I installed tftpd-hpa and tftp in Ubuntu 12.04 LTS.
when I check the status of tftpd-hpa with service command, it shows running.
zlf#ubuntu:~$ service tftpd-hpa status
tftpd-hpa start/running
But when I check its process, there is no running PID to show.
zlf#ubuntu:~$ ps -ef |grep ftp
zlf 5607 5397 0 15:02 pts/1 00:00:00 grep --color=auto ftp
zlf#ubuntu:~$ ps -ef |grep hpa
zlf 5609 5397 0 15:02 pts/1 00:00:00 grep --color=auto hpa
what happened? Is tftpd-hpa not a process or other reason?
By the way, I test tftpd-hpa by localhost, it doesn't work.
zlf#ubuntu:~$ tftp localhost
tftp> get test
Transfer timed out.
TFTP requests are probably handled by inetd/xinetd.
Related
In my custom linux image using netstat 1.42 (2001-04-15) from the package net-tools 1.60 I am seeing different behaviors for different linux versions..
On Linux 5.4.28:
# netstat -tnp | grep ESTABLISHED
tcp 0 0 <local_ip>:22 <client_ip>:14321 ESTABLISHED 29342/1
tcp 0 40 <local_ip>:22 <client_ip>:22470 ESTABLISHED 28443/0
On Linux 5.10.65:
# netstat -tnp | grep ESTABLISHED
tcp6 0 52 <local_ip>:22 <client_ip>:22470 ESTABLISHED 1/init
tcp6 0 52 <local_ip>:22 <client_ip>:33679 ESTABLISHED 1/init
The thing to note here is that on Linux 5.10, netstat shows PID as 1 and process as init for all ssh sessions. But in older linux, I am seeing correct PIDs for all ssh sessions. I need to know the client_ip and the PID for every ssh session so I can kill the session for whichever client I want.
From online searches, I could not figure out any fixes.
One alternative that I can see till now is using who to get this output:
# who
root pts/1 00:00 Jan 12 07:16:19 <client_ip>
root pts/2 00:03 Jan 12 08:21:07 <client_ip>
grep this with client_ip then use ps and grep that with the second column, like ps | grep pts/1 for first client.
Is there anything I can do to netstat to fix this though? Because netstat also give the client port which is useful for me.
I wanted to run an fsck check on my 5TB external hard drive on my raspberry pi.
This is the output:
$ sudo e2fsck -c -v /dev/sda
e2fsck 1.44.5 (15-Dec-2018)
Checking for bad blocks (read-only test): 0.46% done, 5:04 elapsed. (0/0/0 errors)
There has been zero progress for hours now. The elapsed time is stuck as well. This is actually my second attempt. Before I tried sudo e2fsck -p -c -v /dev/sda. This one doesn't give any output, that's why I let it run for a whole week before terminating.
My drive is unmounted, partitionless, and freshly formatted with mkfs.ext4. Output from ps:
$ ps -a
PID TTY TIME CMD
1075 tty1 00:00:00 bash
8404 pts/1 00:00:00 sudo
8405 pts/1 00:00:04 e2fsck
8446 pts/1 00:00:00 sh
8447 pts/1 00:00:05 badblocks
23605 pts/2 00:00:00 ps
I noticed on my first attempt, that it was impossible to send a SIGINT, SIGTERM, or SIGKILL to badblocks.
Why is this?
I'm trying to kill a redis server that was started with --daemonize yes
I feel like this should be easy, but I am unable to successfully kill it based on standard methods. I'm using Redis 3.2 installed via these instructions: https://www.hugeserver.com/kb/install-redis-debian-ubuntu/
$ redis-server --daemonize yes
1550:C 13 Mar 05:54:55.436 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
1550:C 13 Mar 05:54:55.437 # Redis version=4.0.8, bits=64, commit=00000000, modified=0, pid=1550, just started
1550:C 13 Mar 05:54:55.437 # Configuration loaded
$ kill 1550
-bash: kill: (1550) - No such process
$ kill -9 1550
-bash: kill: (1550) - No such process
$ killall redis-server
redis-server(1181): Operation not permitted
redis-server: no process found
$ /etc/init.d/redis-server stop
[....] Stopping redis-server (via systemctl): redis-server.service==== AUTHENTICATING FOR org.freedesktop.systemd1.manage-units ===
Authentication is required to stop 'redis-server.service'.
Authenticating as: Ubuntu (ubuntu)
Password:
Why should I need to enter a password to stop it? I never set a password when i started it. And why doesn't kill work? Even if I sudo it, it just restarts again after.
-------------------EDIT-------------------
Additional information. Using the kill command on the process ID doesn't work. I have to use sudo kill but then it comes back with another processid as if something restarts it. I just killed it 3 times and it's back again with a 4th processid –
---------- Solution thanks to #Kevin Law ----------
I needed to kill the daemonized service and then kill the process. Not just one or the other...
ubuntu#ip-MyIPAddress:~/Relayer$ ps -ef | grep redis-server
ubuntu 2381 1 0 18:39 ? 00:00:00 redis-server *:6379
ubuntu 2386 1358 0 18:39 pts/0 00:00:00 grep --color=auto redis-server
ubuntu#ip-MyIPAddress:~/Relayer$ sudo service redis-server stop
ubuntu#ip-MyIPAddress:~/Relayer$ ps -ef | grep redis-server
ubuntu 2381 1 0 18:39 ? 00:00:00 redis-server *:6379
ubuntu 2418 1358 0 18:39 pts/0 00:00:00 grep --color=auto redis-server
ubuntu#ip-MyIPAddress:~/Relayer$ kill 2381
ubuntu#ip-MyIPAddress:~/Relayer$ ps -ef | grep redis-server
ubuntu 2420 1358 0 18:39 pts/0 00:00:00 grep --color=auto redis-server
ubuntu#ip-MyIPAddress:~/Relayer$
There are three options for your question from my test.
