A lot of times busy servers will have this issue and you cannot even force kill -9 the apachectl or httpd process:
[root@apachebox stats]# ps aux|grep httpd
root 1547 0.0 0.2 495452 32396 ? Ds Sep08 3:23 /usr/sbin/httpd
root 3543 0.0 0.0 6448 724 pts/1 S+ 13:11&nbs........
Adjust to suit your needs. Currently this would kill any whois process running for more than 30 seconds or more than 1 minute.
Add it as a cronjob. The motivation is that some commands have no timeout and just end up using up CPU and memory for no reason while never exiting to free resources.
IFS=$(echo -en "nb")
for pid in `ps aux|grep whois`; do
sshcommand="ssh -N -R 20000:localhost:22 email@example.com"
result=`ps aux|grep $sshcommand"|grep -v grep`
if [ -z "$result" ]; then
echo "we are going to connect"
echo "we are already connected"
This is a handy script you can use and then add it to cron.
systemd is like the service manager for your Centos and other modern Linux distributions (including Debian/Mint/Ubuntu) allows you to enable services, stop them, restart them, check their status and even reboot your system.
The key commands or arguments you will use with systemctl are the following:
list-units [PATTERN...] List loaded units
sudo apt-get install hwloc-nox
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following NEW packages will be installed:
0 upgraded, 1 newly installed, 0 to remove and 530 not upgraded.
Need to get 151 kB of archives.
After this operation, 453 kB of additional disk space will be used.
The folder contents could not be displayed
Backend currently unmounting
drwx------ 10 userhere group 260 Aug 23 19:40 ..
?????????? ? ? ? ? ? sftp:host=192.168.8.80,user=adhoc
ls: cannot access 'sftp:host=192.168.8.80,user=adoc': Input/output error
$ ps aux|grep fuse
yes it does create its own json
cat /tmp/vcsaUiInstaller/ovftool-20180809-175238948-20180809-175603497.log |grep -i json
2018-08-09T17:56:04.238-07:00 verbose OVFTool [Originator@6876 sub=Default] Manifest file entry: SHA1(VMware-vCenter-Server-Appliance-126.96.36.19900-8832884_OVF10-file1.json) = 1deb658c724767697587d5909c4051c01813e6a1
sudo apt-get install libcurl4-openssl-dev git build-essential autotools-dev autoconf libcurl3
sudo apt-get install libcurl4-gnutls-dev
git clone https://github.com/wolf9466/cpuminer-multi
sudo apt-get install cmake libpthread-* libmicrohttpd-dev libssl-dev libhwloc-dev
git clone https://github.com/fireice-uk/xmr-stak-cpu.git
chmod +x xmr-stak-cpu
./xmr-stak -O xmr........
This happened on Centos for no apparent reason with no obvious issue in the logs. Data could be read fine but not written (possibly due to some corruption or out of memory issue in the OpenVZ container is the best guess).
All mysql update and insert queries failed freezing without any error log on any database and table.
Tried to restart:
service mysqld restart
Timeout error occurred trying to stop MySQL........
Essentially a program I was running for mining did not terminate properly with Ctrl+C it is listed as defunct and cannot be killed, kernel is tainted and normal tricks to disable the port are impossible the dev and sys entries for the device cannot be browsed or interacted with in any form without a lockup of the request. The only solution is to reboot due to the kernel taint as far as I can find so far.
[1130246.811056] INFO: task minerd:21861 blocked for more th........
If Linux Mint 17 or other has no window buttons/controls you can do the following from terminal:
Sometimes it can be fixed if you go to your themes/appearance and choose a new one but in the case like mine where Compiz is installed but not running/working then that fix will not work and will require the marco command above.
What if you can't type in a terminal Window?
If you close........
ntpd: can't open /var/lib/ntp/drift.TEMP: Permission denied
chown ntp.ntp /var/lib/ntp/
The solution is shown above and changes the ownership to ntp.ntp which is what the ntpd daemon/server is running as. This is based on Centos but the same idea will apply on any other OS. You can do a "ps aux|grep ntpd" to see what it is running as in the case it's running as a different user.
After that this annoying message wil........
Virtualbox hang problem
A VM just froze and wouldn't close so I had to force it, but the VBox GUI thinks it's running even when I close it.
I manually killed the related process by doing ps aux|grep VirtualBox and found the PID 6191
I killed it with "kill -kill 6191" but it remains open and as "defunct" so I can't restart it because the GUI freezes when I click on it because it thinks it is running still........
I don't expect this to be solved soon but some of Yahoo's DNS servers are out of whack. I changed the IPs of some nameservers of some domains and now most Yahoo users can't e-mail to those domains!
As you can see below by the "No MX or A records for mychangedomain.com", now Yahoo's DNS/mailserver DNS cache is wrong. You would think they would at least have cached the old incorrect records, but instead for some reason their DNS cache has no entry and doesn't seem........
umount: /home/diret/mount: device is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
I tried everything (fusermount -u) to unmount it but the only thing that worked was actually doing this:
ps aux|grep sshfs
Then I identified the sshfs connection and did:
kill -kill pid........