I am trying to change the stack size on computing nodes, but no success so far.
I edited limits.pbs_mom, then restarted pbs_mom, but doesn't work.
Also edited pbs, then restarted pbs, still doesn't work.
used:
ulimit -H -s unlimited
ulimit -S -s unlimited
and ulimit -a looks fine.
Can anyone help me with it? Thank you very much in advance.
Related
I am getting the following error while running my rails app in Ubuntu server
FATAL: Listen error: unable to monitor directories for changes. Visit
https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers
for info on how to fix this.
I have followed the above GitHub page, but I was unable to write in max_user_watches which were set in 8192 and I want to set that to 524288.
in cat /proc/sys/fs/inotify/max_user_watches the file was in only read mode.I tried to grant write permissions, but I was getting permission denied error even with root access.
Thanks in Advance!!!
1000 is way too small, try with 524288 as explained in the wiki page: https://github.com/guard/listen/blob/master/README.md#increasing-the-amount-of-inotify-watchers
Listen uses inotify by default on Linux to monitor directories for
changes. It's not uncommon to encounter a system limit on the number
of files you can monitor. For example, Ubuntu Lucid's (64bit) inotify
limit is set to 8192.
and
If you are running Debian, RedHat, or another similar Linux
distribution, run the following in a terminal:
echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p
If you are running ArchLinux, run the following command instead
echo fs.inotify.max_user_watches=524288 | sudo tee /etc/sysctl.d/40-max-user-watches.conf && sudo sysctl --system
Just try to execute this from your console
echo fs.inotify.max_user_watches=524288 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p
Hope this will work for you .
References: click here
For others who may have this issue. I had a VM disconnect which left the previous rails server running. Running below resolved the issue without needing to up the number of watcher.
kill -9 $(lsof -i tcp:3000 -t)
In my case, I just need to turn off the terminal and then start it back again. It works when I try to run rails c command :)
Deleting Gemfile.lock and running 'bundle' in the project directory terminal worked for me.
This error occurred for me as I had a number of ruby processes currently running that I was unaware of. Just need to terminate them and all is good
I had this issue during development while running rake (even with rake -h), and the solution from https://github.com/guard/listen/wiki/Increasing-the-amount-of-inotify-watchers did not work, neither did killing the running ruby processes, killing the terminal or even restarting the computer.
To avoid this error I did a new and clean clone of my project and then rake was working (maybe git clean -fdx could have worked but I did not try it).
I was running rake version 13.0.3, rails 6.1.1, ruby 2.7.2p137.
Adding to #mayur-shah's answer,
It worked for me after closing the server and console. So, if you are running rails server/console, close that first.
My goal is to install and fully setup Postgresql by following railscast video.
P.S I am on a Mountain Lion 10.8
$ brew install postgresql
seems okay.
$ initdb /usr/local/var/postgres
ok's ok's then...
FATAL: could not create shared memory segment: Cannot allocate memory
DETAIL: Failed system call was shmget(key=1, size=2072576, 03600).
HINT: This error usually means that PostgreSQL's request for a shared memory segment exceeded available memory or swap space, or exceeded your kernel's SHMALL parameter. You can either reduce the request size or reconfigure the kernel with larger SHMALL. To reduce the request size (currently 2072576 bytes), reduce PostgreSQL's shared memory usage, perhaps by reducing shared_buffers or max_connections.
So like a good young SO grasshopper I start googling. and come to This SO post:
PostgreSQL installation error -- Cannot allocate memory
the suggested answer in this post lead me to this answer:http://willbryant.net/software/mac_os_x/postgres_initdb_fatal_shared_memory_error_on_leopard
$ sudo sysctl -w kern.sysv.shmall=65536
Password:
kern.sysv.shmall: 1024 -> 65536
$ sudo sysctl -w kern.sysv.shmmax=16777216
kern.sysv.shmmax: 4194304 -> 16777216
looks like everything worked so far, but in order to protect my changes from reboot, I need to update my /etc/sysctl.conf file. The problem is that I can't find it!
how do I locate this file? From my peanut sized understanding of computers, there is no filepath that exists, and if it did what is before the /etc ?? it certainly is not on my desktop. all I get is no such file exists, but I don't know how to find this file.
Embarrassing. I was trying to CD into my file. just do $ cd /etc
I'm using Icinga to monitor some servers and services. Most of them run fine. But now I like to monitor a JBoss-AS on one server via NRPE. Therefore I'm using the check_jboss-Plugin from MonitoringExchange. Although each time I try running a test-command from my Icinga-Server via NRPE I'm getting a NRPE: unable to read output error. When I try executing the command directly on the monitored server it runs fine. It's strange that the execution on the monitored server takes around 5 seconds to return a acceptable result but the NRPE-Exceution returns immediately the error. Trying to set up the NRPE-timeout didn't solve the problem. I also checked the permissions of the check_jboss-plugin and set them to "777" so that there should be no error.
I don't think that there's a common issue with NRPE, because there are also some other checks (e.g. check_load, check_disk, ...) via NRPE and they are all running fine. The permissions of these plugins are analog to my check_jboss-Plugin.
Following one sample exceuction on the monitored server which runs fine:
/usr/lib64/nagios/plugins/check_jboss.pl -T ServerInfo -J jboss.system -a MaxMemory -w 3000: -c 2000: -f
JBOSS OK - MaxMemory is 4049076224 | MaxMemory=4049076224
Here are two command-executions via NRPE from my Icinga-Server. Both commands are correctly
./check_nrpe -H xxx.xxx.xxx.xxx -c check_hda1
DISK OK - free space: / 47452 MB (76% inode=97%);| /=14505MB;52218;58745;0;65273
./check_nrpe -H xxx.xxx.xxx.xxx -c jboss_MaxMemory
NRPE: Unable to read output
Does anyone have a hint for me? If further config-information needed please ask :)
Try to rule out SELinux either by disabling it globally or by changing the SELinux type to nagios_unconfined_plugin_exec_t.
I'm running Mac OS 10.6. I want to run top to get memory usage, but not in interactive mode, or any mode that updates. I just want memory usage at that point in time then return to prompt. I've looked for other utilities to get memory usage... but came up short (vm_stat is for virtual memory). Can someone direct me how to get top or something else to print memory usage to stdout?
top -l 1 will put just one sample to standard output (you can redirect it, filter it, etc, as you wish of course). man top for many more details.
you can also use the ps command. eg
ps -eo pmem,comm
check the ps man page for more output formatting. eg rss, size etc..
I've been using this command to spit out the basic info in the first few lines
top -l 1 -n 0
-l 1 = just one sample
-n 0 = 0 processes
this is a bit of a hack .... but if you only want the memory line ... you could feed it through head and tail.
top -l 1 -n 0 | head -n 5 | tail -n 2
I am trying to learn to use buffer overflow attack in Ubuntu. Unfortunately, I cannot turn off Address Space Layout Randomization (ASLR) feature in this OS, which is turned on by default. I have tried some work around found in some fedora books:
echo "0" > /proc/sys/kernel/randomize_va_space
but for some reason the protection's still there. Please give me some suggestions. Thanks.
[edit]Actually the above command was not successful, it said "Permission Denied", even with sudo. How can I fix that?
[adding] I kept on getting segmetation fault error when it shows an address in stack. Is it related to non-executable stack in ubuntu :(?
You will need root perms before attempting it, and if I'm not mistaken, to restart once you've done it.
sudo -i
echo "0" > /proc/sys/kernel/randomize_va_space
found it myself
you have to compile this way:
gcc -fno-stack-protector -z execstack -o OUTPUT INPUT.c
to echo to files with root acces using sudo you can use the following code:
echo "0" | sudo tee /proc/sys/kernel/randomize_va_space
gcc compile with -fno-stack-protector
You can turn off ASLR for a particular process by launching with setarch
For 32 bit programs:
setarch i386 -R yourProgram
For 64 bit programs:
setarch x86_64 -R yourProgram