Stop redis by stoping redis service. This is the recommend way in most cases.
sudo systemctl stop redis-server
or
sudo service redis-server stop
connect to this redis-server and shutdown it by redis-cli.
redis-cli
after connected to redis, issue shutdown to turn off redis-server
shutdown
Kill the redis-server process directly:
ps -ef | grep redis-server
kill -9 (pid)
Try following command to find the redis-server instances that are running and then try killing the exact instance with kill command.
ps -aef | grep redis
Using Apache2 on Linux, I get this error message when trying to start it.
$ sudo /usr/local/apache2/bin/apachectl start
httpd not running, trying to start
(98)Address already in use: make_sock: unable to listen for connections on address 127.0.0.1:80
no listening sockets available, shutting down
Unable to open logs
$ sudo /usr/local/apache2/bin/apachectl stop
httpd (no pid file) not running
Some facts:
This is one of the last lines in my Apache logs:
[Mon Jun 19 18:29:01 2017] [warn] pid file /usr/local/apache2/logs/httpd.pid overwritten -- Unclean shutdown of previous Apache run?
My '/usr/local/apache2/conf/httpd.conf' contains
Listen 127.0.0.1:80
I have "Listen 80" configured at '/etc/apache2/ports.conf'
Disk is not full
I've checked that I do not have two or more "Listen" at '/usr/local/apache2/conf/httpd.conf'
Some outputs:
$ sudo ps -ef | grep apache
root 1432 1 0 17:35 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 1435 1432 0 17:35 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 1436 1432 0 17:35 ? 00:00:00 /usr/sbin/apache2 -k start
myuserr 1775 1685 0 17:37 pts/1 00:00:00 grep --color=auto apache
$ sudo grep -ri listen /etc/apache2
/etc/apache2/apache2.conf:# supposed to determine listening ports for incoming connections which can be
/etc/apache2/apache2.conf:# Include list of ports to listen on
/etc/apache2/ports.conf:Listen 80
/etc/apache2/ports.conf: Listen 443
/etc/apache2/ports.conf: Listen 443
What can I do to restart Apache? Should I repair 'httpd.pid'?
This error means that something already uses 80 port.
If you really don't have 2 line of Listen 80 in apache configurations then execute this command to see what uses 80 port: netstat -antp | grep 80.
I fixed it by killing the three processes
root 1621 1 0 18:46 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 1624 1621 0 18:46 ? 00:00:00 /usr/sbin/apache2 -k start
www-data 1625 1621 0 18:46 ? 00:00:00 /usr/sbin/apache2 -k start
However, each time I want to reboot my server, I must kill thee processes. What is starting them?
Trying to stop Apache2 service, but get PID error:
#service apache2 stop
[FAIL] Stopping web server: apache2 failed!
[....] There are processes named 'apache2' running which do not match your pid file which are left untouched in the name of safety, Plea[warnview the situation by hand. ... (warning).
Trying to kill, those processes:
#kill -9 $(ps aux | grep apache2 | awk '{print $2}')
but they get re-spawned again:
#ps aux | grep apache2
root 19279 0.0 0.0 4080 348 ? Ss 05:10 0:00 runsv apache2
root 19280 0.0 0.0 4316 648 ? S 05:10 0:00 /bin/sh /usr/sbin/apache2ctl -D FOREGROUND
root 19282 0.0 0.0 91344 5424 ? S 05:10 0:00 /usr/sbin/apache2 -D FOREGROUND
www-data 19284 0.0 0.0 380500 2812 ? Sl 05:10 0:00 /usr/sbin/apache2 -D FOREGROUND
www-data 19285 0.0 0.0 380500 2812 ? Sl 05:10 0:00 /usr/sbin/apache2 -D FOREGROUND
And though the processes are running i can't connect to the server on port 80. /var/log/apache2/error.log.1 has no new messages when i do the kill -9.
Before I tried to restart everything worked perfectly.
Running on Debian: Linux adara 3.2.0-4-amd64 #1 SMP Debian 3.2.54-2 x86_64 GNU/Linux
UPD:
also tried apache2ctl:
#/usr/sbin/apache2ctl -k stop
AH00526: Syntax error on line 76 of /etc/apache2/apache2.conf:
PidFile takes one argument, A file for logging the server process ID
Action '-k stop' failed.
The Apache error log may have more information.
but there is no pid file in /var/run/apache2
I'm new to linux, looks like it has to do something with startup scripts, but can't figure out what exactly.
Below is the command to find out the process running on port 80
lsof -i tcp:80
Kill the process with PID.Restart the system once to check if their is any start up script executing and using the Port 80 which is preventing you to start your service.
For start up scripts you can check
/etc/init.d/ or /etc/rc.local or crontab - e
You can try Apache official documentation for stop/restart operations.
link