
less critical, we increase it nonetheless.

Four megabytes might seem huge for embedded clients, but running behind a dedicated connection, it might even become too small. I recommend using 16 megabytes for receive buffering and 4 for the send buffer. That is, because uTP implements a retransmission algorithm and by scaling up the buffers we can achieve fewer retransmits because of dropped datagrams. Let’s set it up that way.

Check actual settings:

do the modifications:

src: https://falkhusemann.de/blog/2012/07/transmission-utp-and-udp-buffer-optimizations/

gigabit e1000e Detected Hardware Unit Hang

If we see it in

the resulution is:

 

for gentoo, add these lines into

 

src: https://serverfault.com/questions/616485/e1000e-reset-adapter-unexpectedly-detected-hardware-unit-hang

Iptables speciális IPről speciális port-ra forwardolás

Tesztelt / Tested:

Source interface: eno1
Target IP: 192.168.100.40

Source Port: 922
Target port: 22

 

NEM TESZTELT! / NOT TESTED!

 

Cert lementése remote szerverről linuxon

 

Keresés tar archivumok fájljain belül

vagy így is megeszi

 

How to get Apache Tomcat version

 

Let’s Encrypt howto

Clone Git repo:

than:

Generate apache config and certs:

or with subdomain

lets test it:

Enable auto renewal:

output be similar like this:

add it to crontab:

add a line:

grep list the whole line which matches

If we needs the whole line

 

apache tomcat multiple instances on gentoo

Examples:

Follow the information in the help to create new Tomcat instances. Tomcat instances use the following layout:

  • /etc/conf.d/tomcat-SLOT-suffix: configuration file for running Tomcat instance services
  • /etc/init.d/tomcat-SLOT-suffix: controlling script for the Tomcat instance
  • /etc/tomcat-SLOT-suffix/: directory containing standard Tomcat configuration files
  • /var/lib/tomcat-SLOT-suffix/: Catalina base directory
  • /var/log/tomcat-SLOT-suffix/: directory for instance log files

Veracrypt mount

Veracrypr mount opció ha az alábbi hibát kapjuk:

 

az alábbi opciót kell kiadni: